The UZPI ash content monitoring device

Energy Technology Data Exchange (ETDEWEB)

Novikov, E.P.; Bezverkhii, E.A.; Mozhaev, L.G.

1987-07-01

This paper describes the results of industrial trials (in coal preparation plants) to establish the accuracy of the UZPI device which determines coal ash content using X-ray detection. It is designed to monitor ash content in the 4-40% range in coal with a grain size of 0-100 mm and a coal layer thickness of 50-150 mm (depending on the ash content and grain size). The ash frequently contains oxides, and although variations in magnesium, aluminium, silicon and sulfur oxides have virtually no effect on accuracy of the UZPI, changes in the levels of calcium oxides and particularly iron oxides have a considerable influence on measurement accuracy (caused by changes in their gamma ray scattering cross section values and atomic numbers). The overall sensitivity to ash content in coal varies from 1.6 to 2.4% abs./% while that to iron oxides in ash is 0.4% abs./%. Concludes that this device is suitable for use in coal preparation plants on thin layers of coal, but its efficiency is affected by external influences, e.g. fluctuations in conveyor loading.

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.

Effect of mechanical activation of fly ash added to Moroccan Portland cement

Directory of Open Access Journals (Sweden)

Ez-zaki H.

2018-01-01

This study aims to investigate the influence of grinding fly ash on the physico-chemical and mechanical properties of fly ash blended CPJ45 cement. The addition of the fly ash particles to the grinder leads respectively to the breakage of the particles and to reduce the agglomeration effect in the balls of cement grinder. Fly ash milling was found to improve particles fineness, and increase the silica and alumina content in the cement. Furthermore, milled fly ash blended cements show higher compressive strength compared to unmilled fly ash blended cements, due to improved fly ash reactivity through their mechanical activation.

Improving lithium-ion battery performances by adding fly ash from coal combustion on cathode film

Energy Technology Data Exchange (ETDEWEB)

Dyartanti, Endah Retno; Jumari, Arif, E-mail: arifjumari@yahoo.com; Nur, Adrian; Purwanto, Agus [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

2016-02-08

A lithium battery is composed of anode, cathode and a separator. The performance of lithium battery is also influenced by the conductive material of cathode film. In this research, the use of fly ash from coal combustion as conductive enhancer for increasing the performances of lithium battery was investigated. Lithium iron phosphate (LiFePO{sub 4}) was used as the active material of cathode. The dry fly ash passed through 200 mesh screen, LiFePO{sub 4} and acethylene black (AB), polyvinylidene fluoride (PVDF) as a binder and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed to form slurry. The slurry was then coated, dried and hot pressed to obtain the cathode film. The ratio of fly ash and AB were varied at the values of 1%, 2%, 3%, 4% and 5% while the other components were at constant. The anode film was casted with certain thickness and composition. The performance of battery lithium was examined by Eight Channel Battery Analyzer, the composition of the cathode film was examined by XRD (X-Ray Diffraction), and the structure and morphology of the anode film was analyzed by SEM (Scanning Electron Microscope). The composition, structure and morphology of cathode film was only different when fly ash added was 4% of AB or more. The addition of 2% of AB on cathode film gave the best performance of 81.712 mAh/g on charging and 79.412 mAh/g on discharging.

Adding Value to Ash and Digestate (AVAnD). AN Integrated Overview of the Effects of Ash and Digestate Blends on the Soil-Plant System.

Science.gov (United States)

Lag-Brotons, Alfonso; Marshall, Rachel; Herbert, Ben; Hurst, Lois; Ostle, Nick; Dodd, Ian C.; Quinton, John; Surridge, Ben; Aiouache, Farid; Semple, Kirk T.

2017-04-01

Resource recovery from waste could play a central role in strategies tackling current worldwide sustainability problems. Focusing on the agricultural sector, waste streams represent an opportunity to break the cycle of nutrients depletion (exported with crop biomass) and incorporation by non-sustainable means such the use of inorganic fertilisers (either finite and/or highly energy intensive in their production). In this sense, digestate [D], from anaerobic digestion, and biomass ash [A], from incineration, are especially valuable since they supply, amongst other nutrients, nitrogen [N] and phosphorus [P], respectively. Whilst these waste streams could be highly heterogeneous, in general terms they present a complementary nutritional profile which could be exploited for the production of alternative fertilisers. This is precisely the overarching aim of the "Adding Value to Ash and Digestate [AVAnD]" project: the identification of a novel nutrient-recycling pathway to maximise soil quality and crop productivity utilising waste streams derived from bioenergy production. However, the application to land of novel recycled and recovered products entails the assessment of the biological and chemical interactions and the implications for ecosystems, to determine desirable and detrimental effects that might arise. Therefore, we aim to provide an insight on the AVAnD project and briefly describe and discuss some of the findings obtained so far. Experiments were carried out at different scales and under different conditions using two different digestates ([D1], [D2]) and two ash fractions (fly [A1] and bottom [A2]). The main factor considered was fertiliser type including A/D blends, A & D alone, no fertilisation and inorganic fertilisers. Fertilisation target (63/60 kg N/P2O5 per ha) was the same across the different fertiliser materials. Aspects covered included nutrient availability (N-, P- forms), soil properties (DOC, pH, EC), greenhouse gas emissions (CO2, N2O) and

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum

Science.gov (United States)

Mikhailov, I. F.; Baturin, A. A.; Mikhailov, A. I.; Borisova, S. S.; Fomina, L. P.

2018-02-01

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

Residual oil fly ash induces cytotoxicity and mucin secretion by guinea pig tracheal epithelial cells via an oxidant-mediated mechanism.

Science.gov (United States)

Jiang, N; Dreher, K L; Dye, J A; Li, Y; Richards, J H; Martin, L D; Adler, K B

2000-03-15

Inhalation of ambient air particulate matter (PM) is associated with pulmonary injury and inflammation. Using primary cultures of guinea pig tracheal epithelial (GPTE) cells as an in vitro model of airway epithelium, we examined effects of exposure to suspensions of six different emission and ambient air PM samples: residual oil fly ash (ROFA) from an electrical power plant; fly ash from a domestic oil burning furnace (DOFA); ambient air dust from St. Louis (STL), Ottawa (OT), and Washington, DC (WDC); and volcanic ash from the eruption of Mount Saint Helens (MSH) in 1980. Effects of these particulates on cell viability (assessed via LDH assay), secretion of mucin (measured by a monoclonal antibody-based ELISA), and steady-state mRNA levels of the mucin gene MUC2 were determined. ROFA was the most toxic of the dusts tested, as it significantly increased LDH release following a 24-h incubation with 50 microg/cm(2) ROFA. ROFA also enhanced MUC2 mRNA after 4-h exposure, and mucin secretion after 8 h. ROFA-induced mucin secretion and cytotoxicity were attenuated by the oxidant scavenger, dimethylthiourea (DMTU). ROFA exposure also depleted cells of glutathione (GSH). Relatedly, depletion of intracellular GSH by treatment of the cells with buthionine sulfoxamine (BSO) also provoked mucin secretion, as well as enhancing the secretory effect of ROFA when the two agents were added together. L-NMA, the nitric oxide synthase (NOS) inhibitor, did not affect ROFA-induced mucin secretion. Of the soluble transition metals in ROFA (nickel, iron, vanadium), only vanadium individually, or combinations of the metals containing vanadium, provoked secretion. The results suggest ROFA enhances mucin secretion and generates toxicity in vitro to airway epithelium via a mechanism(s) involving generation of oxidant stress, perhaps related to depletion of cellular antioxidant capacity. Deleterious effects of inhalation of ROFA in the respiratory tract in vivo may relate to these cellular

Reuse of partially sulphated CFBC ash as an SO{sub 2} sorbent

Energy Technology Data Exchange (ETDEWEB)

Wu, Y.; Jia, L.; Anthony, E.J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy; Nobili, M.; Telesca, A. [Basilicata Univ., Potenza (Italy). Dept. of Environmental Engineering and Physics; Montagnaro, F. [Naples Univ., Naples (Italy). Dept. of Chemistry

2010-06-15

Ash produced from circulating fluidized bed combustion (CFBC) boilers typically contains large amounts of unreacted calcium oxide (CaO) when limestone is added into the combustor for in situ removal of sulphur dioxide (SO{sub 2}). This paper reported on a study that evaluated the reactivation of partially sulphated ash obtained from an industrial circulating fluidized bed combustion (CFBC) boiler by hydration with liquid water and steam. A pilot-scale mini-CFBC was used to evaluate the results of reactivation on the bed ash by hydrating with liquid water and admixtures of sodium carbonate (Na{sub 2}CO{sub 3}) in solution or as powder. Re-sulphation tests on the hydrated samples were performed in a Cahn 1000 thermogravimetric analyzer (TGA) at 850 degrees C for 90 minutes in a simulated flue gas environment with sulphur dioxide (SO{sub 2}) concentration at 5000 ppm. Re-sulphation was carried out on unhydrated ash at the same conditions used in the baseline test. The TGA results showed that although liquid water and steam successfully hydrate and reactivate the unreacted CaO in the bed ash, the treated ashes sulphated to widely different extents. Attempts to reactivate fly ash with hydration failed, but the fly ash by itself was extremely reactive. When the treated ash was re-injected into the combustor with the fuel, the effect on SO{sub 2} removal efficiency was negligible if Na{sub 2}CO{sub 3} was added as powder. Doping with aqueous solution improved SO{sub 2} removal, but to a lesser extent than if only water hydration was used. Increasing the amount of water to reactivate the ash did not improve the sulphur capture capacity in the mini-CFBC. It was concluded that reactivation by water is the most practical way to reuse the partially sulphated bed ash as a sulphur sorbent. 21 refs., 7 tabs., 3 figs.

KINETICS OF FLY ASH BENEFICIATION BY CARBON BURNOUT

Energy Technology Data Exchange (ETDEWEB)

Dr. Joseph N.D. Dodoo; Dr. Joseph M. Okoh

2000-11-01

Surface area analyses performed on fly ash samples reveal that the surface area is controlled by carbon content. The higher surface areas found in large particles are due to the presence of highly porous carbonaceous particles. Adsorption-desorption isotherms and t-plots of fly ash samples indicate that fly ash is porous. BJH Adsorption/Desorption pore size analysis reveal that pore diameters are independent of sieve size. They appear to be dependent only on the nature of the material which confers porosity. Based on the results of Brown and Dykstra (41) it is reasonable to assume that calculations of reaction rates at temperatures above 550 C were confounded by weight losses from processes other than carbon oxidation and, therefore, are not useful in determination of the temperature dependence of carbon oxidation in fly ash. The results of the present study indicate that temperatures below 550 C should be used for future studies in order to satisfactorily assess the temperature dependence of carbon oxidation in fly ash. Furthermore, it is also advisable that percent carbon determinations be performed on fly ash samples after the oxidation reactions to determine whether all carbon present in fly ash is oxidized. This will ensure that reaction rates are representative of the complete oxidation of carbon. An inverse relationship was determined between reaction rates and oxygen concentration for this study. As discussed, this may be due to volatilization of volatiles from fly ash and ease of transport of products away from the reaction sites by the action of the vacuum applied to the samples. A more accurate determination of oxygen dependence of carbon oxidation can be accomplished by the use of specialty gases containing different concentrations of oxygen which could eliminate the need to apply vacuum to the samples.

Attenuation of pyrite oxidation with a fly ash pre-barrier: Reactive transport modelling of column experiments

Energy Technology Data Exchange (ETDEWEB)

Perez-Lopez, R.; Cama, J.; Nieto, J.M.; Ayora, C.; Saaltink, M.W. [University of Huelva, Huelva (Spain). Dept. of Geology

2009-09-15

Conventional permeable reactive barriers (PRBs) for passive treatment of groundwater contaminated by acid mine drainage (AMD) use limestone as reactive material that neutralizes water acidity. However, the limestone-alkalinity potential ceases as inevitable precipitation of secondary metal-phases on grain surfaces occurs, limiting its efficiency. In the present study, fly ash derived from coal combustion is investigated as an alternative alkalinity generating material for the passive treatment of AMD using solution-saturated column experiments. Unlike conventional systems, the utilization of fly ash in a pre-barrier to intercept the non-polluted recharge water before this water reacts with pyrite-rich wastes is proposed. Chemical variation in the columns was interpreted with the reactive transport code RETRASO. In parallel, kinetics of fly ash dissolution at alkaline pH were studied using flow-through experiments and incorporated into the model. In a saturated column filled solely with pyritic sludge-quartz sand (1: 10), oxidation took place at acidic conditions (pH 3.7). According to SO{sub 4}{sup 2-} release and pH, pyrite dissolution occurred favourably in the solution-saturated porous medium until dissolved O{sub 2} was totally consumed. In a second saturated column, pyrite oxidation took place at alkaline conditions (pH 10.45) as acidity was neutralized by fly ash dissolution in a previous level. At this pH Fe release from pyrite dissolution was immediately depleted as Fe-oxy(hydroxide) phases that precipitated on the pyrite grains, forming Fe-coatings (microencapsulation). With time, pyrite microencapsulation inhibited oxidation in practically 97% of the pyritic sludge. Rapid pyrite-surface passivation decreased its reactivity, preventing AMD production in the relatively short term.

Enhancement of mercury capture by the simultaneous addition of hydrogen bromide (HBr) and fly ashes in a slipstream facility.

Science.gov (United States)

Cao, Yan; Wang, Quan-Hai; Li, Jun; Cheng, Jen-Chieh; Chan, Chia-Chun; Cohron, Marten; Pan, Wei-Ping

2009-04-15

Low halogen content in tested Powder River Basin (PRB) coals and low loss of ignition content (LOI) in PRB-derived fly ash were likely responsible for higher elemental mercury content (averaging about 75%) in the flue gas and also lower mercury capture efficiency by electrostatic precipitator (ESP) and wet-FGD. To develop a cost-effective approach to mercury capture in a full-scale coal-fired utility boiler burning PRB coal, experiments were conducted adding hydrogen bromide (HBr) or simultaneously adding HBr and selected fly ashes in a slipstream reactor (0.152 x 0.152 m) under real flue gas conditions. The residence time of the flue gas inside the reactorwas about 1.4 s. The average temperature of the slipstream reactor was controlled at about 155 degrees C. Tests were organized into two phases. In Phase 1, only HBr was added to the slipstream reactor, and in Phase 2, HBr and selected fly ash were added simultaneously. HBr injection was effective (>90%) for mercury oxidation at a low temperature (155 degrees C) with an HBr addition concentration of about 4 ppm in the flue gas. Additionally, injected HBr enhanced mercury capture by PRB fly ash in the low-temperature range. The mercury capture efficiency, attesting conditions of the slipstream reactor, reached about 50% at an HBr injection concentration of 4 ppm in the flue gas. Compared to only the addition of HBr, simultaneously adding bituminous-derived fly ash in a minimum amount (30 lb/MMacf), together with HBr injection at 4 ppm, could increase mercury capture efficiency by 30%. Injection of lignite-derived fly ash at 30 lb/MMacf could achieve even higher mercury removal efficiency (an additional 35% mercury capture efficiency compared to HBr addition alone).

Supercritical water oxidation of dioxins and furans in waste incinerator fly ash, sewage sludge and industrial soil.

Science.gov (United States)

Zainal, Safari; Onwudili, Jude A; Williams, Paul T

2014-08-01

Three environmental samples containing dioxins and furans have been oxidized in the presence of hydrogen peroxide under supercritical water oxidation conditions. The samples consisted of a waste incinerator fly ash, sewage sludge and contaminated industrial soil. The reactor system was a batch, autoclave reactor operated at temperatures between 350 degrees C and 450degrees C, corresponding to pressures of approximately 20-33.5 MPa and with hydrogen peroxide concentrations from 0.0 to 11.25 vol%. Hydrogen peroxide concentration and temperature/pressure had a strong positive effect on the oxidation of dioxins and furans. At the highest temperatures and pressure of supercritical water oxidation of 4500C and 33.5 MPa and with 11.25 vol% of hydrogen peroxide, the destruction efficiencies of the individual polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) isomers were between 90% and 99%. There did not appear to be any significant differences in the PCDD/PCDF destruction efficiencies in relation to the different sample matrices of the waste incinerator fly ash, sewage sludge and contaminated industrial soil.

Adding Value to Ash and Digestate (AVAnD): Performance of Novel Soil Amendents on the Soil-Plant System Under Glasshouse Conditions

Science.gov (United States)

Lag-Brotons, Alfonso; Marshall, Rachel; Herbert, Ben; Hurst, Lois; Ostle, Nick; Dodd, Ian; Quinton, John; Surridge, Ben; Aiouache, Farid; Semple, Kirk T.

2017-04-01

Resource recovery from waste plays a central role in strategies tackling current worldwide sustainability problems. In this sense, two waste streams derived from bioenergy production (anaerobic digestion and incineration), digestate [D] and biomass ash [A], may be especially valuable within agriculture. These materials offer complementary plant nutrient profiles for alternative fertiliser production (i.e. nitrogen [N] from D and phosphorus [P] from A). In addition, incorporating these materials into the soil could impact upon several soil/plant characteristics, and have positive effects on ecosystem services (eg. nutrient cycling). Therefore, this present work assessed the effects of A/D blends on the soil-plant system under controlled conditions (glasshouse). The overarching aim of "Adding Value to Ash and Digestate [AVAnD]" project is to identify novel nutrient-recycling pathways to maximise soil quality and crop productivity utilising waste streams derived from bioenergy production. Two pot experiments of 6 weeks duration were carried out [Exp. A and Exp. B] using contrasting agricultural soils (neutral loam and sandy acidic soil) and wheat as the crop. A factorial randomised block design was selected, with fertilisation treatment and soil condition (planted/unplanted) as factors. Fertilisation treatments (n=13) were applied at a rate of 63/60 kg N/P2O5 per ha and comprised: control ([C], no fertilisation), urea [U], urea+superphosphate [U+P], fly ash [A1], bottom ash [A2], U+A1; U+A2, anaerobic digestates [D1, D2] and ash/digestate blends [D1A1, D1A2, D2A1, D2A2]. Each block (n=5) contained 8 planted and 5 unplanted pots (104 planted + 65 unplanted experimental units). At the end of the experiment, all the plants were assessed for morphometric traits, while for tissue elemental analyses the total number of replicates per treatment was randomly reduced (n=5/treatment). Soil physico-chemical properties (i.e. available nitrogen, pH) were assessed in unplanted and

Strength Characteristics of Fiber Reinforced Quarry Dust Stabilized Fly Ash

OpenAIRE

Akshaya Kumar Sabat; Bidula Bose

2015-01-01

Effects of quarry dust and polypropylene fiber on compaction properties, shear strength parameters, and California bearing ratio (CBR) of a fly ash have been discussed in this paper. Quarry dust was added to a fly ash from 0 to 60% at an increment of 10%, compaction and soaked CBR tests were conducted on fly ash-quarry dust mixes and the optimum percentage of quarry dust was found out to be 40%. Polypropylene fiber was added to fly ash stabilized with optimum percentage of quarry dust, from 0...

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.

Continuous CO2 capture and MSWI fly ash stabilization, utilizing novel dynamic equipment

International Nuclear Information System (INIS)

Jiang Jianguo; Du Xuejuan; Chen Maozhe; Zhang Chang

2009-01-01

Novel dynamic equipment with gas in and out continuously was developed to study the capture capacity of CO 2 . Municipal solid waste incineration (MSWI) fly ash has a high capture rate of CO 2 in CO 2 -rich gas. Fly ash can sequester pure CO 2 rapidly, and its capacity is 16.3 g CO 2 /100 g fly ash with no water added and 21.4 g CO 2 /100 g fly ash with 20% water added. For simulated incineration gas containing 12% CO 2 , the capture rate decreased and the capacity was 13.2 g CO 2 /100 g fly ash with no water added and 18.5 g CO 2 /100 g fly ash with 20% water added. After accelerated carbonation, the C and O contents increased, indicating CO 2 capture in the fly ash; CO 2 combines with Ca(OH) 2 to form CaCO 3 , which increased the CaCO 3 content from 12.5 to 54.3%. The leaching of Pb markedly decreased from 24.48 to 0.111 mg/L. - Novel dynamic equipment designed to capture CO 2 by fly ash is more suitable for engineering application.

Physical, chemical and mineralogical properties of fly ash

International Nuclear Information System (INIS)

Khairul Nizar Ismail; Kamaruddin Hussin; Mohd Sobri Idris

2007-01-01

Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Fly ash particles are generally spherical in shape and range in size from 2 μm to 10 μm. They consist mostly of silicon dioxide (SiO 2 ), aluminium oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ). Fly ash like soil contains trace concentrations of the following heavy metals: nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F. (Author)

Granulated wood ash to forest soil - Ecological effects

International Nuclear Information System (INIS)

Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

1993-01-01

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

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.

Thermal treatment of ashes[Fly Ash from Municipal Waste Incineration]; Termisk rening av askor

Energy Technology Data Exchange (ETDEWEB)

Wikman, Karin; Berg, Magnus; Bjurstroem, Henrik [AaF-Energi och Miljoe AB, Stockholm (Sweden); Nordin, Anders [Umeaa Univ. (Sweden). Dept. of Applied Physics and Electronics

2003-04-01

In this project descriptions of different processes for thermal treatment of ashes have been compiled. A technical and economic evaluation of the processes has been done to identify possibilities and problems. The focus in the project lays on treatment of fly ash from municipal waste incineration but the processes can also be used to treat other ashes. When the ash is heated in the thermal treatment reactor, with or without additives, the material is sintered or vitrified and at the same time volatile substances (Zn, Pb, Cd, Hg etc.) are separated. In general the separation is more effective in processes with reducing conditions compared to oxidizing conditions. Oxidizing processes have both worse separation capacity and require more energy. The oxidizing processes are mainly used to stabilize the ash through vitrification and they are in some cases developed for management of municipal sewage sludge and bottom ash. However, these processes are often not as complex as for example an electric arc melting furnace with reducing conditions. The research today aim to develop more effective electrical melting systems with reducing conditions such as plasma melting furnaces, electric resistance melting furnaces and low frequency induction furnaces. A central question in the evaluation of different thermal treatment processes for ash is how the residues from the treatment can be used. It is not certain that the vitrified material is stable enough to get a high economic value, but it can probably be used as construction material. How the remaining metals in the ash are bound is very important in a long-time perspective. Further studies with leaching tests are necessary to clarify this issue. The heavy metal concentrate from the processes contains impurities, such as chlorine, which makes it unprofitable to obtain the metals. Instead the heavy metal concentrate has to be land filled. However, the amount of material for land filling will be much smaller if only the heavy

Facing slag glass and slag glass ceramic produced from thermal power plant ash

Energy Technology Data Exchange (ETDEWEB)

Buruchenko, A.E.; Kolesnikov, A.A.; Lukoyanov, A.G.

1990-10-01

Evaluates properties of fly ash and slags from the Krasnoyarsk coal-fired power plants and their utilization for glass and ceramic glass production. Composition of a mixture of fly ash and slag was: silica 40-55%, aluminium oxides 10-40%, ferric trioxide 6-14%, calcium oxides 20-35%, magnesium oxides 3-6%, potassium oxides 0.3-1.5%, sodium oxides 0.2-05%, sulfur trioxide 0.9-5.0%. The analyzed fly ash and slags from the Krasnoyarsk plant were an economic waste material for glass production. Properties of sand, clay and other materials used in glass production and properties of glass and ceramic glass produced on the basis of fly ash and slags are analyzed. Economic aspects of fly ash and slag utilization are also evaluated. 3 refs.

Oxidative stability of yogurt with added lutein dye.

Science.gov (United States)

Domingos, L D; Xavier, A A O; Mercadante, A Z; Petenate, A J; Jorge, R A; Viotto, W H

2014-02-01

This study evaluated the effect of adding lutein dye on the oxidative stability of yogurt during 35 d of refrigerated storage, in the presence and absence of light. Yogurts manufactured without and with the equivalent of 1.5mg of lutein in 120 g of the final product were characterized for their total carotenoid and riboflavin contents, and the behaviors of both riboflavin and lutein were monitored during storage. A decrease in riboflavin content occurred, with concurrent appearance of its derived-oxidation products in the yogurts without added lutein and exposed to light during storage. The yogurts with added lutein dye showed constant lutein and riboflavin contents throughout storage both for the samples stored under light and for those stored in the dark. Yogurts (120 g) with the addition of 0.5, 1.5, and 2.5mg of lutein dye were evaluated for their sensory acceptance, and the statistical analysis showed no differences between the samples for the attributes of aroma and flavor. These results indicate that the added lutein remained stable throughout the storage period and conferred protection for the riboflavin against photooxidation, preserving the quality of the yogurts. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

International Nuclear Information System (INIS)

Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

2014-01-01

Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

Characterization of ash in algae and other materials by determination of wet acid indigestible ash and microscopic examination

Science.gov (United States)

Algae are known for high ash content. It is important to properly characterize their ash for value added utilization of algae as food, feed, and feedstock for biofuels. In this study, 12 algae of different sources were measured for proximate composition and mineral profile. Results showed that the r...

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

Cs-137 in biofuel and reuse of the ash; Radiocesium i biobraenslen och aateranvaendning av askan

Energy Technology Data Exchange (ETDEWEB)

Johanson, K. J. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

1999-07-01

The activity concentration of {sup 137}Cs in sheep fescue grown in pots where ashes had been added to forest soil were studied. The added ash corresponded to 3000 kg per hectare and were either mixed into the forest soil or spread above the soil. The results were expressed as percentage of control value from sheep fescue grown on the same forest soil but without adding ash. In the first harvest the {sup 137}Cs were 60 and 33 % of the control value in the pots where fly ash respectively wet ash was mixed with the forest soil before starting the experiment. In the pots where the ash was spread on the soil 80 and 76 % of control values were found in fly ash respectively wet ash pots. In the second harvest 87 and 10 % of control values were found in fly ash respectively wet ash in the pots where ash were mixed with soil. The corresponding values in pots where the ash was spread on the soil were 31 respectively 42 %. The results show that we probably can expect at least a 50 % decrease in the {sup 137}Cs activity concentrations after adding ash particularly if the ash is spread on the soil. There will take a certain time before the optimal reduction occur and after spreading in the forest there will probably take one year before maximum reduction is obtained. In a field experiment using potassium fertilization we obtained about the same reduction in {sup 137}Cs levels in bilberry, lingonberry and heather and also in some fungal species. The reduction could be seen even after 7 vegetation periods. It thus seems that the adding of ash to forest soil should be a rather effective counter measure with expected reduction of {sup 137}Cs levels of about 50 %.

Influence of inorganic compounds on the combustion of coal. III. The effect of water of constitution of added compounds, moisture, and mineral matter in coal

Energy Technology Data Exchange (ETDEWEB)

Newall, H F

1939-01-01

The effects on the combustion rate from excess moisture and the addition of selected inorganic substances to powdered coals were determined. The catalytic effect of 19 known inorganic ash constituents on combustion rates was also examined. Alumina and silica were found to inhibit combustion while ferric oxide accelerated it. Titanium, Ge, and B oxides, along with gypsum and calcium phosphate, decreased the rate of combusion, while Ca, Mg, Mn, and V oxides increased combustion rates. Although several of the ash constituents in coal directly affected combustion rates, the effect of adding them to the coal prior to combustion did not correlate with the effect of the mineral matter already in the coal.

Effects of chemical composition of fly ash on efficiency of metal separation in ash-melting of municipal solid waste

Energy Technology Data Exchange (ETDEWEB)

Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp [Laboratory of Solid Waste Disposal Engineering, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan); Tomikawa, Hiroki [Laboratory of Solid Waste Disposal Engineering, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan)

2013-03-15

Highlights: ► Separation of Pb and Zn from Fe and Cu in ash-melting of municipal solid waste. ► Molar ratio of Cl to Na and K in fly ash affected the metal-separation efficiency. ► The low molar ratio and a non-oxidative atmosphere were better for the separation. - Abstract: In the process of metal separation by ash-melting, Fe and Cu in the incineration residue remain in the melting furnace as molten metal, whereas Pb and Zn in the residue are volatilized. This study investigated the effects of the chemical composition of incineration fly ash on the metal-separation efficiency of the ash-melting process. Incineration fly ash with different chemical compositions was melted with bottom ash in a lab-scale reactor, and the efficiency with which Pb and Zn were volatilized preventing the volatilization of Fe and Cu was evaluated. In addition, the behavior of these metals was simulated by thermodynamic equilibrium calculations. Depending on the exhaust gas treatment system used in the incinerator, the relationships among Na, K, and Cl concentrations in the incineration fly ash differed, which affected the efficiency of the metal separation. The amounts of Fe and Cu volatilized decreased by the decrease in the molar ratio of Cl to Na and K in the ash, promoting metal separation. The thermodynamic simulation predicted that the chlorination volatilization of Fe and Cu was prevented by the decrease in the molar ratio, as mentioned before. By melting incineration fly ash with the low molar ratio in a non-oxidative atmosphere, most of the Pb and Zn in the ash were volatilized leaving behind Fe and Cu.

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

Science.gov (United States)

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

2016-06-01

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

Ash fell from the skies to the earth: The eruption of the Vesuvius in 1631 AD and the Balkan lands

Directory of Open Access Journals (Sweden)

Mrgić Jelena

2004-01-01

Full Text Available After the most notorious eruption of the Vesuvius in 79 AD, the one that occurred on 16th December 1631 resulted in thousands of human victims and large-scale damage. According to modern volcanology studies, the amount of dust and ash emitted on this occasion was only three times smaller that in the famous eruption of Krakatau in 1883. Numerous historical sources registered the fall of volcanic ash, which is proved to be the true meaning of three Serbian marginal notes presented in this article. Anonymous monks in the monasteries of St. George near Pljevlja, Pološko and another one which still cannot be precisely identified, reported the fallout of ash on Wednesday, December 7, according to the Julian, i.e. 17 according to the Gregorian calendar. Considering the velocity of ash clouds, it is assumed that in both cases it could have been the first thing they saw at dawn, on the day after the eruption (cf. the map in this paper. Along with the "black powder", the same kind of historical sources - Serbian marginal notes, and The Chronicle of Fra Nikola Lašvanin - also provide the data on "red/bloody snow" on three separate occasions (1638, 1640 and 1690. These phenomena can be scientifically explained as deposits of desert dust from northern Africa brought by south-southwest air currents over the Balkan region. The last issue discussed in this paper is the possible connection between this particular volcanic eruption and short-term climate changes it may have caused in the Balkans.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-06-01

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

Effects of ashes in solid fuels on fuel particle charging during combustion in an air stream

Energy Technology Data Exchange (ETDEWEB)

Zakharov, A.G.; Fialkov, B.S.; Mel' nichuk, A.Yu.; Khvan, L.A.

1982-09-01

Black coal from the Karaganda basin is mixed with sodium chloride and graphite. Coal characteristics are given in a table (density, ashes, content of silica, aluminium oxides, iron oxides, calcium oxides, potassium oxides and magnesium oxides). Effects of ash fluctuations on electric potential of fuel particles during combustion are analyzed. Analyses show that with increasing ash content electric potential of fuel particles decreases and reaches the minimum when ash content ranges from 70 to 80 %. Particles with electric potential are generated during chemical processes between carbon and oxygen when coal is burned in an air stream. (5 refs.) (In Russian)

Corrosion behavior of Fe-Si metallic coatings added with NiCrAlY in an environment of fuel oil ashes at 700 C

Energy Technology Data Exchange (ETDEWEB)

Salinas-Bravo, V.M.; Porcayo-Calderon, J.; Romero-Castanon, T. [Instituto de Investigaciones Electricas, Gerencia de Procesos Termicos., Av. Reforma 113, C.P. 62490 Col. Palmira. Temixco. Morelos (Mexico); Dominguez-Patino, G.; Gonzalez-Rodriguez, J.G. [U.A.E.M. Centro de Investigaciones en Ingenieria y Ciencias Aplicadas., Av. Universidad 1001, C.P. 62210, Col. Chamilpa. Cuernavaca, Morelos (Mexico)

2005-07-01

Electrochemical potentiodynamic polarization curves and immersion tests for 300 h at 700 C in a furnace have been used to evaluate the corrosion resistance of Fe-Si metallic coatings added with up to 50 wt.% of NiCrAIY. The corrosive environment was fuel oil ashes from a steam generator. The composition of fuel oil ashes includes high content of vanadium, sodium and sulfur. The results obtained show that only the addition of 20 wt.% NiCrAlY to the Fe-Si coating improves its corrosion resistance. The behavior of all tested coatings is explained by the results obtained from the analysis of every coating using electron microscopy and energy dispersive X-ray analysis. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

The Optimization of Calcareous Fly Ash-Added Cement Containing Grinding Aids and Strength-Improving Additives

Directory of Open Access Journals (Sweden)

Gökhan Kaplan

2018-01-01

Full Text Available This is an experimental study which explores the physical, mechanical, and economic factors involved in the production of type CEM II A-B/W cement. In this context, 4 cement additives were used in two different dosages (200 and 800 g/t. Class C fly ash was used for composite cement production at ratios of 5%, 20%, and 35%. It was shown that Blaine fineness increases with the increasing fly ash content. The use of fly ash at ratios of 5% and 20% was not found to have any unfavorable effects on the compressive strength at the early days. It is found that the use of additive for improving the early-age strength is preferable when fly ash is used. It is possible to produce Class 52.5 N cement using additives to improve early strength and 20% fly ash. Loss in strength was observed in cement mortars produced using glycol-based grinding aid. Increasing the dosage of chemical additive also led to loss in strength due to nonhomogeneous distribution of hydration products. As a result, grinding fly ash with clinker and the use of cement chemicals contribute to the cement sector in terms of sustainability. It is possible to produce cements with improved mechanical properties especially with the use of 20% fly ash.

Use of ash in the fertilisation of peatland forests

International Nuclear Information System (INIS)

Moilanen, M.; Korpilahti, A.

2000-01-01

About 100,000 tonnes of bark and other wood-based ash are produced annually by the forest industries and heating plants in Finland. This amount would be sufficient for fertilising about 25,000 hectares of forest. When applied to peatland forests, this would produce extra forest growth of about 75,000 m 3 per a year. When considering the objectives of forestry, the practical benefits and economic profitability of ash fertilisation are at their peak on peatlands rich in nitrogen. Wood ash induces added tree growth (measured in terms of stemwood) in pine stands on herb- and sedge-rich parklands within 2-3 years of application. On nitrogen-deficient dwarf-shrub and Sphagnum-rich peatlands this growth reaction manifests itself only after 7-8 years have passed and even then at a considerably lower level. The application of mere ash does not result in notable increases in tree growth on upland forest sites. However, ash does change the growth conditions by reducing the acidity of the soil and by accelerating microbial decomposition. The phosphorus contained in ash has not been observed to have been leached into drainage waters on drained sites, at least not during the first two years after application, provided that care has been practised when spreading ash. However, the movement of readily-soluble nutrients has been observed and more so on nutrient-poor sites than on nutrient-rich sites. Although the suitability of ash as fertiliser in peatland forests has been recognised on the basis of long-term ash trials established at the Finnish Forest Research Institute, ash fertilisation has not been carried out made on a practical scale mainly because of the dust problem when spreading it. The purpose of pretreatment with ash is first and foremost to transform the ash into sufficiently dust-free form to enable it to be spread readily. An added advantage is that pelletised ash causes a lesser pH shock to plank than ash in dust form. (orig.)

Characterization of metals released from coal fly ash during dredging at the Kingston ash recovery project.

Science.gov (United States)

Bednar, A J; Averett, D E; Seiter, J M; Lafferty, B; Jones, W T; Hayes, C A; Chappell, M A; Clarke, J U; Steevens, J A

2013-09-01

A storage-pond dike failure occurred on December 22, 2008 at the Tennessee Valley Authority Kingston Fossil Plant resulting in the release of over 4million cubic meters (5million cubic yards) of fly ash. Approximately half of the released ash was deposited in the main channel of the Emory River, Tennessee, USA. Remediation efforts of the Emory River focused on hydraulic dredging, as well as mechanical excavation in targeted areas. However, agitation of the submerged fly ash during hydraulic dredging introduces river water into the fly ash material, which could promote dissolution and desorption of metals from the solid fly ash material. Furthermore, aeration of the dredge slurry could alter the redox state of metals in the fly ash material and thereby change their sorption, mobility, and toxicity properties. The research presented here focuses on the concentrations and speciation of metals during the fly ash recovery from the Emory River. Our results indicate that arsenite [As(III)] released from the fly ash material during dredging was slowly oxidized to arsenate [As(V)] in the slurry recovery system with subsequent removal through precipitation or sorption reactions with suspended fly ash material. Concentrations of other dissolved metals, including iron and manganese, also generally decreased in the ash recovery system prior to water discharge back to the river. Published by Elsevier Ltd.

Gasification of high ash, high ash fusion temperature bituminous coals

Science.gov (United States)

Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

2015-11-13

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

Ash reduction system using electrically heated particulate matter filter

Science.gov (United States)

Gonze, Eugene V [Pinckney, MI; Paratore, Jr., Michael J; He, Yongsheng [Sterling Heights, MI

2011-08-16

A control system for reducing ash comprises a temperature estimator module that estimates a temperature of an electrically heated particulate matter (PM) filter. A temperature and position estimator module estimates a position and temperature of an oxidation wave within the electrically heated PM filter. An ash reduction control module adjusts at least one of exhaust flow, fuel and oxygen levels in the electrically heated PM filter to adjust a position of the oxidation wave within the electrically heated PM filter based on the oxidation wave temperature and position.

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.

Reuse of Partially Sulphated CFBC Ash as an SO2 Sorbent

Energy Technology Data Exchange (ETDEWEB)

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

2010-06-15

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

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...

The stability of clay using volcanic ash of Mount Sinabung North Sumatera and sugarcane bagasse ash with cbr and uct value

Directory of Open Access Journals (Sweden)

Hastuty Ika Puji

2017-01-01

Full Text Available Soil is the fundamental material that is extremely as the place of establishment of a structure or construction, both building and road constructions. However, not all soil is well used in the constructions field, as there are several types of soil that are problematic in terms of both the soil bearing capacity and deformation. The clay with carrying capacity and low shear strength needs to stabilized in order to meet the technical requirements to be used as sub grade. The add materials that are typically used for soil stabilization are cement, lime or a mixture of two or three of the added materials. In this study, the added material use volcanic ash of Mount Sinabung at North Sumatera and sugarcane bagasse ash. The purpose of this study was to determine an index value of properties as the result of the addition of 4% volcanic ash and variations in content of bagasse ash on clay and then to determine the compressive strength for maximum testing UCT (Unconfined Compression Test and understand the value of CBR (California Bearing Capacity as the consequence of the addition of a stabilizing agent, as well as optimum level of addition of bagasse ash. The result showed that the original soil sample has the water content 12.35%, specific gravity of 2.65, liquid limit of 46.73% and plasticity index of 26.44%. The compressive strength value of 1.38 kg/cm2. Base on the USCS classification, the soil sample including the type CL while base on AASHTO classification, soil samples are include this A-7-6 type. After the soil is stabilized with a wide variety of sugarcane bagasse ash content value obtained the largest unconfined compression test in 4% addition level volcanic ash + 10% sugarcane bagasse ash is equal to 5.1kg/cm2 and the result California Bearing capacity value on the optimal mix of 4% volcanic ash + 4% sugarcane bagasse ash is equal to 13.91%.

Heterogeneous oxidation of mercury in simulated post combustion conditions

Energy Technology Data Exchange (ETDEWEB)

Glenn A. Norton; Hongqun Yang; Robert C. Brown; Dennis L. Laudal; Grant E. Dunham; John Erjavec [Iowa State University, Ames, IA (United States). Center for Sustainable Environmental Technologies

2003-01-01

Heterogeneous mercury oxidation was studied by exposing whole fly ash samples and magnetic, nonmagnetic, and size-classified fly ash fractions to elemental mercury vapor in simulated flue gas streams. Fly ash from sub-bituminous Wyodak-Anderson PRB coal and bituminous Blacksville coal were used. Scanning electron microscopy, X-ray diffraction, thermogravimetric analyses, and BET N{sub 2} isothermal sorption analyses were performed to characterize the fly ash samples. Mercury speciation downstream from the ash was determined using the Ontario Hydro method. Results showed that the presence of fly ash was critical for mercury oxidation, and the surface area of the ash appears to be an important parameter. However, for a given fly ash, there were generally no major differences in catalytic oxidation potential between different fly ash fractions. This includes fractions enriched in unburned carbon and iron oxides. The presence of NO{sub 2}, HCl, and SO{sub 2} resulted in greater levels of mercury oxidation, while NO inhibited mercury oxidation. The gas matrix affected mercury oxidation more than the fly ash composition. 21 refs., 10 figs., 2 tabs.

The effect of low-NOx combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

DEFF Research Database (Denmark)

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

2010-01-01

been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NOx formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash......Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NOx combustion technologies. In this work, pulverized fuel has...... by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA...

Influence of fly ash added to a ceramic body on its thermophysical properties

Directory of Open Access Journals (Sweden)

Kováč Jozef

2016-01-01

Full Text Available We study thermal expansion, mass changes, heat capacity, and thermal diffusivity and conductivity for a ceramic body with 20 mass% and without fly ash content, using the TDA, TG, DTA, DSC, and flash method. The measurements were performed (a for green samples either isothermally or by a linear heating up to a temperature 600°C, 1050°C, or 1100°C, depending on the measurement method; (b at the room temperature for samples preheated at 100°C, 200°C, ..., 1100°C. In case (a addition of fly ash changes the final contraction only above ~900°C, while the thermal properties remain almost unchanged. In case (b the final contraction of samples at 1100°C is the same. The thermal diffusivity is nearly identical up to 700°C, and fly ash causes the diffusivity to stay almost constant up to 1000°C.

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

Geochemistry of Coal Ash in the Equatorial Wet Disposal System Environment

OpenAIRE

Kolay P. K.; Singh H.

2013-01-01

The coal utilization in thermal power plants in Malaysia has increased significantly which produces an enormous amount of coal combustion by-product (CCBP) or coal ash and poses severe disposal problem. As each coal ash is distinct, this study presents the geochemistry of the coal ash, in particular fly ash, produced from the combustion of local coal from Kuching Sarawak, Malaysia. The geochemical composition of the ash showed a high amount of silica, alumina, iron oxides and alkalies which w...

Fundamental study of ash formation and deposition: Effect of reducing stoichiometry

Energy Technology Data Exchange (ETDEWEB)

Helble, J.J.; Bool, L.E.; Kang, S.G. [and others

1995-11-01

This project is designed to examine the effects of combustion stoichiometry on the fundamental aspects of ash formation and ash deposit initiation. Emphasis is being placed on reducing stoichiometries associated with low-NOx combustion, although a range of oxidant/fuel ratios are being considered. Previous work has demonstrated that ash formation depends strongly upon coal mineralogy, including mineral type, size, amount, and the presence of organically associated inorganic species. Combustion temperature and the oxidation state of iron also play a significant role. As these latter items will vary with changes in stoichiometry, research to determine the net effect on deposition is required.

Geopolymer obtained from coal ash

International Nuclear Information System (INIS)

Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M.

2011-01-01

Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

An attempt to evaluate some regression models used for radiometric ash determination in the brown coal

International Nuclear Information System (INIS)

Karamuz, S.; Urbanski, P.; Antoniak, W.; Wagner, D.

1984-01-01

Five different regression models for determination of the ash as well as iron and calcium contents in brown coal using fluorescence and scattering of X-rays have been evaluated. Calculations were done using experimental results obtained from the natural brown coal samples to which appropriate quantities of iron, calcium and silicon oxides were added. The secondary radiation was excited by Pu-238 source and detected by X-ray argone filled proportional counter. The investigation has shown the superiority of the multiparametric models over the radiometric ash determination in the pit-coal applying aluminium filter for the correction of the influence of iron content on the intensity of scattered radiation. Standard error of estimation for the best algorithm is about three time smaler than that for algorithm simulating application of the aluminium filter. Statistical parameters of the considered algorithm were reviewed and discussed. (author)

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.

The influence of using volcanic ash and lime ash as filler on compressive strength in self compacting concrete

Science.gov (United States)

Karolina, Rahmi; Panatap Simanjuntak, Murydrischy

2018-03-01

Self Compacting Concrete (SCC) is a technology which is developing today in which concrete solidifies by itself without using vibrator. Casting conventional concrete which has a lot of reinforcement bars sometimes finds difficulty in achieving optimal solidity. The method used to solve this problem is by using SCC technology. SCC was made by using filler, volcanic ash, and lime ash as the filling materials so that the concrete became more solid and hollow space could be filled up. The variation of using these two materials was 10%, 15%, 20%, and 25% of the cementitious mass and using 1% of superplasticizer from cementitious material. The supporting testing was done by using the test when the concrete was still fluid and when it was solid. Malleable concrete was tested by using EFNARC 2002 standard in slump flow test, v-funnel test, l-shaped box test, and j-ring test to obtain filling ability and passing ability. In this malleable lime concrete test, there was the decrease, compared with normal SCC concrete without adding volcanic ash and lime ash. Testing was also done in solid concrete in compressive strength, tensile strength, and concrete absorption. The result of the testing showed that the optimum tensile strength in Variation 1, without volcanic ash and lime ash – with 1% of superplasticizer was 39.556 MPa, the optimum tensile strength in Variation 1, without volcanic ash and lime ash- with 1% of super-plasticizer was 3.563 MPa, while the value of optimum absorption which occurred in Variation 5 (25% of volcanic ash + 25% of lime ash + 50% of cement + 1% of superplasticizer) was 1.313%. This was caused by the addition of volcanic ash and lime ash which had high water absorption.

Electrocatalysis of the oxidations of some organic compounds on noble-metal electrodes by foreign-metal ad-atoms

International Nuclear Information System (INIS)

Tsang, R.W.

1981-10-01

Electrochemical oxidation of formic acid was studied on Pt electrodes in acid, and that of dextrose was studied on Pt and Au in alkali. Poisoning was observed on Pt but not on Au. Several heavy-metal ad-atoms (Pb, Bi, Tl) enhance greatly the anodic currents on Pt, while transition metals (Cu, Zn) inhibit the oxidation on Pt. The enhancement effect of the metal ad-atoms is correlated with electron structure. All metal ad-atoms showed an inhibitory effect on Au. Amperometry showed that Pt electrodes are completely deactivated within 10 s during dextrose oxidation without ad-atoms, while Au retains much of its activity even after 10 min. Ad-atoms maintains the Pt activity over much more than 10 s. 50 figures, 38 tables

Use of wood ash for road stabilisation

International Nuclear Information System (INIS)

Lagerkvist, A.; Lind, B.

2009-01-01

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

Superior photocatalytic, electrocatalytic, and self-cleaning applications of Fly ash supported ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Thirumalai, Kuppulingam; Balachandran, Subramanian [Department of Chemistry, Annamalai University, Annamalainagar, 608 002, Tamil Nadu (India); Swaminathan, Meenakshisundaram, E-mail: chemres50@gmail.com [Department of Chemistry, Annamalai University, Annamalainagar, 608 002, Tamil Nadu (India); Nanomaterials Laboratory, International Research Centre, Kalasalingam Universty, Krihnankoil, 626126 (India)

2016-11-01

Ever growing research on modified semiconductor oxides made a significant progress in catalytic functional materials. In this article, we report the modification of ZnO photocatalyst by a simple hydrothermal decomposition method utilizing the cheaply available industrial waste fly ash. This modified Fly ash-ZnO photocatalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM), Atomic force microscopy (AFM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). The XRD pattern indicates the presence of fly ash components and the hexagonal wurtzite structured ZnO. TEM images reveal well defined nanorod like structure. Reduction of photoluminescence intensity of Fly ash-ZnO at 418 nm, when compared to, prepared ZnO, indicates the suppression of recombination of the photogenerated electron–hole pair by loaded Fly ash on ZnO. Fly ash-ZnO exhibits enhanced photocatalytic activity for the degradation of azo dyes Reactive Orange 4, Rhodamine-B and Trypan Blue. This catalyst shows higher electrocatalytic activity than ZnO in the oxidation of methanol. Significant hydrophobicity of Fly ash-ZnO reveals its self cleaning property. - Highlights: • The degradation efficiency of Fly ash-ZnO under UV and Solar irradiation is greater than prepared ZnO and TiO{sub 2}‒P25. • Electrocatalytic activity of Fly ash-ZnO exhibits enhanced current production by methanol oxidation. • Fly ash-ZnO shows the high hydrophobicity than ZnO, it can be used as a self cleaning material for industrial applications.

Production of coloured glass-ceramics from incinerator ash using thermal plasma technology.

Science.gov (United States)

Cheng, T W; Huang, M Z; Tzeng, C C; Cheng, K B; Ueng, T H

2007-08-01

Incineration is a major treatment process for municipal solid waste in Taiwan. It is estimated that over 1.5 Mt of incinerator ash are produced annually. This study proposes using thermal plasma technology to treat incinerator ash. Sintered glass-ceramics were produced using quenched vitrified slag with colouring agents added. The experimental results showed that the major crystalline phases developed in the sintered glass-ceramics were gehlenite and wollastonite, but many other secondary phases also appeared depending on the colouring agents added. The physical/mechanical properties, chemical resistance and toxicity characteristic leaching procedure of the coloured glass-ceramics were satisfactory. The glass-ceramic products obtained from incinerator ash treated with thermal plasma technology have great potential for building applications.

Recoverable immobilization of transuranic elements in sulfate ash

Science.gov (United States)

Greenhalgh, Wilbur O.

1985-01-01

Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

The optimum content of rubber ash in concrete: flexural strength

Science.gov (United States)

Senin, M. S.; Shahidan, S.; Shamsuddin, S. M.; Ariffin, S. F. A.; Othman, N. H.; Rahman, R.; Khalid, F. S.; Nazri, F. M.

2017-11-01

Discarded scrap tyres have become one of the major environmental problems nowadays. Several studies have been carried out to reuse waste tires as an additive or sand replacement in concrete with appropriate percentages of tire rubber, called as rubberized concrete to solve this problem. The main objectives of this study are to investigate the flexural strength performance of concrete when adding the rubber ash and also to analyse the optimum content of rubber ash in concrete prisms. The performance total of 30 number of concrete prisms in size of 100mm x 100mm x 500 mm were investigated, by partially replacement of rubber ash with percentage of 0%, 3%, 5%, 7% and 9% from the volume of the sand. The flexural strength is increased when percentage of rubber ash is added 3% from control concrete prism, RA 0 for both concrete prism age, 7 days and 28 days with value 1.21% and 0.976% respectively. However, for RA 5, RA 7 and RA 9, the flexural strength was decreased compared to the control for both age, 7 days and 28 days. In conclusion, 3% is the optimum content of rubber ash in concrete prism for both concrete age

Beneficial use of CFB ash in pavement construction applications

Energy Technology Data Exchange (ETDEWEB)

N. Mike Jackson; Scott Schultz; Paul Sander; Lindsay Schopp [Jackson Research Engineers, Inc., Ponte Vedra Beach, FL (United States)

2009-07-15

The disposal of ash produced from the combustion of solid fuels has been a major subject of research and product development for many years. An innovative application has recently been employed by JEA to recycle both the bottom ash and fly ash from two new circulating fluidized bed (CFB) boilers as a stabilizer for local sandy soils and pavement base course material. The results of laboratory testing and field applications in the north Florida market area illustrate how this by-product is adding value in pavement and roadway construction applications. 14 refs., 2 figs., 10 tabs.

COMPARATIVE ASSESSMENT OF RICE HUSK ASH, POWDERED GLASS AND CEMENT AS LATERITIC SOIL STABILIZERS

Directory of Open Access Journals (Sweden)

Adebisi Ridwan

2016-10-01

Full Text Available This paper compares the stabilizing effects of three different materials, namely: rice husk ash, powdered glass, and cement on the properties of lateritic soil. The basic properties of the lateritic soil were first obtained through colour, moisture content determination, specific gravity, particle size distribution and Atterberg limits tests. Each of the stabilizing materials was then mixed with the lateritic soil in varying percentages of 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by weight of the soil. Thereafter, compaction and California bearing ratio (CBR tests were carried out on the sample mixes to determine the effects of the materials on the lateritic soil. Chemical tests were also carried out on the samples to determine their percentage oxides composition. The compaction test showed that the highest maximum dry densities (MDD obtained for the mixed samples were 2.32 g/cm3 (at 2.5% cement addition, 2.28g/cm3 (at 5% powdered glass (PG addition and 2.18 g/cm3 (at 5% rice husk ash (RHA addition with corresponding optimum moisture contents (OMC of 10.06%, 14.3% and 12.31% respectively. The CBR tests showed that the CBR values increased in all cases as the materials were added with those of the cement and powdered glass giving the highest values and showing close semblance under unsoaked conditions. The chemical test showed that the significant oxides present in the cement, powdered glass and rice husk ash were CaO (53.60%, SiO2 (68.45% and SiO2 (89.84% respectively.

Fabrication of CuO-doped catalytic material containing zeolite synthesized from red mud and rice husk ash for CO oxidation

Science.gov (United States)

Hieu Do Thi, Minh; Thinh Tran, Quoc; Nguyen, Tri; Van Nguyen Thi, Thuy; Huynh, Ky Phuong Ha

2018-06-01

In this study a series of the CuO-doped materials containing zeolite with varying CuO contents were synthesized from red mud (RM) and rice husk ash (RHA). The rice husk ash/red mud with the molar ratio of , and being 1.8, 2.5 and 60, respectively, were maintained during the synthetic process of materials. The characteristic structure samples were analyzed by x-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET) surface area and H2 temperature program reduction (H2-TPR). The catalytic activity of samples was evaluated in CO oxidation reaction in a microflow reactor at temperature range 200 °C–350 °C. The obtained results showed that all synthetic samples there exist the A-type zeolites with the average crystal size of 15–20 nm, the specific surface area of , and pore volume of . The material synthesized from RM and RHA with the zeolite structure (ZRM, undoped CuO) could also oxidize CO completely at 350 °C, and its activity was increase significantly when doped with CuO. CuO-doped materials with the zeolite structure exhibited excellent catalytic activity in CO oxidation. The ZRM sample loading 5 wt% CuO with particle nanosize about 10–30 nm was the best one for CO oxidation with complete conversion temperature at 275 °C.

Producing zeolites from fly ash

International Nuclear Information System (INIS)

Rayalu, S.; Labhestwar, N.K.; Biniwale, R.B.; Udhoji, J.S.; Meshram, S.U.; Khanna, P.

1998-01-01

Fly ash has virtually become a menace of thermal power generation, leading to its devastating effects on the environment. Development of alternate methods of its disposal - especially those with recourse to recovery of valuable materials-has thus become imperative. This paper deals with the utilisation of fly ash for the production of high value-added products, viz., commercial grade zeolites. The physico-chemical and morphological characteristics of fly ash based Zeolite-A (FAZ-A) compares well with commercial Zeolite-A. High calcium binding capacity, appropriate particle/pore size and other detergency characteristics of FAZ-A brings forth its potential as a substitute for phosphatic detergent builder. The technology is extremely versatile, and other products like Zeolite-X, Zeolite-Y, sodalite and mordenite are also amenable for cost effective production with modifications in certain reaction parameters. Low temperature operations, ready availability of major raw materials, simplicity of process and recycling of unused reactants and process water are special features of the process. (author)

Removal of Copper (II Ions in Aqueous Solutions by Sorption onto Alkali Activated Fly Ash

Directory of Open Access Journals (Sweden)

Darmayanti Lita

2018-01-01

Full Text Available Fly ash is a particulate material produced from coal combustion power plants with major components are silica, alumina, iron oxide, calcium oxide, magnesium oxide, and carbon which are ideal for metal adsorbents. The potential use of fly ash in the wastewater treatment process is obvious because it can be obtained cheaply in large quatities and it can be used as an adsorbent. However, fly ash still shows lower adsorption capacity unless it is activated. In this study, fly ash activated by NaOH 14 M and KOH 14 M solutions. The batch experiments were carried out to study the sorption of copper ions from aqueous on alkali activated fly ash. The influence of initial concentration and contact time were examined at constant pH and dose of adsorbent. The sorption capacity of copper ions increased with the initial concentration and contact time. The sorption capacities followed the order Na1>Ka1>FA. The adsorption isotherm model exhibited that the Langmuir model is very suitable with copper ions adsorption onto fly ash and alkali activated fly ash. Kinetic study shows that adsorption of copper ions onto FA, Na1, and Ka1 follows the pseudo second-order kinetics.

Assessing fly ash treatment: remediation and stabilization of heavy metals.

Science.gov (United States)

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

2012-03-01

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

Assessing fly ash treatment: Remediation and stabilization of heavy metals

KAUST Repository

Lima, A.T.

2010-12-17

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

Assessing fly ash treatment: Remediation and stabilization of heavy metals

KAUST Repository

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

2010-01-01

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

Investigation of rye straw ash sintering characteristics and the effect of additives

International Nuclear Information System (INIS)

Wang, Liang; Skreiberg, Øyvind; Becidan, Michael; Li, Hailong

2016-01-01

, the chemical reactions and physical restraining effects arose by calcite addition contributed to reduction of ash melts and sintering degree. Upon addition of kaolin, compositions of rye straw ash shifted from low temperature melting K–silicates to high temperature melting K–Al–silicates. The changes of ash chemistry were favorable for reducing sintering of the rye straw ash. As the Ca-sludge was added, reduction of sintering of the rye straw ash was less pronounced. Only K_4CaSi_3O_9 and a small amount of KCaPO_4 were identified in the rye straw ash as Ca-sludge was added.

CoSix contact resistance after etching and ashing plasma exposure

International Nuclear Information System (INIS)

Katahira, Ken; Fukasawa, Masanaga; Kobayashi, Shoji; Takizawa, Toshifumi; Isobe, Michio; Hamaguchi, Satoshi; Nagahata, Kazunori; Tatsumi, Tetsuya

2009-01-01

The authors investigated the contact resistance fluctuation caused by CoSi x damage in plasma etching and ashing processes. They found that CoSi x layers damaged by plasma process exposure are readily oxidized when exposed to air resulting in increased resistance. They also found that the contact resistance increases more when CH 3 F is used instead of CF 4 during etching process. The lower the mass number of dominant ions becomes, the deeper the ions penetrate. Molecular dynamics simulation revealed that dissociated species from lighter ions penetrate deeper and that this stimulates deeper oxidation. They also found that contact resistance further increased by using postetch ashing plasma even in an H 2 /N 2 ashing process in which O 2 was not used. Here, too, the reason for this is that the ion penetration causes deep oxidation. They observed that the contact resistance has a linear relationship with the oxide concentration in CoSi x . This leads to the conclusion that it is essential to precisely control the ion energy as well as to properly select the ion species in the plasma process in the fabrication of next-generation semiconductor devices.

A study on the improvement of oxidation resistance of OAE-added stainless steels for high temperature applications

International Nuclear Information System (INIS)

Kim, Dae Hwan; Kim, Gil Moo

1996-01-01

Since the manufacturing temperature of stainless steels is relatively high, oxidation at the elevated temperature becomes important. The chemical and physical properties of the protective oxide film which was formed on the stainless steels at high temperature for the oxidation resistance are important in determining the rate of oxidation and the life of equipment exposed to high temperature oxidizing environments. In this study, the oxidation behavior of STS 309S and STS 409L added by a small amount of oxygen active element(each + 0.5wt% Hf and Y) was studied to improve oxidation resistance. In the cyclic oxidation, while OAE-free specimens showed relatively poor oxidation resistance due to spallations and cracks of Cr-rich oxide layer, OAE-added specimens improved cyclic oxidation resistance assumably due to constant oxidation rate with stable oxide layers at high temperature. Especially Hf improved cyclic oxidation resistance by forming Cr-rich oxide layer preventing internal oxidation in STS 309S. (author)

Ash from a pulp mill boiler--characterisation and vitrification.

Science.gov (United States)

Ribeiro, Ana S M; Monteiro, Regina C C; Davim, Erika J R; Fernandes, M Helena V

2010-07-15

The physical, chemical and mineralogical characterisation of the ash resulting from a pulp mill boiler was performed in order to investigate the valorisation of this waste material through the production of added-value glassy materials. The ash had a particle size distribution in the range 0.06-53 microm, and a high amount of SiO(2) (approximately 82 wt%), which was present as quartz. To favour the vitrification of the ash and to obtain a melt with an adequate viscosity to cast into a mould, different amounts of Na(2)O were added to act as fluxing agent. A batch with 80 wt% waste load melted at 1350 degrees C resulting in a homogeneous transparent green-coloured glass with good workability. The characterisation of the produced glass by differential thermal analysis and dilatometry showed that this glass presents a stable thermal behaviour. Standard leaching tests revealed that the concentration of heavy metals in the leaching solution was lower than those allowed by the Normative. As a conclusion, by vitrification of batch compositions with adequate waste load and additive content it is possible to produce an ash-based glass that may be used in similar applications as a conventional silicate glass inclusively as a building ecomaterial. 2010 Elsevier B.V. All rights reserved.

Influence of fly-ashes on properties of ordinary concretes

Directory of Open Access Journals (Sweden)

Rutkowska Gabriela

2016-03-01

Full Text Available Influence of fly-ashes on properties of ordinary concretes. Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. The construction and building materials industry has the greatest potential for reuse of waste. The article presents the results of investigations of selected properties (consistency, water absorbability, compressive strength and tensile strength after 28 and 56 days of curing, depth of penetration of ordinary concretes and concretes containing fly-ashes - calcareous and siliceous ash − in their composition. To make the samples, the Portland cement CEM I 42.5 R and natural aggregate with graining of 0-16 mm were used. The concrete with siliceous and calcareous admixtures was made in three lots where the ash was added in the quantity of 15, 20 and 30% of the cement mass. After the tests, it was stated that the fly-ash admixture does not increase the air content in the mix, it increases the compressive strength in time and the siliceous ash improves the splitting tensile strength.

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

The durability of fired brick incorporating textile factory waste ash and basaltic pumice

Energy Technology Data Exchange (ETDEWEB)

Binici, Hanifi [Kahramanmaras Sutcu Imam Univ., Kahramanmaras (Turkey). Dept. of Civil Engineering; Yardim, Yavuz [Epoka Univ., Tirana (Albania). Dept. of Civil Engineering

2012-07-15

This study investigates the durability of fired brick produced with additives of textile factories' waste ash and basaltic pumice. The effects of incorporating waste ash and basaltic pumice on durability and mechanical properties of the clay bricks were studied. Samples were produced with different ratios of the textile factories' waste ash and basaltic pumice added and at different fire temperatures of 700, 900, and 1 050 C for 8 h. The bricks with additives were produced by adding equal amounts of textile factories' waste ash and basaltic pumice, separately and together, with rates of 5, 10 and 20 wt.%. The produced samples were kept one year in sodium sulphate and sodium nitrate and tested under freezing - unfreezing and drying - wetting conditions. Then compression strength and mass loss of the samples with and without additives were investigated. The test results were compared with standards and results obtained from control specimens. The results showed that incorporations up to 10 wt.% of textile factories' waste ash and basaltic pumice is beneficial to the fired brick. Both textile factories' waste ash and basaltic pumice were suitable additives and could be used for more durable clay brick production at 900 C fire temperature. (orig.)

Glass Ceramics Composites Fabricated from Coal Fly Ash and Waste Glass

International Nuclear Information System (INIS)

Angjusheva, B.; Jovanov, V.; Srebrenkoska, V.; Fidancevska, E.

2014-01-01

Great quantities of coal ash are produced in thermal power plants which present a double problem to the society: economical and environmental. This waste is a result of burning of coal at temperatures between 1100-14500C. Fly ash available as fine powder presents a source of important oxides SiO2, Al2O3, Fe2O3, MgO, Na2O, but also consist of small amount of ecologically hazardous oxides such as Cr2O3, NiO, MnO. The combination of the fly ash with waste glass under controlled sintering procedure gave bulk glass-ceramics composite material. The principle of this procedure is presented as a multi barrier concept. Many researches have been conducted the investigations for utilization of fly ash as starting material for various glass–ceramics production. Using waste glass ecologically hazardous components are fixed at the molecular level in the silicate phase and the fabricated new glass-ceramic composites possess significantly higher mechanical properties. The aim of this investigation was to fabricate dense glass ceramic composites using fly ash and waste glass with the potential for its utilization as building material

Pore Structure Characterization in Concrete Prepared with Carbonated Fly Ash

Science.gov (United States)

Sahoo, Sanjukta

2018-03-01

Carbon dioxide capture and storage (CCS) is a technique to address the global concern of continuously rising CO2 level in the atmosphere. Fly ash is considered as a suitable medium for CCS due to presence of metal oxides. The fly ash which has already sequestered carbon dioxide is referred to as carbonated fly ash. Recent research reveals better durability of concretes using carbonated fly ash as part replacement of cement. In the present research pore structure characterization of the carbonated fly ash concrete has been carried out. Mercury Intrusion porosimetry test has been conducted on control concrete and concrete specimens using fly ash and carbonated fly ash at replacement levels of 25% and 40%. The specimens have been water cured for 28 days and 90 days. It is observed that porosity reduction rate is more pronounced in carbonated fly ash concrete compared to control concrete at higher water curing age. Correlation analysis is also carried out which indicates moderately linear relationship between porosity % and pore distribution with particle size and water curing.

Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations.

Science.gov (United States)

Rigsby, C M; Showalter, D N; Herms, D A; Koch, J L; Bonello, P; Cipollini, D

2015-07-01

Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash hosts, and quantified the activity and production of selected detoxification, digestive, and antioxidant enzymes. We hypothesized that differences in larval physiology could be used to infer resistance mechanisms of ash. We found no differences in cytochrome P450, glutathione-S-transferase, carboxylesterase, sulfotransferase, and tryptic BApNAase activities between larvae feeding on different hosts. Despite this, Manchurian ash-fed larvae produced a single isozyme of low electrophoretic mobility that was not produced in white or green ash-fed larvae. Additionally, larvae feeding on white and green ash produced two serine protease isozymes of high electrophoretic mobility that were not observed in Manchurian ash-fed larvae. We also found lower activity of β-glucosidase and higher activities of monoamine oxidase, ortho-quinone reductase, catalase, superoxide dismutase, and glutathione reductase in Manchurian ash-fed larvae compared to larvae that had fed on susceptible ash. A single isozyme was detected for both catalase and superoxide dismutase in all larval groups. The activities of the quinone-protective and antioxidant enzymes are consistent with the resistance phenotype of the host species, with the highest activities measured in larvae feeding on resistant Manchurian ash. We conclude that larvae feeding on Manchurian ash could be under quinone and oxidative stress, suggesting these may be potential mechanisms of resistance of Manchurian ash to EAB larvae, and that quinone-protective and antioxidant enzymes are important counter-adaptations of larvae for dealing with these resistance

Characterization of ashes of elephant grass (Pennisetum purpureum) for potential added in mass red ceramic

International Nuclear Information System (INIS)

Silva, A.M.F.D.; Sales, K.A.; Monteiro, S.N.; Vieira, C.M.F.

2012-01-01

This work is in characterizing ash from biomass grass (Pennisetum purpureums) for incorporation into red ceramic masses. The ashes of elephant grass were generated from burning this dry biomass in an industrial furnace of red ceramic. The morphology of the material generated was observed by an optical microscope. The chemical composition was determined by fluorescence X-ray spectrometry, and the identification of phases by X-ray diffraction. The particle size distribution was obtained by sieving. Thermogravimetric analyzes were also conducted. The results indicate that these ashes are constituted of high quantities of SiO 2 , MgO, CaO and K 2 O, totaling approximately 75% of composition of matter. They have a particle size of 0.7 to 2.2mm featuring. The residue as a kind of coarse particles. Therefore, the results of this study can support future research to the addition of this residue in structural ceramics products (red ceramic)

Ultrafine ash aerosols from coal combustion: Characterization and health effects

Energy Technology Data Exchange (ETDEWEB)

William P. Linak; Jong-Ik Yoo; Shirley J. Wasson; Weiyan Zhu; Jost O.L. Wendt; Frank E. Huggins; Yuanzhi Chen; Naresh Shah; Gerald P. Huffman; M. Ian Gilmour [US Environmental Protection Agency, Research Triangle Park, NC (United States). National Risk Management Research Laboratory

2007-07-01

Ultrafine coal fly-ash particles withdiameters less than 0.5 {mu}m typically comprise less than 1% of the total fly-ash mass. This paper reports research focused on both characterization and health effects of primary ultrafine coal ash aerosols alone. Ultrafine, fine, and coarse ash particles were segregated and collected from a coal burned in a 20 kW laboratory combustor and two additional coals burned in an externally heated drop tube furnace. Extracted samples from both combustors were characterized by transmission electron microscopy (TEM), wavelength dispersive X-ray fluorescence(WD-XRF) spectroscopy, Moessbauer spectroscopy, and X-ray absorption fine structure (XAFS) spectroscopy. Pulmonary inflammation was characterized by albumin concentrations in mouse lung lavage fluid after instillation of collected particles in saline solutions and a single direct inhalation exposure. Results indicate that coal ultrafine ash sometimes contains significant amounts of carbon, probably soot originating from coal tar volatiles, depending on coal type and combustion device. Surprisingly, XAFS results revealed the presence of chromium and thiophenic sulfur in the ultrafine ash particles. The instillation results suggested potential lung injury, the severity of which could be correlated with the carbon (soot) content of the ultrafines. This increased toxicity is consistent with theories in which the presence of carbon mediates transition metal (i.e., Fe) complexes, as revealed in this work by TEM and XAFS spectroscopy, promoting reactive oxygenspecies, oxidation-reduction cycling, and oxidative stress. 24 refs., 7 figs.

A method of eliminating the surface defect in low-temperature oxidation powder added UO2 pellet

International Nuclear Information System (INIS)

Yoo, H. S.; Lee, S. J.; Kim, J. I.; Jeon, K. R.; Kim, J. W.

2002-01-01

A study on methods to eliminate surface defect shown in low-temperature oxidation powder added UO 2 pellet has been performed. Powders oxidized at 350 .deg. C for 4 hrs were prepared and mixed with UO 2 powder after crushing them. After being sintered, surfaces of the pellet were inspected both visually and optically. A large number of defects were observed on the surface of the specimens in which low-temperature oxidation powders were directly mixed or master mixed with UO 2 powder while both specimens produced from mixed powders including milled oxidation powders and powders that were milled totally after mixing had clean surfaces. However, optical examination showed considerably large defected pores in the milled oxidation powder added pellet and it was confirmed that the inner defects can be eliminated completely only when milling the entire mixture on UO 2 and low-temperature oxidation powder, but not by crushing only oxidation powder

Activated Carbon-Fly Ash-Nanometal Oxide Composite Materials: Preparation, Characterization, and Tributyltin Removal Efficiency

Directory of Open Access Journals (Sweden)

Olushola S. Ayanda

2013-01-01

Full Text Available The physicochemical properties, nature, and morphology of composite materials involving activated carbon, fly ash, nFe3O4, nSiO2, and nZnO were investigated and compared. Nature and morphology characterizations were carried out by means of scanning electron and transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Other physicochemical characterizations undertaken were CNH analysis, ash content, pH, point of zero charge, and surface area and porosity determination by BET. Experimental results obtained revealed that activated carbon, nSiO2, activated carbon-fly ash, activated carbon-fly ash-nFe3O4, activated carbon-fly ash-nSiO2, and activated carbon-fly ash-nZnO composite materials exhibited net negative charge on their surfaces while fly ash, nFe3O4, and nZnO possessed net positive charge on their surfaces. Relatively higher removal efficiency (>99% of TBT was obtained for all the composite materials compared to their respective precursors except for activated carbon. These composite materials therefore offer great potential for the remediation of TBT in wastewaters.

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)

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

Science.gov (United States)

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-01-01

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability. PMID:28793518

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

Science.gov (United States)

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-08-21

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

Synthesis of ZSM-5 zeolite from coal fly ash and rice husk: characterization and application for partial oxidation of methane to methanol

Science.gov (United States)

Krisnandi, Y. K.; Yanti, F. M.; Murti, S. D. S.

2017-04-01

Indonesian fly ash (SiO2/Al2O3 mole ratio = 3.59) was used together with rice husk (SiO2 92%) as raw material for mesoporous ZSM-5 zeolite synthesis. Prior being used, coal fly ash and rice husk were subjected to pre-treatment in order to extract silicate (SiO4 4-) and aluminate (AlO4 5-) and to remove the impurities. Then the ZSM-5 zeolite were synthesized through hydrothermal treatment using two types of templates (TPAOH and PDDA). The as-synthesized ZSM-5 was characterized using FTIR, XRD, SEM-EDX, and BET. The result of FTIR showed peaks at 1250-950 cm-1 (v asymetric T-O), 820-650 cm-1 (v symetric T-O), and at 650-500 cm-1 confirming the presence of the five number ring of the pentasil structure. The result of XRD showed the appearance of certain peaks in the position 2 theta between 7-9° and 22-25° indicative of ZSM-5 structure, but also showed the pattern of low intensity magnetite and hematite. The SEM image showed the rough surface of hexagonal crystals from ZSM-5 structure, indicative of mesoporosity in the structure. EDX result showed Si/Al ratio of 20, while surface area analysis gave SA of 43.16. The ZSM-5 zeolites then was modified with cobalt oxide through impregnation method. The catalytic activity as heterogeneous catalysts in partial oxidation of methane was tested. The result showed that hence the catalytic activity of ZSM-5 and Co/ZSM-5 from fly ash and rice husk were still inferior compared to the pro-analysis sourced-counterpart, they were potential to be used as catalyst in the partial oxidation of methane to methanol.

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.

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.

Electrodialytic removal of heavy metals from MSWI fly ashes

Energy Technology Data Exchange (ETDEWEB)

Pedersen, A.J.; Ottosen, L.M.; Villumsen, A. [Dept. of Civil Engineering, Technical Univ. of Denmark, Lyngby (Denmark)

2001-07-01

In this work a method called electrodialytic remediation, which is a combination of electrokinetic remediation and electrodialysis, is used for the extraction of heavy metals from MSWI fly ashes. It is shown that the use of electric current enhances the metal desorption significantly compared to traditional, chemical extraction. The metals of concern are Cd, Pb, Zn, Cu and Cr. Addition of ammonium citrate to the ash before and during remediation enhances the desorption and removal rate of all the examined heavy metals (Cd, Pb, Zn, Cu and Cr) compared to experiments only added distilled water. By introducing continuous stirring of the ash slurry during electrodialytic remediation, it is shown that the remediation rate is improved significantly compared to 'traditional' electrodialytic remediation experiments. The development of the acidic front is avoided due to better pH-control, and a better contact between the ash particles and the liquid is achieved. Up to 62% of the initial Cd, 8.3% Pb, 73% Zn, 59% Cu, and 20% Cr has been removed from two different fly ashes in electrodialytic remediation experiments. (orig.)

Catalytic effect of lignite ash on steam gasification of oil sand coke

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; Palmer, A.

1986-06-16

Steam gasification of Suncor and Syncrude cokes was carried out in the presence of ash obtained after burning Onakawana lignite. Catalytic effects of the ash were evident at 930 C whereas at 830 C little effect was observed. These observations were attributed to the combined actions of Ca- and Fe-containing species in the ash, in which the former neutralized the sulfur in the cokes to prevent poisoning of Fe oxides. 5 tabs., 5 figs., 15 refs.

Characterization of sugarcane bagasse ash for use in ceramic bodies

Energy Technology Data Exchange (ETDEWEB)

Faria, K.C.P.; Gurgel, R.F.; Holanda, J.N.F., E-mail: katiacpf@terra.com.br, E-mail: rfguenf2009@hotmail.com, E-mail: holanda@uenf.br [Universidade Estadual do Norte Fluminense (LAMAV/GMCer/UENF), Campos dos Goytacazes-RJ (Brazil)

2009-07-01

The objective of this work is to characterization of sugarcane bagasse ash waste aiming the use it in red ceramic industry. The characterization was done in terms of chemical composition, X-ray diffraction, particle size distribution, morphology, and plasticity. The results show that the cane bagasse ash waste is a non plastic material, which contains high content of silica and minor amounts of Al, Fe, Ca, Mg, and K oxides. Thus, the sugar cane bagasse ash waste presents high potential for application in the manufacture of ceramic products such as bricks, roofing tiles, and ceramic tiles. (author)

Characterization of sugarcane bagasse ash for use in ceramic bodies

International Nuclear Information System (INIS)

Faria, K.C.P.; Gurgel, R.F.; Holanda, J.N.F.

2009-01-01

The objective of this work is to characterization of sugarcane bagasse ash waste aiming the use it in red ceramic industry. The characterization was done in terms of chemical composition, X-ray diffraction, particle size distribution, morphology, and plasticity. The results show that the cane bagasse ash waste is a non plastic material, which contains high content of silica and minor amounts of Al, Fe, Ca, Mg, and K oxides. Thus, the sugar cane bagasse ash waste presents high potential for application in the manufacture of ceramic products such as bricks, roofing tiles, and ceramic tiles. (author)

A comparative study on different burning method of sewage sludge ash in mortar brick with eggshell powder as additive

Science.gov (United States)

Ing, Doh Shu; Azed, Muhammad Aizat; Chin, Siew Choo

2017-11-01

Population growth that increase every year has led to the increasing amount of waste generated annually. The content of heavy metal Cadmium (Cd), Lead (Pb) and Zinc (Zn) represent the biggest concentrations of heavy metals in sewage sludge waste which can be the source of pollution. Furthermore, the excessive disposal of eggshells waste to landfills may attract rats and worms due to the organic protein matrix that may pose health problem to the public. In the last decade, the demand on cement mortar brick has increased has resulted in higher cement production. However, cement plant is one of the major contributors of carbon dioxide emission. Hence, this research focuses on the production of environmental friendly cement with sewage sludge since there is occurrence of pozolonic material in Sewage Sludge Ash (SSA). From the initial finding, the major components of SSA are Silicon Dioxide (SiO2), Calcium oxide (CaO), Aluminium Oxide (Al2O3), Iron (III) Oxide (Fe2O3), Sodium Oxide (Na2O), Potassium oxide (K2O), Magnesium Oxide (MgO) and Iron (II) Oxide (FeO). Sewage sludge needed to be incinerated to remove the heavy metal before it can be used as cement replacement in mortar brick production. The sewage sludge were treated using two methods namely incineration and microwave. Both types of sewage sludge were then added with eggshell powder as additive. Eggshell powder act as additive in this research due to its high content of calcium carbonate and has nearly same composition of limestone used in the production of cement. Different percentages of Eggshell Powder (ESP) (0%, 5%, 10%, 15%) and 10% fixed of Microwaved Sewage Sludge Ash (MSSA) and Incinerated Sewage Sludge Ash (ISSA) as optimum dosage partially replacing the cement used to test the brick mortar properties in term of compressive strength, flexural strength and also water absorption. Result showed that ISSA with 5% of ESP is the most optimum brick with highest compressive strength and flexural strength

Impact of response criteria (tibia ash weight vs. percent) on phytase relative non phytate phosphorus equivalance.

Science.gov (United States)

Li, W; Angel, R; Kim, S-W; Jiménez-Moreno, E; Proszkowiec-Weglarz, M; Plumstead, P W

2015-09-01

The current study was conducted to evaluate the impacts of using tibia ash percentage or ash weight as the response criteria on estimated phytase relative equivalence. Straight run broilers were fed treatment (Trt) diets from 7 to 21 d age (6 birds/pen, 8 pens/Trt). The corn-soy based Trt were formulated to contain 0.80% Ca and 4 non-phytate phosphorus (nPP) concentrations (0.20, 0.27, 0.34, and 0.40%). Monocalcium phosphate was the inorganic phosphate source added to achieve 4 different dietary nPP concentrations and against which the nPP relative equivalence of phytase was determined. A 6-phytase (Danisco Animal Nutrition, DuPont Industrial Biosciences, Marlborough, UK) was added at 500 or 1,000 phytase unit ( FTU: )/kg to the 0.20% nPP diet resulting 6 total Trts. Tibia ash was determined at 21 d age. Phytase fed at 500 or 1,000 FTU/kg increased tibia ash weight and ash percentage compared to that of birds fed 0.20% nPP diet without phytase (Pphytase nPP relative equivalence. The R2 obtained from pen value regressions were 0.81 and 0.84, for tibia ash weight and percentage, respectively. Ash percentage from birds fed 500 and 1,000 FTU phytase/kg fell within the range obtained with the MCP additions. Ash weight (842 mg/tibia) from birds fed 1,000 FTU phytase/kg exceeded (Pphytase/kg Trt. The nPP relative equivalence in birds fed 500 FTU phytase/kg were 0.117 and 0.168% based on ash percentage and weight, respectively (Pphytase/kg was 0.166% for ash percentage. Results suggested that ash weight better reflects the amount of bone mineralization as compared to ash percentage and using ash percentage may lead to an underestimation of phytase efficacy. © 2015 Poultry Science Association Inc.

Phytosterol oxidation products (POP) in foods with added phytosterols and estimation of their daily intake: A literature review.

Science.gov (United States)

Lin, Yuguang; Knol, Diny; Trautwein, Elke A

2016-10-01

1To evaluate the content of phytosterol oxidation products (POP) of foods with added phytosterols, in total 14 studies measuring POP contents of foods with added phytosterols were systematically reviewed. In non-heated or stored foods, POP contents were low, ranging from (medians) 0.03-3.6 mg/100 g with corresponding oxidation rates of phytosterols (ORP) of 0.03-0.06%. In fat-based foods with 8% of added free plant sterols (FPS), plant sterol esters (PSE) or plant stanol esters (PAE) pan-fried at 160-200°C for 5-10 min, median POP contents were 72.0, 38.1, and 4.9 mg/100 g, respectively, with a median ORP of 0.90, 0.48, and 0.06%. Hence resistance to thermal oxidation was in the order of PAE > PSE > FPS. POP formation was highest in enriched butter followed by margarine and rapeseed oil. In margarines with 7.5-10.5% added PSE oven-heated at 140-200°C for 5-30 min, median POP content was 0.3 mg/100 g. Further heating under same temperature conditions but for 60-120 min markedly increased POP formation to 384.3 mg/100 g. Estimated daily upper POP intake was 47.7 mg/d (equivalent to 0.69 mg/kg BW/d) for foods with added PSE and 78.3 mg/d (equivalent to 1.12 mg/kg BW/d) for foods with added FPS as calculated by multiplying the advised upper daily phytosterol intake of 3 g/d with the 90% quantile values of ORP. In conclusion, heating temperature and time, chemical form of phytosterols added and the food matrix are determinants of POP formation in foods with added phytosterols, leading to an increase in POP contents. Practical applications: Phytosterol oxidation products (POP) are formed in foods containing phytosterols especially when exposed to heat treatment. This review summarising POP contents in foods with added phytosterols in their free and esterified forms reveals that heating temperature and time, the chemical form of phytosterols added and the food matrix itself are determinants of POP formation with heating

Performance of diesel particulate filter catalysts in the presence of biodiesel ash species

DEFF Research Database (Denmark)

Hansen, Brian Brun; Jensen, Anker Degn; Jensen, Peter Arendt

2013-01-01

The utilization of bio-fuels, such as biodiesel, is expected to contribute significantly towards the planned 10% of renewable energy within the EU transport sector by 2020. Increased biodiesel blend percentages may change engine exit flue gas ash composition and affect the long-term performance...... of cleaning technologies, such as oxidation catalysts and diesel particulate filters. In this work the performance of a commercial catalyst has been studied for conversion of diesel particulate matter (SRM 2975) at 10% O2, in the presence of salts simulating ash species derived from engine oil and biodiesel...... the temperature at which the oxidation rate peaked from 662 ± 1 °C to 526 ± 19 °C. The introduction of biodiesel ash species such as Na2CO3, K2CO3 or K3PO4 decreased the peak conversion temperature further (422 ± 12; 404 ± 4 and 423 ± 7 °C), with a limited dependence on ash concentration. A deterioration...

Lipid peroxidation and cytotoxicity induced by respirable volcanic ash

Energy Technology Data Exchange (ETDEWEB)

Cervini-Silva, Javiera, E-mail: jcervini@correo.cua.uam.mx [Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana Unidad Cuajimalpa, México City (Mexico); Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Nieto-Camacho, Antonio [Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Gomez-Vidales, Virginia [Laboratorio de Resonancia Paramagnética Electrónica, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Ramirez-Apan, María Teresa [Laboratorio de Pruebas Biológicas, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City (Mexico); Palacios, Eduardo; Montoya, Ascención [Dirección de Investigación y Posgrado, Instituto Mexicano del Petróleo (Mexico); Kaufhold, Stephan [BGR Bundesansaltfür Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover (Germany); and others

2014-06-01

Highlights: • Respirable volcanic ash induces oxidative degradation of lipids in cell membranes. • Respirable volcanic ash triggers cytotoxicity in murin monocyle/macrophage cells. • Oxidative stress is surface controlled but not restricted by surface- Fe{sup 3+}. • Surface Fe{sup 3+} acts as a stronger inductor in allophanes vs phyllosilicates or oxides. • Registered cell-viability values were as low as 68.5 ± 6.7%. - Abstract: This paper reports that the main component of respirable volcanic ash, allophane, induces lipid peroxidation (LP), the oxidative degradation of lipids in cell membranes, and cytotoxicity in murin monocyle/macrophage cells. Naturally-occurring allophane collected from New Zealand, Japan, and Ecuador was studied. The quantification of LP was conducted using the Thiobarbituric Acid Reactive Substances (TBARS) assay. The cytotoxic effect was determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide colorimetric assay. Electron-Paramagnetic Resonance (EPR) determinations of naturally-occurring allophane confirmed the incorporation in the structure and clustering of structural Fe{sup 3+}, and nucleation and growth of small-sized Fe (oxyhydr)oxide or gibbsite. LP induced by allophane varied with time, and solid concentration and composition, reaching 6.7 ± 0.2 nmol TBARS mg prot{sup −1}. LP was surface controlled but not restricted by structural or surface-bound Fe{sup 3+}, because redox processes induced by soluble components other than perferryl iron. The reactivity of Fe{sup 3+} soluble species stemming from surface-bound Fe{sup 3+} or small-sized Fe{sup 3+} refractory minerals in allophane surpassed that of structural Fe{sup 3+} located in tetrahedral or octahedral sites of phyllosilicates or bulk iron oxides. Desferrioxamine B mesylate salt (DFOB) or ethylenediaminetetraacetic acid (EDTA) inhibited LP. EDTA acted as a more effective inhibitor, explained by multiple electron transfer pathways. Registered cell

Inhibition effect on lipid oxidation of irradiated pork by adding hawthorn flavonoid extract

International Nuclear Information System (INIS)

Wang Xiaoming; Liu Chao; Cao Lei; Li Kexi

2011-01-01

The antioxidant activity of hawthorn flavonoid extract and its inhibition effect on irradiated pork lipid oxidant were investigated. The results showed that hawthorn flavonoids had efficient scavenging effect on DPPH free radicals (DPPH ·), and the scavenging rate reached 56% while 2 ml of 0.035 mg/ml hawthorn flavonoid extract was added. Hawthorn flavonoid extract can inhibition the lipid oxidation of irradiated pork effectively and it showed a stronger inhibition ability while the hawthorn flavonoid extract were used together with Vc. It is concluded that can decrease the lipid oxidation of pork, hawthorn flavonoid extract is a remarkable natural antioxidant. (authors)

HYDRO-ABRASIVE RESISTANCE AND MECHANICAL PROPERTIES OF CONCRETE WITH ADDED FLY ASH

OpenAIRE

Ristić, Nenad; Grdić, Zoran; Topličić-Ćurčić, Gordana

2015-01-01

The durability of hydraulic engineering structures mostly depends on the resistance of their concrete surfaces to mechanical abrasion. In this paper, we study the hydro-abrasive resistance and mechanical properties of concrete in which cement is partially replaced with fly ash in various proportions. To evaluate these concretes, we measured their compressive strength, flexural strength, static modulus of elasticity, ultrasound velocity through concrete, and sclerometer rebound. The hydro-abra...

The secondary release of mercury in coal fly ash-based flue-gas mercury removal technology.

Science.gov (United States)

He, Jingfeng; Duan, Chenlong; Lei, Mingzhe; Zhu, Xuemei

2016-01-01

The secondary release of mercury from coal fly ash is a negative by-product from coal-fired power plants, and requires effective control to reduce environmental pollution. Analysing particle size distribution and composition of the coal fly ash produced by different mercury removing technologies indicates that the particles are generally less than 0.5 mm in size and are composed mainly of SiO2, Al2O3, and Fe2O3. The relationships between mercury concentration in the coal fly ash, its particle size, and loss of ignition were studied using different mercury removing approaches. The research indicates that the coal fly ash's mercury levels are significantly higher after injecting activated carbon or brominating activated carbon when compared to regular cooperating-pollution control technology. This is particularly true for particle size ranges of >0.125, 0.075-0.125, and 0.05-0.075 mm. Leaching experiments revealed the secondary release of mercury in discarded coal fly ash. The concentration of mercury in the coal fly ash increases as the quantity of injecting activated carbon or brominating activated carbon increases. The leached concentrations of mercury increase as the particle size of the coal fly ash increases. Therefore, the secondary release of mercury can be controlled by adding suitable activated carbon or brominating activated carbon when disposing of coal fly ash. Adding CaBr2 before coal combustion in the boiler also helps control the secondary release of mercury, by increasing the Hg(2+) concentration in the leachate. This work provides a theoretical foundation for controlling and removing mercury in coal fly ash disposal.

Incineration ash conditioning processes

International Nuclear Information System (INIS)

Jouan, A.; Ouvrier, N.; Teulon, F.

1990-01-01

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

Properties of Controlled Low Strength Material with Circulating Fluidized Bed Combustion Ash and Recycled Aggregates

Science.gov (United States)

Weng, Tsai-Lung; Cheng, An; Chao, Sao-Jeng; Hsu, Hui-Mi

2018-01-01

This study aims to investigate the effect of adding circulating fluidized bed combustion (CFBC) ash, desulfurization slag, air-cooled blast-furnace slag and coal bottom ash to the controlled low-strength material (CLSM). Test methods include slump flow test, ball drop test, water soluble chloride ion content measurement, compressive strength and length change measurement. The results show that (1) the use of CFBC hydration ash with desulfurization slag of slump flow is the best, and the use of CFBC hydration ash with coal bottom ash and slump flow is the worst; (2) CFBC hydration ash with desulfurization slag and chloride ion content is the highest; (3) 24 h ball drop test (diameter ≤ 76 mm), and test results are 70 mm to 76 mm; (4) CFBC hydration ash with desulfurization slag and compression strength is the highest, with the coal bottom ash being the lowest; increase of CFBC hydration ash can reduce compressive strength; and (5) the water-quenched blast furnace slag and CFBC hydration ash would expand, which results in length changes of CLSM specimens. PMID:29724055

CoSi{sub x} contact resistance after etching and ashing plasma exposure

Energy Technology Data Exchange (ETDEWEB)

Katahira, Ken; Fukasawa, Masanaga; Kobayashi, Shoji; Takizawa, Toshifumi; Isobe, Michio; Hamaguchi, Satoshi; Nagahata, Kazunori; Tatsumi, Tetsuya [Nagasaki Production Division 1, Sony Semiconductor Kyushu Corporation, 1883-43 Tsukuba-machi, Isahaya-shi, Nagasaki 854-0065 (Japan); Semiconductor Technology Development Division, Semiconductor Business Group, Sony Corporation, 4-14-1 Asahi-cho, Atsugi-shi, Kanagawa 243-0014 (Japan); Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Semiconductor Technology Development Division, Semiconductor Business Group, Sony Corporation, 4-14-1 Asahi-cho, Atsugi-shi, Kanagawa 243-0014 (Japan)

2009-07-15

The authors investigated the contact resistance fluctuation caused by CoSi{sub x} damage in plasma etching and ashing processes. They found that CoSi{sub x} layers damaged by plasma process exposure are readily oxidized when exposed to air resulting in increased resistance. They also found that the contact resistance increases more when CH{sub 3}F is used instead of CF{sub 4} during etching process. The lower the mass number of dominant ions becomes, the deeper the ions penetrate. Molecular dynamics simulation revealed that dissociated species from lighter ions penetrate deeper and that this stimulates deeper oxidation. They also found that contact resistance further increased by using postetch ashing plasma even in an H{sub 2}/N{sub 2} ashing process in which O{sub 2} was not used. Here, too, the reason for this is that the ion penetration causes deep oxidation. They observed that the contact resistance has a linear relationship with the oxide concentration in CoSi{sub x}. This leads to the conclusion that it is essential to precisely control the ion energy as well as to properly select the ion species in the plasma process in the fabrication of next-generation semiconductor devices.

Removal mechanism of phosphate from aqueous solution by fly ash.

Science.gov (United States)

Lu, S G; Bai, S Q; Zhu, L; Shan, H D

2009-01-15

This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

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....

Utilization of power plant bottom ash as aggregates in fiber-reinforced cellular concrete.

Science.gov (United States)

Lee, H K; Kim, H K; Hwang, E A

2010-02-01

Recently, millions tons of bottom ash wastes from thermoelectric power plants have been disposed of in landfills and coastal areas, regardless of its recycling possibility in construction fields. Fiber-reinforced cellular concrete (FRCC) of low density and of high strength may be attainable through the addition of bottom ash due to its relatively high strength. This paper focuses on evaluating the feasibility of utilizing bottom ash of thermoelectric power plant wastes as aggregates in FRCC. The flow characteristics of cement mortar with bottom ash aggregates and the effect of aggregate type and size on concrete density and compressive strength were investigated. In addition, the effects of adding steel and polypropylene fibers for improving the strength of concrete were also investigated. The results from this study suggest that bottom ash can be applied as a construction material which may not only improve the compressive strength of FRCC significantly but also reduce problems related to bottom ash waste.

Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

Energy Technology Data Exchange (ETDEWEB)

Van Wychen, Stefanie; Laurens, Lieve M. L.

2016-01-13

This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575 deg. C is covered for ash content.

Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

Science.gov (United States)

Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

2018-06-01

Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

INFLUENCE OF SILICEOUS AND CALCAREOUS FLY-ASHES ON PROPERTIES OF CEMENT MORTARS

Directory of Open Access Journals (Sweden)

Gabriela Monika Rutkowska

2016-09-01

Full Text Available Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. Construction and building industries have the greatest potential for reuse of waste. The article presents the results of investigations of cement mortars – tests of compressive and tensile strength after 28 and 56 days of curing – for normative mortars and mortars containing fly ashes – calcareous and siliceous ash – in their composition. To make the samples, the Portland cement CEM I 32,5 R, 42,5R and natural aggregate with graining of 0–2 mm were used. Concrete with siliceous and calcareous admixtures was made in six lots where the ash was added in the quantity of 2%, 5%, 10% of the cement mass or the 2%, 5%, 10% of cement was replaced by ashes. After the tests, it was stated that the siliceous fly-ash admixture increases the compressive and bending strength in comparison to the mortars with the calcareous ash admixtures.

Removal of metallic ions from aqueous solutions by fluidized bed fly ashes

Energy Technology Data Exchange (ETDEWEB)

Rio, S.; Delebarre, A.; Hequet, V. [Ecole des Mines de Nantes, 44 - Nantes (France); Blondin, J. [Cerchar 62 - Mazingarbe (France)

2001-07-01

One of the main constraints deriving from the generation of power by coal combustion is to find some use for the fly ashes instead of disposing of them. Fly ashes from two fluidized bed power plants were tested to remove Pb{sup 2+}, Cu{sup 2+}, Cr (III), Ni{sup 2+}, Zn{sup 2+} and Cr (VI) from aqueous solutions. Experimental design methodology was used to study the removal and the leaching as a function of (i) the water pollutant content, (ii) the metal concentration in water, (iii) the pH of the solution and (iv) the addition of lime to fly ashes. The results show that the percentage of adsorbed ions was more important when they were in contact with silico-aluminous fly ashes than sulfo-calcic fly ashes, except in the case of the ion Ni{sup 2+}. The removal of metallic ions increases with increasing pH. The metallic canons removal accounting for the leaching test was higher when lime was added to silico-aluminous fly ashes during the adsorption. (authors)

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.

Removal of uranium from simulated fly ash by chloride volatilization method

International Nuclear Information System (INIS)

Nobuaki, Sato; Yoshikatsu, Tochigi; Toshiki, Fukui; Takeo, Fujino

2003-01-01

Fly ash is generated from LWR nuclear power plant as a low-level waste, which is contaminated with a small amount of radioactive materials, composed mainly of uranium oxide. The constituents of the fly ash are similar to those of the ore; the major components of the ash are oxides of silicon, aluminum, sodium, magnesium, zinc, iron sodium and uranium. In this study, removal of uranium from the simulated fly ash, of which composition was U 3 O 8 : 10, CaO:25, SiO 2 : 25, Al 2 O 3 : 20, MgO: 10, ZnO:5, Fe 2 O 3 : 3 and Na 2 CO 3 : 2 wt%, by chloride volatilization method was examined. The simulated fly ash was chlorinated by the same manner as the dry way processing for the ore; namely, the ash was heated in a flow of chlorine in the presence of carbon at high temperatures. In the case of volatilization of uranium from U 3 O 8 and a simulated fly ash by chlorination using chlorine and carbon, it was seen that uranium of both samples showed similar volatilization behaviour: The volatilization ratio of uranium (VU) increased with increasing temperature from 800 to 1100 C. The VU value attained 99.9% at 1100 C. Iron, silicon and zinc showed similar behaviour to uranium, namely, they vaporized completely. The volatilization ratio of aluminum, magnesium and sodium were still high in a range 80-90%. The volatilization ratio of calcium was ∼40% under the same chlorination condition, though it changed to chloride. For recovery of uranium from fly ash by chlorination using chlorine in the presence of carbon, high volatilization ratio of uranium can be achieved at high temperatures. Volatilization ratio of other components also increases, which decreases the amount of decontaminated residue resulting in the reducing of decontamination effect. Selection of heating condition is important. (author)

Effect of fly ash characteristics on arsenic mobilization in the environment

International Nuclear Information System (INIS)

Bhumbla, D.K.; Singh, R.N.; Keefer, R.F.

1993-01-01

Coal combustion by products are a major source of arsenic mobilization in the environment. These by products have been successfully used in the reclamation of mine lands. However, there are concerns about the potential pollution problems from As by such use. A field experiment was established on a recently remined abandoned mine land where fly ashes from three different power plants were used for reclaiming mine soils. The experiment had seven treatments and 4 replications which were arranged in a randomized block design. The treatments consisted of 3 fly ashes at 2 rates each and a check treatment received lime. Arsenic content of the fly ashes varied between 53 and 220 mg/kg. Fly ashes also varied in the amounts of amorphous oxides of iron and neutralization potential. Arsenic concentrations were monitored in the vegetation, soil solutions, and soils. The results of this experiment showed that arsenic concentrations were higher in plants grown on plots receiving fly ash than in plants grown on plots receiving lime treatment. Arsenic concentrations in the plants, water, or soil were not governed by the arsenic content of fly ashes. Arsenic mobilization from the ashes was controlled by the chemical and morphological characteristics of the fly ashes and chemical transformations in the arsenic containing components in soil

Chemical associations and mobilization of heavy metals in fly ash from municipal solid waste incineration.

Science.gov (United States)

Weibel, Gisela; Eggenberger, Urs; Schlumberger, Stefan; Mäder, Urs K

2017-04-01

This study focusses on chemical and mineralogical characterization of fly ash and leached filter cake and on the determination of parameters influencing metal mobilization by leaching. Three different leaching processes of fly ash from municipal solid waste incineration (MSWI) plants in Switzerland comprise neutral, acidic and optimized acidic (+ oxidizing agent) fly ash leaching have been investigated. Fly ash is characterized by refractory particles (Al-foil, unburnt carbon, quartz, feldspar) and newly formed high-temperature phases (glass, gehlenite, wollastonite) surrounded by characteristic dust rims. Metals are carried along with the flue gas (Fe-oxides, brass) and are enriched in mineral aggregates (quartz, feldspar, wollastonite, glass) or vaporized and condensed as chlorides or sulphates. Parameters controlling the mobilization of neutral and acidic fly ash leaching are pH and redox conditions, liquid to solid ratio, extraction time and temperature. Almost no depletion for Zn, Pb, Cu and Cd is achieved by performing neutral leaching. Acidic fly ash leaching results in depletion factors of 40% for Zn, 53% for Cd, 8% for Pb and 6% for Cu. The extraction of Pb and Cu are mainly limited due to a cementation process and the formation of a PbCu 0 -alloy-phase and to a minor degree due to secondary precipitation (PbCl 2 ). The addition of hydrogen peroxide during acidic fly ash leaching (optimized acidic leaching) prevents this reduction through oxidation of metallic components and thus significantly higher depletion factors for Pb (57%), Cu (30%) and Cd (92%) are achieved. The elevated metal depletion using acidic leaching in combination with hydrogen peroxide justifies the extra effort not only by reduced metal loads to the environment but also by reduced deposition costs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stabilisation of clayey soils with high calcium fly ash and cement

Energy Technology Data Exchange (ETDEWEB)

S. Kolias; V. Kasselouri-Rigopoulou; A. Karahalios [National Technical University of Athens, Athens (Greece)

2005-02-01

The effectiveness of using high calcium fly ash and cement in stabilising fine-grained clayey soils (CL,CH) was investigated in the laboratory. Strength tests in uniaxial compression, in indirect (splitting) tension and flexure were carried out on samples to which various percentages of fly ash and cement had been added. Modulus of elasticity was determined at 90 days with different types of load application and 90-day soaked CBR values are also reported. Pavement structures incorporating subgrades improved by in situ stabilisation with fly ash and cement were analyzed for construction traffic and for operating traffic. These pavements are compared with conventional flexible pavements without improved subgrades and the results clearly show the technical benefits of stabilising clayey soils with fly ash and cement. In addition TG-SDTA and XRD tests were carried out on certain samples in order to study the hydraulic compounds, which were formed.

Ash fusion characteristics during co-gasification of biomass and petroleum coke.

Science.gov (United States)

Xiong, Qing-An; Li, Jiazhou; Guo, Shuai; Li, Guang; Zhao, Jiantao; Fang, Yitian

2018-06-01

In this study, the effect of biomass ash on petroleum coke ash fusibility was investigated at a reducing atmosphere. Some analytical methods, such as ash fusion temperatures (AFTs) analysis, X-ray diffraction (XRD), FactSage and scanning electron microscopy (SEM), were applied to determine the characteristics of ash fusion and transformation of mineral matters. The results indicated that AFTs were closely associated with ash mineral compositions. It was found that the formations of high melting point calcium silicate, vanadium trioxide and coulsonite resulted in the high AFTs of Yanqing petroleum coke (YQ). When blending with certain proportional pine sawdust (PS), corn stalk (CS), the AFTs of mixture could be decreased significantly. For PS addition, the formations of low-melting point calcium vanadium oxide should be responsible for the reduction of AFTs, whereas for CS addition the reason was ascribed to the formation of low-melting point leucite and the disappearance of high-melting V 2 O 3 . Copyright © 2018. Published by Elsevier Ltd.

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.

Comparative leaching of six toxic metals from raw and chemically stabilized MSWI fly ash using citric acid.

Science.gov (United States)

Wang, Huawei; Fan, Xinxiu; Wang, Ya-Nan; Li, Weihua; Sun, Yingjie; Zhan, Meili; Wu, Guizhi

2018-02-15

The leaching behavior of six typical toxic metals (Pb, Zn, Cr, Cd, Cu and Ni) from raw and chemically stabilized (phosphate and chelating agent) municipal solid waste incineration (MSWI) fly ash were investigated using citric acid. Leaching tests indicated that phosphate stabilization can effectively decrease the leaching of Zn, Cd and Cr; whereas chelating agent stabilization shows a strong ability to lower the release of Pb, Cd and Cu, but instead increases the solubility of Zn and Cr at low pH conditions. Sequential extraction results suggested that the leaching of Pb, Zn and Cd in both the stabilized MSWI fly ash samples led to the decrease in Fe/Mn oxide fraction and the increase in exchangeable and carbonate fractions. The leaching of Cr was due to the decrease in exchangeable, carbonate and Fe/Mn oxide fractions in phosphate-stabilized and chelating agent-stabilized MSWI fly ash. The leaching of Cu in both stabilized MSWI fly ash was greatly ascribed to the decrease in Fe/Mn oxide and oxidisable fractions. Moreover, predicted curves by geochemical model indicated that both stabilized MSWI fly ash have the risk of releasing toxic metals under strong acid environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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....

Fly Ash in Civil Engineering Stage 1: Inventory/Application; Flygaska i geotekniska anlaeggningar Etapp 1: Inventering/Tillaemplighet

Energy Technology Data Exchange (ETDEWEB)

Macsik, Josef; Svedberg, Bo; Lenstroemer, Stina; Nilsson, Thomas [Scandiaconsult, Stockholm (Sweden)

2004-01-01

The project presented below is the first phase of a broader project named FACE 'Fly Ash in Civil Engineering'. The objective of the project is to identify environmentally friendly products based on fly ash to be used in geotechnical applications such as road bases etc. In this phase of the project, named 'Inventory/Applicability', different fly ashes have been grouped according to their technical properties and potential applications. The objective of grouping fly ashes is to identify key-properties in order to make future investigations less extensive and also to make it easier to assess potential applications in the future. A total of nine different fly ashes from incineration of bio fuels (Heating Plants and Forest Industry Boilers) were investigated. The investigated fly ashes were all fresh and dry apart from two which originated from landfill. Properties such as grain-size distribution, water content, void-ratio, loss on ignition, compaction properties, increase of shear strength, have been investigated. Analyses of the results indicate that fly ashes can be divided into three main groups A, B and C, where: Group A fly ashes have poor curing properties and need stabilisation agents such as other fly ashes with higher curing capacity or cement (Portland cement, Merit 5000 etc.). Fly ash which has been stored in landfill and has a low content of quick lime is also part of this group. These fly ashes are not appropriate for use without addition of stabilising agent if they are to be used in applications where percolating water and frost-thaw cycles occur. After stabilisation with fresh fly ash and cement, fly ashes from this group can be used in sub-base in roads. Group B fly ashes have medium-high to high content of quick lime and good development of shear strength. These fly ashes can be used without being stabilised with cement. In fact, adding cement can reduce properties of compaction thus reducing the strength of a construction. The

Composition and microstructure of a furnace ash deposit from a coal-fired utility boiler

Energy Technology Data Exchange (ETDEWEB)

Fessler, R R

1980-07-01

An exploratory study of the structure and composition of furnace-ash deposits was carried out using optical metallography, electron microprobe analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. The results of these analyses were supplemented by studies of particulate melting temperature using hot-stage microscopy to measure melting temperature, and energy-dispersive X-ray analyses to measure composition of melted particles. It was found that the general structure of the ash deposit was a matrix of glassy, spherical particles having a wide range of composition in which unfused particles containing iron oxide and calcium oxide were dispersed. At the imprint of the tube surface a considerable concentration of calcium, sulphur and iron was found. Near the fused outer surface of the deposit, the glassy materials had melted into a porous, glassy slag containing spherical globules of iron oxide combined with other materials. There were no systematic compositional gradients from the tube surface to the fused outer layer except for the sulfur layer found only at the tube surface. However, there were significant differences in composition from particle to particle and these differences were similar to those found in the coal mineral matter as isolated by low-temperature ashing. Single particles of low-temperature ash were found having low fusion temperatures, in the range of fusion temperatures for particles in furnance has. Thus, the glassy spheres found in furnace deposits could originate from single coal particles, without the need of interactions among coal particles or ash particles.

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

Science.gov (United States)

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

2016-05-01

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

SHRINKAGE REDUCTION AND CRACK PREVENTION OF ALKALI-ACTIVATED PHOSPHOROUS SLAG CEMENT

Directory of Open Access Journals (Sweden)

Yanan Wang

2016-05-01

Full Text Available The effects of fly ash, calcium oxide and polypropylene fiber on the physical and mechanical properties, shrinkage and cracking behaviors of alkali-activated phosphorous slag cement (AA-PS-C were studied. The results show that replacing 10-15% phosphorous slag by fly ash and adding calcium oxide as an expansive agent reduce the shrinkage of AA-PS-C. Fly ash will increase the flexural strength, although the compressive strength will be slightly decreased, while the calcium oxide expansive agent coated with aluminum stearate will slightly shorten the setting time and reduce the strength. Adding polypropylene fiber can greatly increase the crack-resistance of AA-PS-C.

Progress and gaps in understanding mechanisms of ash tree resistance to emerald ash borer, a model for wood-boring insects that kill angiosperms.

Science.gov (United States)

Villari, Caterina; Herms, Daniel A; Whitehill, Justin G A; Cipollini, Don; Bonello, Pierluigi

2016-01-01

We review the literature on host resistance of ash to emerald ash borer (EAB, Agrilus planipennis), an invasive species that causes widespread mortality of ash. Manchurian ash (Fraxinus mandshurica), which coevolved with EAB, is more resistant than evolutionarily naïve North American and European congeners. Manchurian ash was less preferred for adult feeding and oviposition than susceptible hosts, more resistant to larval feeding, had higher constitutive concentrations of bark lignans, coumarins, proline, tyramine and defensive proteins, and was characterized by faster oxidation of phenolics. Consistent with EAB being a secondary colonizer of coevolved hosts, drought stress decreased the resistance of Manchurian ash, but had no effect on constitutive bark phenolics, suggesting that they do not contribute to increased susceptibility in response to drought stress. The induced resistance of North American species to EAB in response to the exogenous application of methyl jasmonate was associated with increased bark concentrations of verbascoside, lignin and/or trypsin inhibitors, which decreased larval survival and/or growth in bioassays. This finding suggests that these inherently susceptible species possess latent defenses that are not induced naturally by larval colonization, perhaps because they fail to recognize larval cues or respond quickly enough. Finally, we propose future research directions that would address some critical knowledge gaps. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Zeolite from fly ash: synthesis and characterization

Indian Academy of Sciences (India)

Unknown

to attempt making zeolite from fly ash (Höller and Wir- sching 1985; Henmi ... thermal treatment method to synthesize low silica NaX- type zeolite from .... catalytic applications. Mixture of ... amount of Fe2O3 and the oxides of Mg, Ca, P, Ti etc. The chemical ..... This work is partly supported by the Ministry of Human. Resource ...

Changes in oxidative potential of soil and fly ash after reaction with gaseous nitric acid

Science.gov (United States)

Zhan, Ying; Ginder-Vogel, Matthew; Shafer, Martin M.; Rudich, Yinon; Pardo, Michal; Katra, Itzhak; Katoshevski, David; Schauer, James J.

2018-01-01

The goal of this study was to examine the impact of simulated atmospheric aging on the oxidative potential of inorganic aerosols comprised primarily of crustal materials. Four soil samples and one coal fly ash sample were artificially aged in the laboratory through exposure to the vapor from 15.8 M nitric acid solution for 24 h at room temperature. Native and acid-aged samples were analyzed with a cellular macrophage and acellular dithionthreitol assays to determine oxidative potential. Additionally, the samples were analyzed to determine the concentration of 50 elements, both total and the water-soluble fraction of these elements by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICMS) and crystalline mineral composition using X-ray Diffraction (XRD). The results show that reactions with gaseous nitric acid increase the water-soluble fraction of many elements, including calcium, iron, magnesium, zinc, and lead. The mineral composition analysis documented that calcium-rich minerals present in the soils (e.g., calcite) are converted into different chemical forms, such as calcium nitrate (Ca(NO3)2). The nitric acid aging process, which can occur in the atmosphere, leads to a 200-600% increase in oxidative potential, as measured by cellular and acellular assays. This laboratory study demonstrates that the toxic effects of aged versus freshly emitted atmospheric dust may be quite different. In addition, the results suggest that mineralogical analysis of atmospheric dust may be useful in understanding its degree of aging.

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.

Supplying Fe from molten coal ash to revive kelp community

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, K.; Yamamoto, M.; Sadakata, M. [University of Tokyo, Tokyo (Japan)

2006-02-15

The phenomenon of a kelp-dominated community changing to a crust-dominated community, which is called 'barren-ground', is progressing in the world, and causing serious social problems in coastal areas. Among several suggested causes of 'barren-ground', we focused on the lack of Fe in seawater. Kelp needs more than 200 nM of Fe to keep its community. However there are the areas where the concentration of Fe is less than 1 nM, and the lack of Fe leads to the 'barren-ground.' Coal ash is one of the appropriate materials to compensate the lack of Fe for the kelp growth, because the coal ash is a waste from the coal combustion process and contains more than 5 wt% of Fe. The rate of Fe elution from coal fly ash to water can be increased by 20 times after melting in Ar atmosphere, because 39 wt% of the Fe(III) of coal fly ash was reduced to Fe(II). Additionally molten ash from the IGCC (integrated coal gasification combined cycle) furnace in a reducing atmosphere and one from a melting furnace pilot plant in an oxidizing atmosphere were examined. Each molten ash was classified into two groups; cooled rapidly with water and cooled slowly without water. The flux of Fe elution from rapidly cooled IGCC molten ash was the highest; 9.4 x 10{sup -6} g m{sup -2} d{sup -1}. It was noted that the coal ash melted in a reducing atmosphere could elute Fe effectively, and the dissolution of the molten ash itself controlled the rate of Fe elution in the case of rapidly cooled molten ash.

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.

The Effects of Eggshell Ash on Strength Properties of Cement-stabilized Lateritic

OpenAIRE

Okonkwo U. N; Odiong I. C; Akpabio E. E

2012-01-01

Eggshell ash obtained by incinerating Fowls’ eggshells to ash has been established to be a good accelerator for cement-bound materials and this would be useful for road construction work at the peak of rainy seasons for reducing setting time of stabilized road pavements. However this should be achieved not at the expense of other vital properties of the stabilized matrix. This is part of the effort in adding value to agricultural materials which probably cause disposal problems. Thus this stu...

Reducing retrogradation and lipid oxidation of normal and glutinous rice flours by adding mango peel powder.

Science.gov (United States)

Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

2016-06-15

Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sintering of MSW fly ash for reuse as a concrete aggregate.

Science.gov (United States)

Mangialardi, T

2001-10-12

The sintering process of municipal solid waste (MSW) fly ash was investigated in order to manufacture sintered products for reuse as concrete aggregates. Four types of fly ash resulting from different Italian MSW incineration plants were tested in this study. A modification of the chemical composition of MSW fly ash--through a preliminary four-stage washing treatment of this material with water--was attempted to improve the chemical and mechanical characteristics of sintered products.The sintering treatment of untreated or washed fly ash was performed on cylindrical compact specimens (15 mm in diameter and 20mm in height) at different compact pressures, sintering temperatures and times.The sintering process of untreated MSW fly ashes proved to be ineffective for manufacturing sintered products for reuse as a construction material, because of the adverse chemical characteristics of these fly ashes in terms of sulfate, chloride, and vitrifying oxide contents.A preliminary washing treatment of MSW fly ash with water greatly improved the chemical and mechanical characteristics of sintered products and, for all the types of fly ash tested, the sintered products satisfied the Italian requirements for normal weight aggregates for use in concretes having a specified strength not greater than 12 and 15N/mm(2), when measured on cylindrical and cubic specimens, respectively.A compact pressure of 28 N/mm(2), a sintering temperature of 1140 degrees C, and a sintering time of 60 min were the best operating conditions for manufacturing sintered products of washed MSW fly ash.

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,...

Mechanism research on coupling effect between dew point corrosion and ash deposition

International Nuclear Information System (INIS)

Wang, Yun-Gang; Zhao, Qin-Xin; Zhang, Zhi-Xiang; Zhang, Zhi-Chao; Tao, Wen-Quan

2013-01-01

In order to study the coupling mechanism between ash deposition and dew point corrosion, five kinds of tube materials frequently used as anti-dew point corrosion materials were selected as research objects. Dew point corrosion and ash deposition experiments were performed with a new type experimental device in a Chinese thermal power plant. The microstructures of the materials and the composition of ash deposition were analyzed by X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS). The results showed that the ash deposition layer could be divided into non-condensation zone, the main condensation zone and the secondary condensation zone. The acid vapor condensed in the main condensation zone rather than directly on the tube wall surface. The dew point corrosion mainly is oxygen corrosion under the condition of the viscosity ash deposition, and the corrosion products are composed of the ash and acid reaction products in the outer layer, iron sulfate in the middle layer, and iron oxide in the inner layer. The innermost layer is the main corrosion layer. With the increase of the tube wall temperature, the ash deposition changes from the viscosity ash deposition to the dry loose ash deposition, the ash deposition rate decreases dramatically and dew point corrosion is alleviated efficiently. The sulfuric dew point corrosion resistance of the five test materials is as follows: 316L > ND > Corten>20G > 20 steel. -- Highlights: ► Dew point corrosion and ash deposition tests of five materials were performed. ► Acid vapor condensed in the ash deposit rather than directly on the tube surface. ► Dew point corrosion resistance is as follow: 316L > ND > Corten>20G > 20 steel. ► Dew point corrosion mainly is oxygen corrosion under viscosity ash deposition

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 ...

Effect of CaCO_3 addition on ash sintering behaviour during K_2CO_3 catalysed steam gasification of a Chinese lignite

International Nuclear Information System (INIS)

Zhang, Jiguang; Li, Jianbo; Mao, Yandong; Bi, Jicheng; Zhu, Mingming; Zhang, Zhezi; Zhang, Li; Zhang, Dongke

2017-01-01

Highlights: • K_2CO_3 decreased ash sintering temperature and enhanced ash melting in gasification. • CaCO_3 addition enhanced ash melting and lowered ash sintering temperatures. • CaCO_3 reacted with SiO_2 to form fluxing phases and amorphous materials. • CaCO_3 addition inhibited the potassium aluminium silicate formation. • CaCO_3 addition preserved the catalytic activity of potassium. - Abstract: The ash sintering behaviour of a Chinese lignite (LLI) with different amounts of CaCO_3 addition during K_2CO_3-catalysed gasification was investigated. 0–10 wt% K_2CO_3 was doped into the lignite for catalytic gasification, and CaCO_3 was added into the K_2CO_3-doped samples, varying in the range of 0–20 wt% relative to the lignite, for understanding its impact on ash sintering and catalytic gasification activity. Ash samples were prepared by completely gasifying the lignite samples with steam in a fixed-bed catalytic gasification system operating at 1073 K and atmospheric pressure. Sintering temperature, mineralogy and morphology of the ash samples thus obtained were determined using a pressure-drop sintering device, XRD and SEM-EDS, respectively. The results showed that the ash sintering temperature decreased as the K_2CO_3 addition increased, indicating that K_2CO_3 as the catalyst for gasification would promote ash sintering. SEM imaging analysis showed that all the ash samples from LLI with K_2CO_3 addition were composed of agglomerated particles with smooth surfaces, indicating the ashes had incurred partial melting. The degree of melting became more apparent as the K_2CO_3 addition ratio increased. These molten phases were identified as K-bearing arcanite and kaliophilite, which contributed to the formation of liquid phases at lower temperatures, resulting in lowered ash sintering temperatures. It was also revealed that the addition of CaCO_3 decreased the sintering temperatures of ash samples, indicating that the ash sintering was further

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.

Modeling and Prediction of Coal Ash Fusion Temperature based on BP Neural Network

Directory of Open Access Journals (Sweden)

Miao Suzhen

2016-01-01

Full Text Available Coal ash is the residual generated from combustion of coal. The ash fusion temperature (AFT of coal gives detail information on the suitability of a coal source for gasification procedures, and specifically to which extent ash agglomeration or clinkering is likely to occur within the gasifier. To investigate the contribution of oxides in coal ash to AFT, data of coal ash chemical compositions and Softening Temperature (ST in different regions of China were collected in this work and a BP neural network model was established by XD-APC PLATFORM. In the BP model, the inputs were the ash compositions and the output was the ST. In addition, the ash fusion temperature prediction model was obtained by industrial data and the model was generalized by different industrial data. Compared to empirical formulas, the BP neural network obtained better results. By different tests, the best result and the best configurations for the model were obtained: hidden layer nodes of the BP network was setted as three, the component contents (SiO2, Al2O3, Fe2O3, CaO, MgO were used as inputs and ST was used as output of the model.

Effects of wood chip ash fertilization on soil chemistry in a Norway spruce plantation on a nutrient-poor soil

DEFF Research Database (Denmark)

Ingerslev, Morten; Hansen, Mette; Pedersen, Lars Bo

2014-01-01

of wood chip ash application on soil chemistry in a 44-year-old Norway spruce (Picea abies) plantation on a nutrient-poor soil in Denmark and to investigate the effect of applying different ash types and doses. Soil samples were collected and analyzed 2.5years (3 growing seasons) after ash application....... This study shows that, regardless of ash formulation, preparation or dose, application of wood ash to forest soil has a liming effect in the O-horizon manifested as an increase in CECe, BS and pH. This effect was not seen in the mineral soil within the time frame of this study. At the same time, an increase...... in Cd was found in the O-horizon, corresponding to the amount added in the ashes. Generally, no other increase in soil contents of the heavy metals was seen. Hardening of the wood ash did not decrease the chemical impact on the soil chemistry as compared to non-treated ash whereas an increase in ash...

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

The Effect of Using Sewage Sludge Ash with and without Nano Silica Particles on Properties of Self-compacting Cement Based Materials

Directory of Open Access Journals (Sweden)

Amin Khoshravesh

2014-10-01

Full Text Available Nowadays using pozzolanic materials is crucial as a replacement of needed cement, improving properties of cement based materials and saving costs. On the other hand sewage sludge is harmful to the environment and human health. So in this research the sewage sludge ash has been used as an artificial pozzolan to produce self compacting cement based materials which could be evaluated as a revolution in the concrete industry. The objective of this research was to accelerate the performance of sewage sludge ash by utilizing nano silica particles. This research includes 10 mix designs for self compacting mortar and concrete made up of binary and ternary cementitious blends of sewage sludge ash (0%,5%,10%,15%,20% and nano silica (0%,1%. The results showed that by adding the sewage sludge ash, rheological and mechanical properties of the samples were reduced and for small percentages of sewage sludge ash, the durability characteristics were improved. The results also showed that adding nano silica improved the mechanical and durability properties of self compacting mortar and concrete. Finally in presence of nano silica, the reactivity of the sewage sludge ash was increased and its performance was improved.

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

International Nuclear Information System (INIS)

Eriksson, Jan

1996-01-01

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

Surface-coated fly ash used as filler in biodegradable poly(vinyl alcohol) composite films: Part 1-The modification process

International Nuclear Information System (INIS)

Nath, D.C.D.; Bandyopadhyay, S.; Gupta, S.; Yu, A.; Blackburn, D.; White, C.

2010-01-01

The surfaces of fly ash (FA) particles were modified by surfactant, sodium lauryl sulphate (SLS) and used in fabrication of composite films with polyvinyl alcohol (PVA). Both unmodified fly ash (FA) and modified fly ash (SLS-FA) samples were examined using a range of analytical tools including X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The distribution patterns of SLS-FA particles were shifted to the higher regions compared to FA by adding 1.2-4.2 μm in the ranges between 2 and 25 μm, whereas the modification process reduced the size of the particles over 25 μm due to grinding during the activation process. The increased 1.2-4.2 μm in average can be considered the thickness of the surfactant on the SLS-FA surface. On the oxides based chemical analysis by XRF, the compositions were almost unchanged. SEM and TEM were visualised the irregular sizes morphology mostly spherical of the particles, although it is impossible to capture the images of exactly same particles in modified and unmodified forms. The composite films reinforced with SLS-FA showed 33% higher strength than those of FA filled films. The enhancement of tensile strength attributed from the level of physical bonding between SLS-FA and PVA surfaces.

Clay stabilization by using gypsum and paddy husk ash with reference to UCT and CBR value

Science.gov (United States)

Roesyanto; Iskandar, R.; Hastuty, I. P.; Dianty, W. O.

2018-02-01

Clays that have low shear strength need to be stabilized in order to meet the technical requirements to serve as a subgrade material. One of the usual soil stabilization methods is by adding chemicals such as Portland cement, lime, and bitumen. The clay stabilization research was done by adding gypsum and paddy husk ash. The research goals were to find out the value of engineering properties of clay due to the addition of 2% gypsum and 2% - 15% paddy husk ash. The soil was classified as Clay - Low Plasticity (CL) based on USCS and was classified as A-7-6 (10) based on AASHTO classification system. The UCT value of original soil was 1.41 kg/cm2. While the CBR soaked and unsoaked values of original soil were 4.41% and 6.23% respectively. The research results showed the addition of paddy husk ash decreased the value of unconfined compressive strength as well as CBR. The stabilized soil by 2% gypsum and 0% paddy husk ash gave maximum UCT value of 1.67 kg/cm2, while the maximum value of CBR were found 6.71% for CBR soaked and 8.00% for CBR unsoaked. The addition of paddy husk ash did not alter the soil classification according to AASHTO or USCS, even degrade the engineering properties of original soil.

Bamboo leaf ash as the stabilizer for soft soil treatment

Science.gov (United States)

Rahman, A. S. A.; Jais, I. B. M.; Sidek, N.; Ahmad, J.; Rosli, M. I. F.

2018-04-01

Soft soil is a type of soil that have the size of particle less than 0.063mm. The strength of the soft soil does not fulfil the requirement for construction. The present of soft soil at the construction site always give a lot of problems and issues to geotechnical sector. Soil settlement is one of the problems that related to soft soil. The determination of the soft soil physical characteristics will provide a detail description on its characteristic. Soft soil need to be treated in order to gain the standard strength for construction. One of the method to strengthen the soft soil is by using pozzolanic material as a treatment method for soft soil. Furthermore bamboo leaf ash is one of the newly founded materials that contain pozzolanic material. Any material that consist of Silicon Dioxide (SiO2) as the main component and followed by Aluminium Oxide (Al2O3) and Iron Oxide (Fe2O3) are consider as pozzolanic material. Bamboo leaf ash is mix with the cement as the treatment material. Bamboo leaf ash will react with the cement to produce additional cement binder. Thus, it will increase the soil strength and will ease the geotechnical sector to achieve high quality of construction product.

Fly ash as a sorbent for the removal of biologically resistant organic matter

Energy Technology Data Exchange (ETDEWEB)

Vandenbusch, M B; Sell, N J [Wisconsin Public Service Corporation, Green Bay, WI (USA)

1992-02-01

Six different fly ashes, in both an untreated and an acidified form, were studied with respect to their ability to remove colour and organic materials from a municipal waste treatment facility effluent. Colour, fluorescence, and chemical oxygen demand were used to monitor the removal. The apparent predominant mechanism varies with the pH and the chemical characteristics of the ash. These mechanisms include carbon sorption, calcium precipitation of tannins and humics, sorption on the fly ash surface by silica, alumina, and/or iron oxide and, in the acidified situation, coagulation of coloured colloids in the effluent dissolved from the fly ash. Some additional deleterious components are dissolved into the effluent during the treatment process. Many of these materials can, however, be removed by using a two-stage fly ash sorption process. Particularly of interest is the ability to remove over 90% of the boron from the effluent. 13 refs., 10 figs., 9 tabs.

Leaching behavior of harmful components from cement solidities of fluidized-bed coal ash

Energy Technology Data Exchange (ETDEWEB)

Baba, T.; Fukuoka, H.; Shigemoto, N. [Fuji Clean Co., Kagawa (Japan)

2008-07-15

Solidifies of fluidized-bed fly ash with slag cement were prepared by hydrothermal treatment after adding gypsum, Na3PO{sub 4}, or Al2(SO{sub 4}){sub 3}. XRD analysis of the solidifies was performed and leaching behavior of Pb and F from the solidities was investigated. The fly ash-cement and fly ash-cement-gypsum solidifies showed rather high leaching concentration of F and Pb. The F leaching was explained by solubility products of a Ca(OH){sub 2} CaF2 system. The Pb leaching concentrations roughly agreed with the theoretical curve for hydroxo complexes of Pb, showing a strong dependence on pH. Addition of Na3PO{sub 4} and Al2(SO{sub 4}){sub 3}, to cement solidities gave katoite and aluminium phosphate, and ettringite, respectively, and these solidities showed lower leaching concentrations of F and Pb than the fly ash-cement and fly ash-cement-gypsum solidifies. Capture of F and Pb in crystalline components such as ettringite probably accounts for such leaching suppression.

Radiological assessment of the utilization of fly ash in concrete for building construction and the parameters affecting radon-222 emanation from fly ash concrete

International Nuclear Information System (INIS)

Hwang, J.G.

1986-01-01

In this study, the Rn-222 area exhalation rates and the maximum area exhalations for concrete containing fly ash or Ra-226 water were measured. Various concrete samples were fabricated with fly ash of known radium content as a cement substitute. Other samples were prepared with one of three concentrations of Ra-226 water solution added into the concrete mix. A newly designed Indoor/Outdoor Emanation Chamber. The Ra-225 concentrations for the fly ash used ranged from 3.42 pCi/g to 7.55 pCi/g depending upon the source of the ash and the particle size. Doses were calculated for occupants of a hypothetical house built with concrete of the type studied. Doses to the basal cells of the bronchial epithelium and the mean dose to the lung were 2.10 rad/yr and 0.37 rad/yr for standard concrete, up to 4.28 rad/yr and 0.76 rad/yr for fly ash concrete, and 3.26 rad/yr and 0.58 rad/yr for the concrete made with 25 pCI/L radium-226 water. The risk associated with utilization of standard concrete in an unventilated house was estimated to range from 560 to 1316 fatal cancers in million population. Utilization of fly ash as a cement substitute could increase the number of fatal lung cancers up to 2680. Introducing 25 pCi/L Ra-226 water into concrete will increase the fatal cancer rate up to 2042 in a million population

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

partitioning effect, but crucially, disparities between surface and bulk chemistry remain evident. Simple glass-plagioclase mixing calculations suggest that this feature may indicate differences in bulk and surface mineral distributions; future QEMSCAN analysis will investigate this possibility further. Additionally, surface iron enrichments observed in our high temperature experiments suggest that hot oxidation effects can have a near-instantaneous, measurable effect on ash surface chemistry at the nanometre scale. Our preliminary results suggest that the chemical and mineral properties of the source magma, coupled with high temperature fragmentation processes, may have a significant influence on ash surface chemistry and mineralogy, and subsequently, on the post-eruptive alteration of ash particles and their reactivity within biotic and abiotic systems.

Biomass ash reutilisation as an additive in the composting process of organic fraction of municipal solid waste.

Science.gov (United States)

Asquer, Carla; Cappai, Giovanna; De Gioannis, Giorgia; Muntoni, Aldo; Piredda, Martina; Spiga, Daniela

2017-11-01

In this work the effects of selected types of biomass ash on the composting process and final product quality were studied by conducting a 96-day long experiment where the source separated organic fraction of municipal waste, mixed with wood prunings that served as bulking agent, was added with 0%, 2%, 4% and 8% wt/wt of biomass ash. The evolution over time of the main process parameters was observed, and the final composts were characterised. On the basis of the results, both the composting process and the quality of the final product were improved by ash addition. Enhanced volatile solids reduction and biological stability (up to 32% and 52%, respectively, as compared to the unamended product) were attained when ash was added, since ash favored the aerobic degradation by acting asa physical conditioner. In the final products, higher humification of organic matter (expressed in terms of the humification index, that was 2.25 times higher in the most-enriched compost than in the unamended one) and total Ca, K, Mg and P content were observed when ash was used. The latter aspect may influence the composts marketability positively, particularly with regards to potassium and phosphorus. The heavy metals content, that is regarded as the main environmental disadvantage when using ash asa composting additive, did not negatively affect the final composts quality. However, some other controversial effects of ash, related to the moisture and temperature values attained during the process, pH (8.8-9.2 as compared to 8.2 of the unamended compost) and electrical conductivity levels (up to 53% higher as compared to the unamended compost) in the final composts, were also observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Utilization of power plant bottom-ash particles as stabilizer in aluminum foams

Energy Technology Data Exchange (ETDEWEB)

Asavavisithchai, Seksak; Prapajaraswong, Attanadol [Chulalongkorn Univ., Bangkok (Thailand). Dept. of Metallurgical Engineering

2013-07-01

Aluminum foams, produced via powder metallurgical (PM) process, normally require the addition of ceramic particles in compaction stage, in order to increase both foamability of precursors and mechanical properties of the final foam products. Bottom ash particles are a by-product waste obtained from thermoelectric power plants which are commonly found to be used in landfill facilities. The major chemical constituent, approximately between 30 wt.-% and 60 wt.-%, of bottom ash particles is SiO{sub 2}, depending on chemical composition in coal, sintering condition and environment, and other process parameters. In this study, we explore the feasibility of utilizing bottom ash particles of thermoelectric power plant wastes as stabilizer in aluminum foams. A small amount of two-size bottom ash particles (mean size of 78 {mu}m and 186 {mu}m), between 1 wt.-% and 5 wt.-%, have been added to aluminum foams. Foam expansion, macro- and microstructures as well as mechanical properties, such as compressive strength and microhardness, were investigated. The results from the present study suggest that bottom ash particles can be used as a stabilizing material which can improve both cellular structure and mechanical properties of aluminum foams. (orig.)

Effect of additives in reducing ash sintering and slagging in biomass combustion applications

Energy Technology Data Exchange (ETDEWEB)

Wang, Liang

2012-07-01

The objective of this study was to investigate sintering and slagging behaviors of biofuels during combustion processes. Biofuels tested are derived from the agricultural sector, wood and furniture industry as well as from municipal sewage sludge. It was also the aim to test and evaluate additives that can prevent and abate biomass ash sintering by conducting laboratory and industrial scale tests. Sintering characteristics of sewage sludge ashes at elevated temperatures were investigated by means of different laboratory methods. Utilizing of phosphorus participation agents Al2(SO4)3 or Fe2(SO4)3 caused substantially high contents of aluminum or iron in the studied sewage sludge ashes, respectively. High initial melting temperatures over 1100 degrees C and low sintering tendencies were observed from the sewage sludge ashes rich in aluminum. It was related to presence and formation of the inert mineral phases such as aluminum oxide, quartz and calcium aluminum silicates in the aluminum rich sewage sludge ashes at elevated temperatures. A low melting temperature, about 994 degree C, was detected from the iron rich sewage sludge ash. Severe sintering of this sewage sludge ash was mainly due to generation of low temperature melting iron silicates, as results of interaction and re-assemblage of hematite (Fe2O3), quartz (SiO2) and alkali feldspars under heating. Fusion behaviors of corn cob ashes under rising temperatures were characterized. The work revealed that chemical compositions of corn cob ashes are dominated by potassium, silicon, chlorine and phosphorus. However, the relative concentrations of these principal elements are considerably different for three studied corn cob ashes, which have major influence on ash transformation reactions and sintering tendencies. Compared with the other two, the chemical composition of the Waimanalo corn cob (WCob) was characterized with the highest K/Cl, Si/(Ca+Mg) and (Si+P+K)/(Ca+Mg) molar ratios, which was favorable for

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...

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.)

The use of fractionated fly ash of thermal power plants as binder for production of briquettes of coke breeze and dust

Science.gov (United States)

Temnikova, E. Yu; Bogomolov, A. R.; Lapin, A. A.

2017-11-01

In this paper, we propose to use the slag and ash material of thermal power plants (TPP) operating on pulverized coal fuel. The elemental and chemical composition of fly ash of five Kuzbass thermal power plants differs insignificantly from the composition of the mineral part of coking coal because coke production uses a charge, whose composition defines the main task: obtaining coke with the required parameters for production of iron and steel. These indicators are as follows: CRI reactivity and strength of the coke residue after reaction with CO2 - CSR. The chemical composition of fly ash of thermal power plants and microsilica with bulk density of 0.3-0.6 t/m3 generated at production of ferroalloys was compared. Fly ash and microsilica are the valuable raw material for production of mineral binder in manufacturing coke breeze briquettes (fraction of 2-10 mm) and dust (0-200 μm), generated in large quantities during coking (up to 40wt%). It is shown that this binder is necessary for production of smokeless briquettes with low reactivity, high strength and cost, demanded for production of cupola iron and melting the silicate materials, basaltic rocks in low-shaft furnaces. It is determined that microsilica contains up to 90% of silicon oxide, and fly ash contains up to 60% of silicon oxide and aluminum oxide of up to 20%. On average, the rest of fly ash composition consists of basic oxides. According to calculation by the VUKHIN formula, the basicity index of briquette changes significantly, when fly ash is introduced into briquette raw material component as a binder. The technology of coke briquette production on the basis of the non-magnetic fraction of TPP fly ash in the ratio from 3.5:1 to 4.5:1 (coke breeze : coke dust) with the addition of the binder component to 10% is proposed. The produced briquettes meet the requirements by CRI and require further study on CSR requirements.

Development of an ash particle deposition model considering build-up and removal mechanisms

Energy Technology Data Exchange (ETDEWEB)

Strandstroem, Kjell; Mueller, Christian; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Biskopsgatan 8, FI-20500 Aabo (Finland)

2007-12-15

Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling is since long considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. (author)

Development of an ash particle deposition model considering build-up and removal mechanisms

Energy Technology Data Exchange (ETDEWEB)

Kjell Strandstroem; Christian Muellera; Mikko Hupa [Abo Akademi Process Chemistry Centre, Abo (Finland)

2007-12-15

Slagging and fouling on heat exchanger surfaces in power boilers fired with fossil fuels and fuel mixtures has a significant influence on boiler efficiency and availability. Mathematical modelling has long been considered a suitable method to assist boiler operators to determine optimized operating conditions for an existing furnace. The ultimate goal in ash deposition prediction is hereby the determination of the total amount of material deposited and hence the determination of the total reduction in efficiency. Depending on the fuels fired the total deposited mass is a combination of ash particle deposition and ash particle erosion due to non-sticky particles. The novel ash particle deposition model presented in this work considers deposition of sticky ash particles, cleansing of deposit by non-sticky sand particles and sticking of sand due to contact with sticky ash. The steady-state modelling results for the total amount of ash deposited on the deposition probe of an entrained flow reactor presented in this work agree well with the experimental data. Only at very high fractions of sand added as non-sticky material, a significant influence of the sand on the overall mass deposited was found. Since the model considers sticking of non-sticking sand due to contact with sticky ash, the fraction of sand deposited on the probe was especially studied. Using a correction factor to consider the influence of operating time on the steady-state simulations led to good agreement between simulations and experimental data. 12 refs., 10 figs.

In-situ treatment of acid mine waters using fluidized bed ash: Field study

International Nuclear Information System (INIS)

Everett, J.W.; Canty, G.A.

1999-01-01

A slurry of mine water and fluidized bed ash (FBA) was injected into an abandoned coal mine in eastern Oklahoma in July 1997. Oil-field technology was used to inject 1.8 Gg (418 tons) of FBA through five wells in 15 hours. Prior to injection the seep water had a pH of 4.4, was net acidic (acidity over 400 mg/L as CaCO 3 ), and had relatively high metal concentrations (in mg/L: Fe-200; Mn-7; and Al-6). After injection, during the period of effective treatment, the seep water had a pH above 6.0, less net acidity, and had lower metals concentrations (in mg/L: Fe-120; Mn-5; and Al-< PQL). When the treated seep water exited the mine, the dissolved metals oxidized and hydrolyzed. As the metals precipitated, the alkalinity introduced by the FBA was consumed and the pH dropped. However, the seep water characteristics upon entering the receiving stream were improved, compared to pre-injection. The resulting seep water quality is such that it is more amenable to further treatment by passive treatment methods, such as anoxic limestone drains or wetlands. Alkaline injection is a finite treatment process. Eventually, the added alkalinity is exhausted, at which time the seep returns to pre-injection conditions, necessitating another injection of ash. For the study discussed in this paper, the treatment lasted approximately 15 months. While the amount of alkalinity added to the mine could have potentially treated much more than a year's volume of seep water, it is believed that much of the injected alkalinity was unavailable in backwater areas in the mine. This alkalinity contributed little, if any, to the treatment of water flowing through the mine. Mine hydrology, especially during injection are crucial to treatment longevity

Effects of soil application of fly ash on the fusarial wilt on tomato cultivars

Energy Technology Data Exchange (ETDEWEB)

Khan, M.R.; Singh, W.N. [Aligarh Muslim University, Aligarh (India). Dept. of Plant Protection, Rafi Ahmad Kidwai Institute of Agricultural Science

2001-07-01

A study was carried out in microplots to evaluate the effect of fly ash on the plant growth and yield of tomato cultivars, Pusa Ruby, Pusa Early Dwarf and New Uday, and on wilt disease caused by Fusarium oxysporum f. sp. lycopersici. Fly ash was applied to soil by broadcast or in rows at the rate of 1, 2, 3 and 4 kg ash m{sup -2} in place of inorganic fertilizers. In control plots, NPK (about 40 : 20 : 20 kg acre{sup -1}) and compost were added in place of fly ash. Ash application greatly increased the soil contents of P, K, B, Ca, Mg, Mn, Zn, carbonates, bicarbonates and sulphates. Plants grown in the ash-treated plots, especially at 3 or 4 kg dose, showed luxuriant growth and greener foliage, and plant growth and yield of the three cultivars were significantly increased in comparison with the plants grown in plots without fly ash. The wilt fungus, F. oxysporum f. sp. lycopersiciat the inoculum level of 2 g plant{sup -1} caused significant suppression of growth and yield in all three cultivars. Application of fly ash, however, checked the suppressive effect of the fungus, leading to a significant increase in the considered variables compared with the inoculated control. Soil population of the fungus gradually decreased with an increase in ash dose. Row application was found to be relatively more effective in enhancing the yield of tomato cultivars and suppressing the wilt disease.

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

Science.gov (United States)

Eliche-Quesada, D; Leite-Costa, J

2016-02-01

Olive pomace bottom ash was used to replace different amounts (10-50wt%) of clay in brick manufacturing. The aim of this study is both studying bricks properties and showing a new way of olive pomace bottom ash recycling. Properties of waste bricks were compared to conventional products following standard procedures in order to determine the maximum waste percentage. The amount of olive pomace bottom ash is limited to 20wt%, obtaining bricks with superior engineering properties when 10wt% of waste is added. Adding higher amount of waste (30-50wt%) resulted in bricks with water absorption and compressive strength values on the edge of meeting those established by standards. Therefore, the addition of 10 and 20wt% of olive pomace bottom ash produced bricks with a bulk density of 1635 and 1527kg/m(3) and a compressive strength of 33.9MPa and 14.2MPa, respectively. Fired bricks fulfil standards requirements for clay masonry units, offering, at the same time, better thermal insulation of buildings due to a reduction in thermal conductivity of 14.4% and 16.8% respectively, compared to control bricks (only clay). Copyright © 2015 Elsevier Ltd. All rights reserved.

Inorganic contaminants attenuation in acid mine drainage by fly ash and fly ash-ordinary Portland cement (OPC) blends : column experiments

International Nuclear Information System (INIS)

Gitari, W.M.; Petrik, L.F.; Etchebers, O.; Key, D.L.; Okujeni, C.

2010-01-01

The infiltration of acid mine drainage (AMD) material into mine voids is one of the environmental impacts of underground coal mining. In this study, the mitigation of AMD in a mine void was simulated in laboratory conditions. Various mixtures of fly ash, solid residues, and Portland cement were added to packed columns over a 6-month period. The fly ash additions generated near-neutral to alkaline pH levels, which in turn induced precipitation, co-precipitation, and adsorption contaminant attenuation mechanisms. A modelling study demonstrated that the precipitation of ferrihydrite, Al-hydroxides, Al-oxyhydroxysulphates, gypsum, ettringite, manganite, and rhodochrosite lowered contaminant levels. Results of the study indicated that the pH regime and acidity level of the AMD strongly influenced both the leaching of the toxic trace elements as well as the attenuation of the AMD. 3 refs., 2 figs.

Enhancing the compressive strength of landfill soil using cement and bagasse ash

Science.gov (United States)

Azim, M. A. M.; Azhar, A. T. S.; Tarmizi, A. K. A.; Shahidan, S.; Nabila, A. T. A.

2017-11-01

The stabilisation of contaminated soil with cement and agricultural waste is a widely applied method which contributes to the sustainability of the environment. Soil may be stabilised to increase strength and durability or to prevent erosion and other geotechnical failure. This study was carried out to evaluate the compressive strength of ex-landfill soil when cement and bagasse ash (BA) are added to it. Different proportions of cement (5%, 10%, 15% and 20%) was added to sample weights without BA. On the other hand, the cement in a different batch of sample weights was replaced by 2.5%, 5%, 7.5% and 10% of BA. All samples were allowed to harden and were cured at room temperature for 7, 14 and 28 days respectively. The strength of the contaminated soil was assessed using an unconfined compressive strength test (UCS). The laboratory tests also included the index properties of soil, cement and bagasse ash in raw form. The results indicated that the samples with cement achieved the highest compressive strength measuring 4.39 MPa. However, this study revealed that the use of bagasse ash produced low quality products with a reduction in strength. For example, when 5% of cement was replaced with 5% ash, the compressive strength decreased by about 54% from 0.72 MPa to 0.33 MPa. Similarly, the compressive strength of each sample after a curing period of 28 days was higher compared to samples cured for 7 and 14 days respectively. This is proved that a longer curing period is needed to increase the compressive strength of the samples.

Fly ash as a binder in aggregate base courses

International Nuclear Information System (INIS)

Zenieris, P.; Laguros, J.G.

1988-01-01

The benefit of adding up to 35 wt% Class C high calcium fly ash to various types of fine and coarse aggregate pavement mixes is described and quantified. The mixes, which were compacted to maximum dry density at optimum moisture content, had variable compressive strengths during the first 28 day of curing; after that they assumed a relatively uniform pattern of strength gain reaching values as high as 11 MPa (1600 psi). Mixes containing 15% fly ash gave unacceptably low strengths. XRD measurements indicated massive formation of ettringite, transforming to monosulfoaluminate and the poorly crystallized hydrated phases of C-A-H, C-A-S-H and C-S-H. This transformation helps explain the gain in strength of the mixes with extended curing. SEM observations depicted progressive packing and densification of the skeletal matrix as the hexagonal phases and C-S-H gained higher crystallinity and formed aggregate masses. Furthermore, these observations suggest that fly ash acts predominantly as a chemical binder and partly as a filler in the aggregate mixes tested

Effect of unground oil palm ash as mixing ingredient towards properties of concrete

Science.gov (United States)

Sulaiman, M. A.; Muthusamy, K.; Mat Aris, S.; Rasid, M. H. Mohd; Paramasivam, R.; Othman, R.

2018-04-01

Malaysia being one of the world largest palm oil producers generates palm oil fuel ash (POFA), a by-product in increasing quantity. This material which usually disposed as solid waste causes pollution to the environment. Success in converting this waste material into benefitting product would reduce amount of waste disposed and contributes towards cleaner environment. This research explores the potential of unground oil palm ash being used as partial sand replacement in normal concrete production. Experimental work has been conducted to determine the workability, compressive strength and flexural strength of concrete when unground oil palm ash is added as partial sand replacement. A total of five mixes containing various percentage of oil palm ash, which are 0%, 5%, 10%, 15% and 20% have been prepared. All specimens were water cured until the testing date. The slump test, compressive strength test and flexural strength test was conducted. The findings show that mix produced using 10% of palm oil fuel ash exhibit higher compressive strength and flexural strength as compared to control specimen. Utilization of unground oil palm ash as partial sand replacement would be able to reduce dependency of construction industry on natural sand supply and also as one of the solution to reuse palm oil industry waste.

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)

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

Science.gov (United States)

Brook, Anna; Hamzi, Seham; Wittenberg, Lea

2015-04-01

gradient of layered ash with diverse physicochemical properties. The obtained post-burned soils were processed as following: 1. loss of mass (ML); 2. ash layers sampling - the produced ash layers were collected separately; 3. grinding; 4. color - the Munsell colour chart; 5. spectroscopy- each sample was analysed by two spectrometer, first is the Ocean Optics USB4000 (0.35-1.05 μm) portable system across visible and near infrared (VNIR) region using contact Halogen illumination, second is the Bruker Tensor II (2.35-25 μm) across mid infrared (MIR) region by Furrier transform IR (FTIR) system using the Pike EasiDiff diffuse reflectance spectroscopy (DRS) optical bench; 6. pH and electrical conductivity (EC) including total dissolve solids (TDS) and salinity (S) measurements. The result of high concentration of carbonates, oxides, and hydroxides of basic cations decreasing EC levels caused by high pH (>8) there the CaCO3 surfaces are negatively charged and variation of mineralogical composition introducing very detailed list of minerals (high concentration of Nickeline NiAs, Cuprite Cu2O, Rehodochrosite MnCO3 and Nitrolite Na2Al2Si3O102H2O in the top-layers and mixtures e.g. Kaolinite/Smectite (85% Kaol.) Al2Si2O5(OH)4+(Na,Ca)0.33(Al,Mg)2Si4O10(OH)2nH2O and Mesolite + Hydroxyapophyllite Na2Ca2Al6Si9O308H2O + KCa4Si8O20(OH,F)8H2O between ash and post-burn top-soil layers. Bodí M.B., Muñoz-Santa I., Armero C., Doerr S.H., Mataix-Solera J., Cerdà A., 2013. Spatial and temporal variations of water repellency and probability of its occurrence in calcareous Mediterranean rangeland soils affected by fires. Catena, vol. 108, pp. 14-24. Certini G., Scalenghe R., Woods W.W., 2013. The impact of warfare on the soil environment. Earth-Science Reviews, vol. 127, pp. 1-15. Keesstra S.D., Temme A.J.A.M., Schoorl J.M., Visser S.M., 2014. Evaluating the hydrological component of new catchment-scale sediment delivery model LAPSUS-D. Geomorphology, vol. 212, pp. 97-107. Levin N., Levental

Thermal co-treatment of combustible hazardous waste and waste incineration fly ash in a rotary kiln.

Science.gov (United States)

Huber, Florian; Blasenbauer, Dominik; Mallow, Ole; Lederer, Jakob; Winter, Franz; Fellner, Johann

2016-12-01

As current disposal practices for municipal solid waste incineration (MSWI) fly ash are either associated with significant costs or negative environmental impacts, an alternative treatment was investigated in a field scale experiment. Thereto, two rotary kilns were fed with hazardous waste, and moistened MSWI fly ash (water content of 23%) was added to the fuel of one kiln with a ratio of 169kg/Mg hazardous waste for 54h and 300kg/Mg hazardous waste for 48h while the other kiln was used as a reference. It was shown that the vast majority (>90%) of the inserted MSWI fly ash was transferred to the bottom ash of the rotary kiln. This bottom ash complied with the legal limits for non-hazardous waste landfills, thereby demonstrating the potential of the investigated method to transfer hazardous waste (MSWI fly ash) into non-hazardous waste (bottom ash). The results of a simple mixing test (MSWI fly ash and rotary kiln bottom ash have been mixed accordingly without thermal treatment) revealed that the observed transformation of hazardous MSWI fly ash into non-hazardous bottom ash during thermal co-treatment cannot be referred to dilution, as the mixture did not comply with legal limits for non-hazardous waste landfills. For the newly generated fly ash of the kiln, an increase in the concentration of Cd, K and Pb by 54%, 57% and 22%, respectively, was observed. In general, the operation of the rotary kiln was not impaired by the MSWI fly ash addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of carbonation on the leaching of organic carbon and of copper from MSWI bottom ash.

Science.gov (United States)

Arickx, S; De Borger, V; Van Gerven, T; Vandecasteele, C

2010-07-01

In Flanders, the northern part of Belgium, about 31% of the produced amount of MSWI bottom ash is recycled as secondary raw material. In view of recycling a higher percentage of bottom ash, a particular bottom ash fraction (Ø 0.1-2mm) was studied. As the leaching of this bottom ash fraction exceeds some of the Flemish limit values for heavy metals (with Cu being the most critical), treatment is required. Natural weathering and accelerated carbonation resulted in a significant decrease of the Cu leaching. Natural weathering during 3 months caused a decrease of Cu leaching to <50% of its original value, whereas accelerated carbonation resulted in an even larger decrease (to ca. 13% of its initial value) after 2 weeks, with the main decrease taking place within the first 48 h. Total organic carbon decreased to ca. 70% and 55% of the initial concentration in the solid phase, and to 40% and 25% in the leachate after natural weathering and after accelerated carbonation, respectively. In the solid material the decrease of the Hy fraction was the largest, the FA concentration remained essentially constant. The decrease of FA in the leachate can be attributed partly to an enhanced adsorption of FA to Fe/Al (hydr)oxides, due to the combined effect of a pH decrease and the neoformation of Al (hydr)oxides (both due to carbonation). A detailed study of adsorption of FA to Fe/Al (hydr)oxides showed that significant adsorption of FA occurs, that it increases with decreasing pH and started above pH 12 for Fe (hydr)oxides and around 10 for Al (hydr)oxides. Depending whether FA or Hy are considered the controlling factor in enhanced Cu leaching, the decreasing FA or Hy in the leachate explains the decrease in the Cu leaching during carbonation. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Regenerable cobalt oxide loaded magnetosphere catalyst from fly ash for mercury removal in coal combustion flue gas.

Science.gov (United States)

Yang, Jianping; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

2014-12-16

To remove Hg(0) in coal combustion flue gas and eliminate secondary mercury pollution of the spent catalyst, a new regenerable magnetic catalyst based on cobalt oxide loaded magnetospheres from fly ash (Co-MF) was developed. The catalyst, with an optimal loading of 5.8% cobalt species, attained approximately 95% Hg(0) removal efficiency at 150 °C under simulated flue gas atmosphere. O2 could enhance the Hg(0) removal activity of magnetospheres catalyst via the Mars-Maessen mechanism. SO2 displayed an inhibitive effect on Hg(0) removal capacity. NO with lower concentration could promote the Hg(0) removal efficiency. However, when increasing the NO concentration to 300 ppm, a slightly inhibitive effect of NO was observed. In the presence of 10 ppm of HCl, greater than 95.5% Hg(0) removal efficiency was attained, which was attributed to the formation of active chlorine species on the surface. H2O presented a seriously inhibitive effect on Hg(0) removal efficiency. Repeated oxidation-regeneration cycles demonstrated that the spent Co-MF catalyst could be regenerated effectively via thermally treated at 400 °C for 2 h.

Evolution of coal ash solidification properties with disposal site depth and age, 'Gacko' Thermal power plant case

Directory of Open Access Journals (Sweden)

Knežević Dinko

2017-01-01

Full Text Available Ash with high calcium content is produced by coal combusting in 'Gacko' thermal power plant (Bosnia and Herzegovina. Result of controlled mixture of water and ash is spontaneous ash solidification on disposal site. Speed and solidification efficiency depends on content of calcium-oxide in ash and water: ash mass ratio, which was determined by previous research. Mass ratio that was chosen as the most suitable ratio for industrial usage (roughly was 1:1. Samples of ash of different age were taken after 6.5 years of exploitation and their chemical, physical, mineralogical and geotechnical characteristics were analyzed. Disposed ash was stratified and very heterogeneous. It was shown that great impact on solidification process in practice have climate conditions, proper handling slurry processing, work continuity and disposal site preparation. Great impact of water is noticed which is, because of its water permeability filtrated into lower layers and significantly alters it characteristic.

Analysis of Physical Properties and Mineralogical of Pyrolysis Tires Rubber Ash Compared Natural Sand in Concrete material

Science.gov (United States)

Syamir Senin, Mohamad; Shahidan, Shahiron; Syazani Leman, Alif; Izzati Raihan Ramzi Hannan, Nurul

2016-11-01

Waste tires pose significant health and environmental concerns if not recycled or discarded properly. At the same time, natural sand is becoming scarcer and costlier due to its non-availability. Waste tires as fine aggregate can be an economical and sustainable alternative to the natural sand. Recent years, the interest on recycling waste tires into civil engineering applications by the researchers has increased. In this research, the chemical and physical properties of the tires rubber ash and the natural sand have been analysed. The densities of the rubber ash are lower than the natural sand. Rubber ash had finer particle size compared to the natural sand. Almost all chemical in the natural sand had in rubber ash with the additional sulphur trioxide and zinc oxide in the rubber ash, made the rubber ash better than natural sand. Rubber ash seems to be a suitable material to use in concrete as sand replacement.

Relationships between waste physicochemical properties, microbial activity and vegetation at coal ash and sludge disposal sites.

Science.gov (United States)

Woch, Marcin W; Radwańska, Magdalena; Stanek, Małgorzata; Łopata, Barbara; Stefanowicz, Anna M

2018-06-11

The aim of the study was to assess the relationships between vegetation, physicochemical and microbial properties of substrate at coal ash and sludge disposal sites. The study was performed on 32 plots classified into 7 categories: dried ash sedimentation ponds, dominated by a grass Calamagrostis epigejos (AH-Ce), with the admixture of Pinus sylvestris (AH-CePs) or Robinia pseudoacacia (AH-CeRp), dry ash landfill dominated by Betula pendula and Pinus sylvestris (AD-BpPs) or Salix viminalis (AD-Sv) and coal sludge pond with drier parts dominated by Tussilago farfara (CS-Tf) and the wetter ones by Cyperus flavescens (CS-Cf). Ash sites were covered with soil layer imported as a part of technical reclamation. Ash had relatively high concentrations of some alkali and alkaline earth metals, Mn and pH, while coal sludge had high water and C, S, P and K contents. Concentrations of heavy metals were lower than allowable limits in all substrate types. Microbial biomass and, particularly, enzymatic activity in ash and sludge were generally low. The only exception were CS-Tf plots characterized by the highest microbial biomass, presumably due to large deposits of organic matter that became available for aerobic microbial biomass when water level fell. The properties of ash and sludge adversely affected microbial biomass and enzymatic activity as indicated by significant negative correlations between the content of alkali/alkaline earth metals, heavy metals, and macronutrients with enzymatic activity and/or microbial biomass, as well as positive correlations of these parameters with metabolic quotient (qCO 2 ). Plant species richness and cover were relatively high, which may be partly associated with alleviating influence of soil covering the ash. The effect of the admixture of R. pseudoacacia or P. sylvestris to stands dominated by C. epigejos was smaller than expected. The former species increased NNH 4 , NNO 3 and arylsulfatase activity, while the latter reduced activity of

Magnetism and magnetic mineralogy of ash flow tuffs from Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Schlinger, C.M.; Veblen, D.R.; Rosenbaum, J.G.

1991-01-01

The magnetic susceptibility χ and remanent magnetization of an ash flow sheet are profoundly influenced by cooling history after emplacement. Maxima and minima in χ measured along profiles at Yucca Mountain, Nevada, identify persistent magnetic marker horizons within vitric portions of the Tiva Canyon and underlying Topopah Spring Members of the Paintbrush Tuff. The observed stratigraphic changes in magnetic properties reflect variations in amounts and mineralogy of Fe-Ti oxide phenocrysts, and the presence, shape, size, and mineralogy of magnetic Fe-oxide microcrystals that precipitated at high temperature after emplacement of each sheet. The size variations of the precipitated Fe-oxides, which were established using transmission electron microscopy (TEM) and petrographic observation, are consistent both with variations in magnetic susceptibility measured at the outcrop and with variations in the intensity of remanent magnetization. Several interpretations of the shape anisotropy of the precipitated Fe-oxide are possible, including growth by a dislocation mechanism. Additionally, the observed elongation of precipitated microcrystals is consistent with theoretical predictions for growth in a uniaxial stress field. Susceptibility variations as established at the outcrop, as well as in the borehole, offer a potentially useful tool for stratigraphic correlation of ash flow sheets

Partial oxidation process

International Nuclear Information System (INIS)

Najjar, M.S.

1987-01-01

A process is described for the production of gaseous mixtures comprising H/sub 2/+CO by the partial oxidation of a fuel feedstock comprising a heavy liquid hydrocarbonaceous fuel having a nickel, iron, and vanadium-containing ash or petroleum coke having a nickel, iron, and vanadium-containing ash, or mixtures thereof. The feedstock includes a minimum of 0.5 wt. % of sulfur and the ash includes a minimum of 5.0 wt. % vanadium, a minimum of 0.5 ppm nickel, and a minimum of 0.5 ppm iron. The process comprises: (1) mixing together a copper-containing additive with the fuel feedstock; wherein the weight ratio of copper-containing additive to ash in the fuel feedstock is in the range of about 1.0-10.0, and there is at least 10 parts by weight of copper for each part by weight of vanadium; (2) reacting the mixture from (1) at a temperature in the range of 2200 0 F to 2900 0 F and a pressure in the range of about 5 to 250 atmospheres in a free-flow refactory lined partial oxidation reaction zone with a free-oxygen containing gas in the presence of a temperature moderator and in a reducing atmosphere to produce a hot raw effluent gas stream comprising H/sub 2/+CO and entrained molten slag; and where in the reaction zone and the copper-containing additive combines with at least a portion of the nickel and iron constituents and sulfur found in the feedstock to produce a liquid phase washing agent that collects and transports at least a portion of the vanadium-containing oxide laths and spinels and other ash components and refractory out of the reaction zone; and (3) separating nongaseous materials from the hot raw effluent gas stream

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 (...

488-D Ash Basin Vegetative Cover Treatibility Study

Energy Technology Data Exchange (ETDEWEB)

Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

2003-01-01

The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

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.

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.

Overview of hydraulic ash and slag transport in the Power Plantt 'Oslomej': Macedonia

Directory of Open Access Journals (Sweden)

Cvetanoski Radomir K.

2017-01-01

Full Text Available AD ELEM Skopje Subsidiary REK 'Oslomej' s. Oslomej is a part of the energy system with an installed power of 125 MW and the net average annual production of 500 GWh of electricity. The basic fuel is coal with an average of 7600 KJ/kg. Coal from the mine is provided Oslomej - west and old mine (Oslomej-east wherein 2009. excavated 1.156.709 t. The main aim of the project is solving environmental problems in Power Plant Oslomej and its surrounding area that creates the existing system of transport and disposal of ash and slag (transport of moist ash by conveyor belt at an open landfill, so the main task of this Project is introducing new technologies of transport and disposal of ash and slag in the form of hydro mixtures.

Simulating intracrater ash recycling during mid-intensity explosive activity: high temperature laboratory experiments on natural basaltic ash

Science.gov (United States)

D'Oriano, Claudia; Pompilio, Massimo; Bertagnini, Antonella; Cioni, Raffaello; Pichavant, Michel

2010-05-01

Direct observations of mid-intensity eruptions, in which a huge amount of ash is generated, indicate that ash recycling is quite common. The recognition of juvenile vs. recycled fragments is not straightforward, and no unequivocal, widely accepted criteria exist to support this. The presence of recycled glassy fragments can hide primary magmatic information, introducing bias in the interpretations of the ongoing magmatic and volcanic activity. High temperature experiments were performed at atmospheric pressure on natural samples to investigate the effects of reheating on morphology, texture and composition of volcanic ash. Experiments simulate the transformation of juvenile glassy fragments that, falling into the crater or in the upper part of the conduit, are recycled by following explosions. Textural and compositional modifications obtained in laboratory are compared with similar features observed in natural samples in order to identify some main general criteria to be used for the discrimination of recycled material. Experiments were carried out on tephra produced during Strombolian activity, fire fountains and continuous ash emission at Etna, Stromboli and Vesuvius. Coarse glassy clasts were crushed in a nylon mortar in order to create an artificial ash, and then sieved to select the size interval of 1-0.71 mm. Ash shards were put in a sealed or open quartz tube, in order to prevent or to reproduce effects of air oxidation. The tube was suspended in a HT furnace at INGV-Pisa and kept at different temperatures (up to to 1110°C) for increasing time (0.5-12 hours). Preliminary experiments were also performed under gas flux conditions. Optical and electron microscope observations indicate that high temperature and exposure to the air induce large modifications on clast surface, ranging from change in color, to incipient plastic deformation till complete sintering. Significant change in color of clasts is strictly related to the presence of air, irrespective of

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.

Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

Science.gov (United States)

Bodi, Merche B.; Martin, Deborah; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Cerda, Artemi; Mataix-Solera, Jorge

2014-01-01

Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The homogeneity and thickness of the ash layer can vary substantially in space and time and reported average thicknesses range from close to 0 to 50 mm. Ash is a highly mobile material that, after its deposition, may be incorporated into the soil profile, redistributed or removed from a burned site within days or weeks by wind and water erosion to surface depressions, footslopes, streams, lakes, reservoirs and, potentially, into marine deposits.Research on the composition, properties and effects of ash on the burned ecosystem has been conducted on material collected in the field after wildland and prescribed fires as well as on material produced in the laboratory. At low combustion completeness (typically T  450 °C), most organic carbon is volatized and the remaining mineral ash has elevated pH when in solution. It is composed mainly of calcium, magnesium, sodium, potassium, silicon and phosphorous in the form of inorganic carbonates, whereas at T > 580 °C the most common forms are oxides. Ash produced under lower combustion completeness is usually darker, coarser, and less dense and has a higher saturated hydraulic conductivity than ash with higher combustion completeness, although physical reactions with CO2 and when moistened produce further changes in ash characteristics.As a new

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.

Thermo-mechanical properties and microfabric of fly ash-stabilized gold tailings.

Science.gov (United States)

Lee, Joon Kyu; Shang, Julie Q; Jeong, Sangseom

2014-07-15

This paper studies the changes in thermal conductivity, temperature, and unconfined compressive strength of gold tailings and fly ash mixtures during the curing period of 5 days. The microfabric of the cured mixtures was investigated with mercury intrusion porosimetry (MIP). The mixture samples were prepared at their maximum dry unit weight and optimum moisture content. Effect of adding fly ash to gold tailings (i.e., 0, 20, and 40% of the dry weight of tailings) was examined, and a comparison was made on samples prepared at the same fly ash content by replacing gold tailings with humic acid (i.e., gold tailings and humic acid ratios of 100:0, 90:10, and 80:20 by weight) or by varying pore fluid chemistry (i.e., water and salt solutions of 1M NaCl and CaCl2). The results show that the initial thermal conductivity of the samples is sensitive to the mixture proportion and a declination in the thermal conductivity is observed due to hydration of fly ash and evaporation. Inclusion of fly ash and salts into gold tailings improves the unconfined compressive strength but the presence of humic acid in samples leads to the decrease of the strength. MIP results reveal the pore structure changes associated with the packing states of the samples that reflect the influential factors considered. Copyright © 2014 Elsevier B.V. All rights reserved.

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)

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.

Cd toxicity in Ash amended to plantations; the dilemma of different answers at different levels of description

DEFF Research Database (Denmark)

Christensen, Søren; Ekelund, Flemming; Kjøller, Rasmus

2018-01-01

. Other more abundant cations like Zn regulate Cd uptake. Mycorrhiza reduce Cd uptake in several plants. In barley Cd gradually decrease from root via stem to seeds. In conclusion for ash amounts up to 10 t/ha, we do not find metal toxicity of ash or evidence for bioaccumulation of metals in soil...... growth, equally because of the pH increase and the nutrients added. The pH increase stimulates decomposition activity. Soil carbon availability is not permanently increased with ash amendment, however, which may suggest that decomposition increase is coupled to primary production increase. Plantation....... Wood ash increase plantation soil Cd, and so did Cd in grass although at a very low level, Cd in lichens and Cd in the small biomass of earthworms. The toxicity of Cd is regulated by metal binding to soil being several orders of magnitude lower than in pure liquid. Ash is toxic towards microarthropods...

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.

Changes in SOM composition and stability to microbial degradation over time in response to wood chip ash fertilisation

DEFF Research Database (Denmark)

Hansen, Mette; Saarsalmi, Anna; Peltre, Clement

2016-01-01

spectroscopy (FTIR-PAS) analysis of bulk soil samples. Ash fertilisation of forest soils affected SOM composition in the O-horizon, but not in the top 5 cm of the mineral soil. The pH and biodegradability of SOM were increased in the O-horizon. The changes in SOM composition consisted of enrichment of Fe...... in Denmark, where ash had been spread at different times. Changes in SOM biodegradability were estimated based on an incubation experiment, expressed as percentage of initial carbon. Changes in SOM composition were characterised using thermal analysis and Fourier transform mid-infrared photoacoustic......- and Al-oxides/hydroxides, depletion of carboxylic and aromatic groups and lower thermal stability in soils with older and greater ash application. Ash fertilisation increased soil pH, either right after ash application or through a buffering effect of the ash on acidification caused by decomposing...

The chemical composition of tertiary Indian coal ash and its

Indian Academy of Sciences (India)

In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study ...

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....

Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview.

Science.gov (United States)

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

2001-05-01

Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New regulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal. Over a few decades a number of studies have been carried out on the utilization of wood ashes in agriculture and forestry as an alternative method for disposal. Because of their properties and their influence on soil chemistry the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its physical, chemical and mineralogical characteristics, its effect on soil properties, on the availability of nutrient elements and on the growth and chemical composition of crops and trees, as well as its impact on the environment.

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.

A novel hydrothermal method to convert incineration ash into pollucite for the immobilization of a simulant radioactive cesium

Energy Technology Data Exchange (ETDEWEB)

Jing, Zhenzi, E-mail: zzjing@tongji.edu.cn [Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University, 4800 Cao’an Road, Shanghai 201804 (China); Hao, Wenbo; He, Xiaojun; Fan, Junjie; Zhang, Yi; Miao, Jiajun [Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University, 4800 Cao’an Road, Shanghai 201804 (China); Jin, Fangming [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2016-04-05

Highlights: • Incineration ash could be converted hydrothermally to pollucite to immobilize Cs. • Pollucite could be synthesized readily with a wide range of Cs/Si ratios. • With Ca(OH){sub 2} added, a tough pollucite could be used to solidify Cs-polluted RHA. • Leaching results showed that the amount of Cs leached from specimen was very low. - Abstract: The Fukushima nuclear accident in Japan on March 11, 2011 produced huge amounts of Cs-polluted incineration ashes; conventional solidification methods seem unsuitable for the treatment of large amounts of Cs-polluted ashes. A novel hydrothermal method was developed to directly convert Cs-polluted incineration ash (rice husk ash) into pollucite to immobilize Cs in its crystal structure in situ. Results revealed that pollucite could be synthesized readily over a wide range of added Cs (Cs/Si = 0.2–0.6); the addition of more Cs (Cs/Si ≥ 0.5) caused the formation of a small amount of cesium aluminosilicate (CsAlSiO{sub 4}), which exhibits poor immobilization behavior for Cs. Pollucite could be formed even for a short curing time (1 h) or at a low curing temperature (150 °C). However, a high curing temperature or a long curing time favored the formation of a pure pollucite. With the added calcium hydroxide, a tough specimen with a flexural strength of approximately 22 MPa could be obtained, which suggested that this technology may be applied directly to the solidification of Cs-polluted incineration ashes. Hydrogarnet and tobermorite formations enhanced the strength of the solidified specimens, and meanwhile the formed pollucite was present in a matrix steadily. Leaching test demonstrated that the amount of Cs that leached from the synthesized specimens was very low (0.49 × 10{sup −5}–2.31 × 10{sup −5}) and even lower than that from the reference hollandite-rich synroc (2.0 × 10{sup −2}), although a higher content of Cs was found in the synthesized pollucite specimens (6.0–31.7%) than in the

Leaching of wood ash - Laboratory and field studies; Lakning av vedaska - Laboratorie- och faeltstudier

Energy Technology Data Exchange (ETDEWEB)

Larsson, Per-Erik

2012-02-15

High forest production leads to diminishing amounts of base cations and micro nutrients in forest soils. This is due to uptake in, and harvest of, the trees. Losses can be compensated for by spreading stabilized wood ash on the forest ground, which means recycling of base cations and micro nutrients. Chemical composition of wood ash can easily be described by standard methods in the laboratory. However, this does not include the process of leaching in nature, such as which components and leaching rate for different compounds. During field conditions several factors are added, which are not available in the laboratory. After almost 10 years in the forest soils there still remains large quantities of the original product. Only 10-30 % of the wood ash products and 5 % of the lime product has been leached. In the laboratory study the leached amount was slightly larger, at the most 35 % for wood ash and 20 % for lime. Both studies indicate long time for weathering of the products in forest soils. Slower leaching rate from pellets of wood ash compared to leaching rate from crushed wood ash in the laboratory study is not verified by the field study. This indicates limited possibilities to control rates of leaching in the environment

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...

Characterization of ash melting behaviour at high temperatures under conditions simulating combustible solid waste gasification.

Science.gov (United States)

Niu, Miaomiao; Dong, Qing; Huang, Yaji; Jin, Baosheng; Wang, Hongyan; Gu, Haiming

2018-05-01

To achieve high-temperature gasification-melting of combustible solid waste, ash melting behaviour under conditions simulating high-temperature gasification were studied. Raw ash (RA) and gasified ash (GA) were prepared respectively by waste ashing and fluidized bed gasification. Results of microstructure and composition of the two-ash indicated that GA showed a more porous structure and higher content of alkali and alkali earth metals among metallic elements. Higher temperature promoted GA melting and could reach a complete flowing state at about 1250°C. The order of melting rate of GA under different atmospheres was reducing condition > inert condition > oxidizing condition, which might be related to different existing forms of iron during melting and different flux content with atmosphere. Compared to RA, GA showed lower melting activity at the same condition due to the existence of an unconverted carbon and hollow structure. The melting temperature for sufficient melting and separation of GA should be at least 1250°C in this work.

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.

Gypsum amendment to soil can reduce selenium uptake by alfalfa grown in the presence of coal fly ash

International Nuclear Information System (INIS)

Arthur, M.A.; Rubin, G.; Woodbury, P.B.; Weinstein, L.H.

1993-01-01

Experiments in the field and greenhouse were conducted in the presence of coal fly ash to determine whether gypsum can reduce Se concentration in alfalfa (Medicago sativa L.). In the field experiment, conducted at a coal fly ash landfill, 11.2 t ha -1 gypsum was applied to soil as a top dressing to test the effect of gypsum in reducing selenium (Se) concentration in aboveground plant tissue. There were four treatment combinations of gypsum over a two year period, 1990, and 1991: (0, 0), (0, 11.2) (11.2, 0) and (11.2, 11.2). In 1991, the Se concentration was lower in alfalfa grown with gypsum, regardless of whether the gypsum was applied in both years or in only one year, indicating that the effect of gypsum application in the first year persisted into the second year. Since there was no increase in aboveground biomass with added gypsum, differences in Se concentration reflect a competitive interaction between S and Se. In the greenhouse experiment, 12 soil treatments were tested: three levels of fly ash (0, 10 and 20%) in combination with each of four levels of gypsum (0, 2.5, 5 and 7.5%). The Se concentration in alfalfa grown in 10% fly ash declined linearly with increasing gypsum dose, resulting in a reduction in Se concentration of 0.04 ± 0.02 μg g -1 for each 1% gypsum added for the first harvest and 0.06 ± 0.03 μg g -1 for each 1% gypsum added in the second harvest. Based on these results, gypsum may prove useful as a management tool to reduce the uptake of Se by plants growing on coal fly ash landfills

Synthesis of Zeolite-X from Bottom Ash for H2 Adsorption

Science.gov (United States)

Kurniawan, R. Y.; Romadiansyah, T. Q.; Tsamarah, A. D.; Widiastuti, N.

2018-01-01

Zeolite-X was synthesized from bottom ash power plant waste using fusion method on air atmosphere. The fused product dissolved in demineralized water and aluminate solution was added to adjust the SiO2/Al2O3 molar ratio gel prior hydrothermal process. The synthesis results were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR). The results showed that the zeolite-X has a high crystallinity with octahedral particle. The pure-form zeolite-X then was characterized and tested for H2 gas adsorption by gravimetric method to determine the H2 gas adsorption capacity of zeolite-X from bottom ash and it was compared to synthetic zeolite-X.

Shedding of ash deposits

DEFF Research Database (Denmark)

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

2009-01-01

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

Pengaruh Kombinasi Fly Ash dan Bottom Ash sebagai Bahan Substitusi pada Campuran Beton terhadap Sifat Mekanis

OpenAIRE

Yahya, Tengku Tantoni; Kurniawandy, Alex; Djauhari, Zulfikar

2017-01-01

Fly ash and bottom ash were waste that generated from the power plant burning coal process. Fly ash and bottom ash has the potential to be developed as a basic ingredient in concrete composites. This research aimed to obtain the properties of fresh concrete and hard concrete of the combined effect of fly ash and bottom ash as a substitute ingredient in composite concrete. This research has examined the influence of a combination of waste fly ash and bottom ash to the compressive strength of a...

Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash

Energy Technology Data Exchange (ETDEWEB)

Marchini, T.; Magnani, N.D. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Paz, M.L. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Vanasco, V. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Tasat, D. [CESyMA, Facultad de Ciencia Tecnología, Universidad Nacional de General San Martín, Martín de Irigoyen 3100, 1650 San Martín, Buenos Aires (Argentina); González Maglio, D.H. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); and others

2014-01-15

It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5 h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1 h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3 h. The onset of an adaptive response was observed at 5 h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation. - Highlights: • An acute exposure to ROFA triggers the occurrence of systemic oxidative stress. • Changes in plasmatic oxidative stress markers appear as early as 1 h after exposure. • ROFA induces proinflammatory cytokines release and intravascular leukocyte activation. • PMN

Synergistic effect of biogenic Fe3+ coupled to S° oxidation on simultaneous bioleaching of Cu, Co, Zn and As from hazardous Pyrite Ash Waste.

Science.gov (United States)

Panda, Sandeep; Akcil, Ata; Mishra, Srabani; Erust, Ceren

2017-03-05

Pyrite ash, a waste by-product formed during roasting of pyrite ores, is a good source of valuable metals. The waste is associated with several environmental issues due to its dumping in sea and/or land filling. Although several other management practices are available for its utilization, the waste still awaits and calls for an eco-friendly biotechnological application for metal recovery. In the present study, chemolithotrophic meso-acidophilic iron and sulphur oxidisers were evaluated for the first time towards simultaneous mutli-metal recovery from pyrite ash. XRD and XRF analysis indicated higher amount of Hematite (Fe 2 O 3 ) in the sample. ICP-OES analysis indicated concentrations of Cu>Zn>Co>As that were considered for bioleaching. Optimization studies indicated Cu - 95%, Co - 97%, Zn - 78% and As - 60% recovery within 8days at 10% pulp density, pH - 1.75, 10% (v/v) inoculum and 9g/L Fe 2+ . The productivity of the bioleaching system was found to be Cu - 1696ppm/d (12% dissolution/d), Co - 338ppm/d (12.2% dissolution/d), Zn k 576ppm/d (9.8% dissolution/d) and As - 75ppm/d (7.5% dissolution/d). Synergistic actions for Fe 2+ - S° oxidation by iron and sulphur oxidisers were identified as the key drivers for enhanced metal dissolution from pyrite ash sample. Copyright © 2016 Elsevier B.V. All rights reserved.

Trace element toxicity in VA mycorrhizal cucumber grown on weathered coal fly ash

Energy Technology Data Exchange (ETDEWEB)

Dosskey, M.G.; Adriano, D.C. (University of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.)

1993-11-01

Mycorrhizal colonization is widely recognized as enhancing plant growth on severely disturbed sites. A greenhouse pot experiment was conducted to determine if inoculation with vesicular-arbuscular mycorrhizal (VAM) fungi will enhance vegetation establishment on abandoned coal fly ash basinss, Spores of Glomus intraradices (Schenck and Smith) and Glomus etunicatum (Becker and Gerdemann) were added to weathered precipitator ash (EC-0.91 dSm[sup -1], pH 5.0) and to a pasteurized soils of the same pH (Grossarenic Paleudult, 92% sand, 1% organic matter). Some soil and ash were left unamended as non-mycorrhizal controls. Cucumber (Cucumis sativus L. cv. Poinsette 76) seeds were sown, watered regularly, and fertilized periodically with macronutrient solution. By 8 weeks all ash-grown plants exhibited smaller leaves with leaf margin curl and necrosis, and plant biomass was significantly less (0.75x) than soil-grown plants. Based on analysis of 18 elements in plant tissues, toxicity to B, Mn, or Zn could have caused growth suppression, confirming trace element problems for plant growth on fly ash. For plants grown on fly ash, G. etunicatum was the only fungus that colonized roots (20% of root length reduced from 67% on soil) and it suppressed plant growth to 0.80 x that of uninoculated ash-grown plants. Correspondingly, shoot Zn concentration in G. etunicatum-inoculated plants was 3.5 x higher than in uninoculated plants and at generally toxic levels (273 mg kg[sup -1]). Glomus etunicatum had no other significant effects on elemental concentrations. These results indicate that VAM colonization in acid, weathered fly ash suppressed plant growth by facilitating uptake of Zn to toxic levels, and implies a limitation to successful use of VAM for vegetation establishment on abandoned coal fly ash basins.

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...

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

Science.gov (United States)

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

2016-06-01

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

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.

Improving the Bearing Strength of Sandy Loam Soil Compressed Earth Block Bricks Using Sugercane Bagasse Ash

Directory of Open Access Journals (Sweden)

Ramadhan W. Salim

2014-06-01

Full Text Available The need for affordable and sustainable alternative construction materials to cement in developing countries cannot be underemphasized. Compressed Earth Bricks have gained acceptability as an affordable and sustainable construction material. There is however a need to boost its bearing capacity. Previous research show that Sugarcane Bagasse Ash as a soil stabilizer has yielded positive results. However, there is limited research on its effect on the mechanical property of Compressed Earth Brick. This current research investigated the effect of adding 3%, 5%, 8% and 10% Sugarcane Bagasse Ash on the compressive strength of compressed earth brick. The result showed improvement in its compressive strength by 65% with the addition of 10% Sugarcane Bagasse Ash.

Catalytic ozonation of ammonia using biomass char and wood fly ash.

Science.gov (United States)

Kastner, James R; Miller, Joby; Kolar, Praveen; Das, K C

2009-05-01

Catalytic ozonation of gaseous ammonia was investigated at room temperature using wood fly ash (WFA) and biomass char as catalysts. WFA gave the best results, removing ammonia (11 ppmv NH(3), 45% conversion) at 23 degrees C at a residence time of 0.34 s, using 5 g of catalyst or ash at the lowest ozone concentration (62 ppmv). Assuming pseudo zero order kinetics in ozone, a power rate law of -r(NH3) = 7.2 x 10(-8) C(NH3)(0.25) (r, mol g(-1)s(-1), C(NH3)molL(-1)) was determined at 510 ppmv O(3) and 23 degrees C for WFA. Water vapor approximately doubled the oxidation rate using WFA and catalytic ozonation activity was not measured for the char without humidifying the air stream. Overall oxidation rates using the crude catalysts were lower than commercial catalysts, but the catalytic ozonation process operated at significantly lower temperatures (23 vs. 300 degrees C). Nitric oxide was not detected and the percentage of NO(2) formed from NH(3) oxidation ranged from 0.3% to 3% (v/v), with WFA resulting in the lowest NO(2) level (at low O(3) levels). However, we could not verify that N(2)O was not formed, so further research is needed to determine if N(2) is the primary end-product. Additional research is required to develop techniques to enhance the oxidation activity and industrial application of the crude, but potentially inexpensive catalysts.

Environmental Benefit Assessment for the Carbonation Process of Petroleum Coke Fly Ash in a Rotating Packed Bed.

Science.gov (United States)

Pei, Si-Lu; Pan, Shu-Yuan; Li, Ye-Mei; Chiang, Pen-Chi

2017-09-19

A high-gravity carbonation process was deployed at a petrochemical plant using petroleum coke fly ash and blowdown wastewater to simultaneously mineralized CO 2 and remove nitrogen oxides and particulate matters from the flue gas. With a high-gravity carbonation process, the CO 2 removal efficiency was found to be 95.6%, corresponding to a capture capacity of 600 kg CO 2 per day, at a gas flow rate of 1.47 m 3 /min under ambient temperature and pressure. Moreover, the removal efficiency of nitrogen oxides and particulate matters was 99.1% and 83.2%, respectively. After carbonation, the reacted fly ash was further utilized as supplementary cementitious materials in the blended cement mortar. The results indicated that cement with carbonated fly ash exhibited superior compressive strength (38.1 ± 2.5 MPa at 28 days in 5% substitution ratio) compared to the cement with fresh fly ash. Furthermore, the environmental benefits for the high-gravity carbonation process using fly ash were critically assessed. The energy consumption of the entire high-gravity carbonation ranged from 80 to 169 kWh/t-CO 2 (0.29-0.61 GJ/t-CO 2 ). Compared with the scenarios of business-as-usual and conventional carbon capture and storage plant, the economic benefit from the high-gravity carbonation process was approximately 90 and 74 USD per ton of CO 2 fixation, respectively.

Chemical, microbial and physical properties of manufactured soils produced by co-composting municipal green waste with coal fly ash

Energy Technology Data Exchange (ETDEWEB)

Belyaeva, O.N.; Haynes, R.J. [University of Queensland, St Lucia, Qld. (Australia)

2009-11-15

Increasing proportions of coal fly ash were co-composted with municipal green waste to produce manufactured soil for landscaping use. Only the 100% green waste treatment reached a thermophilic composting phase ({ge} 50{sup o}C) which lasted for 6 days. The 25% and 50% ash treatments reached 36-38{sup o}C over the same period while little or no self-heating occurred in the 75% and 100% ash treatments. Composted green waste had a low bulk density and high total and macro-porosity. Addition of 25% ash to green waste resulted in a 75% increase in available water holding capacity. As the proportions of added ash in the composts increased, the organic C, soluble C, microbial biomass C, basal respiration and activities of beta-glucosidase, L-asparaginase, alkali phosphatase and arylsulphatase enzymes in the composted products all decreased. It could be concluded that addition of fly ash to green waste at a proportion higher than 25% did not improve the quality parameters of manufactured soil.

Graphene/fly ash geopolymeric composites as self-sensing structural materials

Energy Technology Data Exchange (ETDEWEB)

Saafi, Mohamed; Fung, Jason; Rahman, Mahbubur [Department of Civil and Environmental Engineering, University of Strathclyde, G4 0NG (United Kingdom); Tang, Leung [Agilent Technologies, Mobile Measurement Group, EH12 9DJ (United Kingdom); Sillars, Fiona [Advanced Materials Research Laboratory, University of Strathclyde, G4 0NG (United Kingdom); Liggat, John [Department of Pure and Applied Chemistry, University of Strathclyde, G4 0NG (United Kingdom); Zhou, Xiangming [School of Engineering, Brunel University, UB8 3PH (United Kingdom)

2014-06-15

The reduction of graphene oxide during the processing of fly ash-based geopolymers offers a completely new way of developing low-cost multifunctional materials with significantly improved mechanical and electrical properties for civil engineering applications such as bridges, buildings and roads. In this paper, we present for the first time the self-sensing capabilities of fly ash-based geopolymeric composites containing in situ reduced graphene oxide (rGO). Geopolymeric composites with rGO concentrations of 0.0, 0.1 and 0.35% by weight were prepared and their morphology and conductivity were determined. The piezoresistive effect of the rGO-geopolymeric composites was also determined under tension and compression. The Fourier transform infrared spectroscopy (FTIR) results indicate that the rGO sheets can easily be reduced during synthesis of geopolymers due to the effect of the alkaline solution on the functional groups of GO. The scanning electron microscope (SEM) images showed that the majority of pores and voids within the geopolymers were significantly reduced due to the addition of rGO. The rGO increased the electrical conductivity of the fly ash-based rGO-geopolymeric composites from 0.77 S m{sup −1} at 0.0 wt% to 2.38 S m{sup −1} at 0.35 wt%. The rGO also increased the gauge factor by as much as 112% and 103% for samples subjected to tension and compression, respectively.

Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash

International Nuclear Information System (INIS)

Ivan Diaz-Loya, E.; Allouche, Erez N.; Eklund, Sven; Joshi, Anupam R.; Kupwade-Patil, Kunal

2012-01-01

Highlights: ► Incinerator fly ash (IFA) is added to an alkali activated coal fly ash (CFA) matrix. ► Means of stabilizing the incinerator ash for use in construction applications. ► Concrete made from IFA, CFA and IFA-CFA mixes was chemically characterized. ► Environmentally friendly solution to IFA disposal by reducing its toxicity levels. - Abstract: Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA’s Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson’s ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases even below the reporting limit. The leachable Chromium was reduced from 0.153 down to 0.0045 mg

INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

2000-11-01

This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

Elution behavior of heavy metals from cement solidified products of incinerated ash waste - 59102

International Nuclear Information System (INIS)

Meguro, Yoshihiro; Kawato, Yoshimi; Nakayama, Takuya; Tomioka, Osamu; Mitsuda, Motoyuki

2012-01-01

A method, in which incinerated ash is solidified with a cement material, has been developed to dispose radioactive incinerated ash waste. In order to bury the solidified product, it is required that elution of hazardous heavy metals included in the ash from the solidified products is inhibited. In this study, the elution behavior of the heavy metals from the synthetic solidified products, which included Pb(II), Cd(II), and Cr(VI) and were prepared using ordinary portland cement (OPC), blast furnace slag cement (BFS), or a cement material that showed low alkalinity (LA-Cement), was investigated. Several chemicals and materials were added as additive agents to prevent the elution of the heavy metals. When OPC was used, Cd elution was inhibited, but Pb and Cr were not enough even using the additive agent examined. FeSO 4 and Na 2 S additive agents worked effective to inhibit elution of Cr. When BFS was used, the elution of Pb, Cd and Cr was inhibited for the all products prepared. In the case of LA-Cement, the elution of Pb and Cd was inhibited for the all products, but only the product that was added FeSO 4 showed good result of the elution of Cr. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.K.; Wall, T.F.; Creelman, R.A.; Gupta, R.P. [University of Newcastle, Newcastle, NSW (Australia). CRC for Black Coal Utilisation

1998-07-01

A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degree}C. The temperature corresponding to the rapid rate of shrinkage correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined using a scanning electron microscope (SEM) to identify the associated chemical and physical changes. The progressive changes in the range of chemical composition (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenisation, viscosity and ash fusion mechanisms. Alternate ash fusion temperatures based on different levels of shrinkage have also been suggested to characterise the ash deposition tendency of the coals. 13 refs., 9 figs.

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

Science.gov (United States)

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

2011-01-01

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

The application of electrocoagulation for the conversion of MSWI fly ash into nonhazardous materials.

Science.gov (United States)

Liao, Wing-Ping; Yang, Renbo; Kuo, Wei-Ting; Huang, Jui-Yuan

2014-05-01

This research investigated the electrocoagulation of municipal solid waste incineration (MSWI) fly ash at a liquid-to-solid ratio (L/S) of 20:1. The leachate that was obtained from this treatment was recovered for reutilization. Two different anodic electrodes were investigated, and two unit runs were conducted. In Unit I, the optimum anode was chosen, and in Unit II, the optimum anode and the recovered leachate were used to replace deionized water for repeating the same electrocoagulation experiments. The results indicate that the aluminum (Al) anode performed better than the iridium oxide (IrO2) anode. The electrocoagulation technique includes washing with water, changing the composition of the fly ash, and stabilizing the heavy metals in the ash. Washing with water can remove the soluble salts from fly ash, and the fly ash can be converted into Friedel's salt (3CaO·Al2O3·CaCl2·10H2O) under an uniform electric field and the sacrificial release of Al(+3) ions, which stabilizes the toxic heavy metals and brings the composition of the fly ash to within the regulatory limits of the toxicity characteristic leaching procedure (TCLP). Use of the Al anode to manage the MSWI fly ash and the leachate obtained from the electrocoagulation treatment is therefore feasible. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pervious concrete using fly ash aggregate as coarse aggregate-an experimental study

Science.gov (United States)

Dash, Subhakanta; Kar, Biswabandita; Mukherjee, Partha Sarathi

2018-05-01

The present study deals with the fabrication of pervious concrete from fly ash aggregates. The pervious concrete were obtained by the mixture of three different size fly ash aggregates (4.75 mm,9.5 mm,12.5 mm), Portland cement, water with little amount of sand or without sand. Admixtures like Silica fume(SF) and Super plasticizer are added to the mixture to enhance the strength of concrete. Trial being taken on preparation of Fly ash based pervious concrete (FPC) with different w/c ratio i.e. 0.30, 0.35 and 0.40 respectively. Tests such as porosity, permeability and compressive, strength are studied for this concrete material and the result concluded that the concrete when cured for 28 days its compressive strength falls in between 7.15 - 15.74 MPa and permeability 9.38 - 16.07 mm/s with porosity 27.59 - 34.05% and these are suited to be used as for use as an environment friendly concrete.

Gravel road stabilisation of Ehnsjoevaegen, Hallstavik[Using fly ash]; Skogsbilvaegsrenovering av Ehnsjoevaegen, Hallstavik

Energy Technology Data Exchange (ETDEWEB)

Macsik, Josef; Svedberg, Bo [Ecoloop, Stockholm (Sweden)

2006-03-15

Fly ash in geotechnical applications has stabilising, isolating, low permeability and hardening effect. Fly ash can be used in road constructions with low bearing capacity, as well as on top cover material on landfills. The aim of the project was to build a road section with fly ash stabilised gravel, based on laboratory studies, and follow up technical and environmental aspect during the first year after stabilisation. The overall aim of this project was to evaluate fly ash from Holmen Paper, Hallstavik, from technical and environmental point of view in a gravel road construction. A gravel road, Ehnsjoevaegen, was stabilised with fly ash during autumn 2004. This road was a low priority road. The fly ash stabilised road section was 1300 m long. Gravel from the road Ehnsjoevaegen was stabilised and investigated in a laboratory study. Leachability of metals and geotechnical aspects were investigated. The laboratory study showed that fly ash stabilised gravel has high shear strength, however its thawing resistance is not fully acceptable. Additives of cement or merit are needed in order to increase its thawing resistance. The actual road section is not going to be used during thawing period and no additives were used. The test road is divided into different sections including a reference section. The road stabilisation work was conducted with gravel transported to Ehnsjoevaegen from off site and not with gravel from the site. Fly ash was tipped off on a levelled road, followed by tipping of gravel. Mixing fly ash and gravel was done on site by a road scraper. After the mixing the road was gravelled with 0,1 m graded gravel. In this project the fly ash had low water content. In order to get optimal compaction water was added from a tanker supplying water before compacted with a compactor. Results from the pilot test shows that fly ash stabilised gravel can be tipped, mixed and compacted effectively. Tipping can be optimised if fly ash and gravel is mixed in a mixer

A feasibility study on oxidation state of arsenic in cut tobacco, mainstream cigarette smoke and cigarette ash by X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Liu, C.; Hu, J.; McAdam, K.G.

2009-01-01

This work describes the application of synchrotron-based X-ray Absorption Near-Edge Structure spectroscopy to study the oxidation state of arsenic in cigarette mainstream smoke, cut tobacco and cigarette ash. The level of arsenic in the total particulate matter of the smoke is approximately 1 ppm for the standard research reference cigarette 2R4F and its replacement 3R4F. Smoke particulate samples collected by a conventional glass-fiber membrane (commercially known as Cambridge filter pad) and a jet-impaction method were analyzed and compared. In addition smoke particulate samples were aged either at ambient temperature or at 195 K. X-ray Absorption Near-Edge Structure spectroscopy results revealed that the cut tobacco powder and cigarette ash contained almost exclusively As V . The smoke particulate samples however contained a mixture of As III and As V . The As V in the smoke particulate was reduced to As III upon aging. Stabilizing the smoke particulate matter at 195 K by solid CO 2 slowed down this aging reaction and revealed a higher percentage of As V . This behavior is consistent with the redox properties of the arsenic species and the smoke particulate matrix.

Magnetic mapping of distribution of wood ash used for fertilization of forest soil

Czech Academy of Sciences Publication Activity Database

Petrovský, Eduard; Remeš, J.; Kapička, Aleš; Podrázský, V.; Grison, Hana; Borůvka, L.

2018-01-01

Roč. 626, June (2018), s. 228-234 ISSN 0048-9697 Institutional support: RVO:67985530 Keywords : forest soil * wood ash * fertilizing * tree plants * iron oxides * rock magnetism Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 4.900, year: 2016

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

Energy Technology Data Exchange (ETDEWEB)

Steenari, Britt-Marie; Noren, Katarina

2008-06-15

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

Wood ash application increases pH but does not harm the soil mesofauna

DEFF Research Database (Denmark)

Qin, Jiayi; Hovmand, Mads Frederik; Ekelund, Flemming

2017-01-01

Application of bioash from biofuel combustion to soil supports nutrient recycling, but may have unwanted and detrimental ecotoxicological side-effects, as the ash is a complex mixture of compounds that could affect soil invertebrates directly or through changes in their food or habitat conditions...... is the likely cause of effects while high pH and heavy metals is of minor importance.......Application of bioash from biofuel combustion to soil supports nutrient recycling, but may have unwanted and detrimental ecotoxicological side-effects, as the ash is a complex mixture of compounds that could affect soil invertebrates directly or through changes in their food or habitat conditions....... To examine this, we performed laboratory toxicity studies of the effects of wood-ash added to an agricultural soil and the organic horizon of a coniferous plantation soil with the detrivore soil collembolans Folsomia candida and Onychiurus yodai, the gamasid predaceous mite Hypoaspis aculeifer...

Preparation of sintered foam materials by alkali-activated coal fly ash.

Science.gov (United States)

Zhao, Yelong; Ye, Junwei; Lu, Xiaobin; Liu, Mangang; Lin, Yuan; Gong, Weitao; Ning, Guiling

2010-02-15

Coal fly ash from coal fired power stations is a potential raw material for the production of ceramic tiles, bricks and blocks. Previous works have demonstrated that coal fly ash consists mainly of glassy spheres that are relatively resistant to reaction. An objective of this research was to investigate the effect of alkali on the preparation process of the foam material. Moreover, the influence of foam dosage on the water absorption, apparent density and compressive strength was evaluated. The experimental results showed that homogenous microstructures of interconnected pores could be obtained by adding 13 wt.% foaming agent at 1050 degrees C, leading to foams presenting water absorption, apparent density and compressive strength values of about 126.5%, 0.414 g/cm(3), 6.76 MPa, respectively.

Aluminothermic reduction of Cr2O3 contained in the ash of thermally treated leather waste

Directory of Open Access Journals (Sweden)

B. M. Wenzel

2013-03-01

Full Text Available In this study the viability of utilising ashes with high chromium oxide content, obtained by thermal treatment of footwear leather waste, in the production of low-carbon ferrochromium alloy (Fe-Cr-LC by aluminothermic reduction was investigated. The following key-factors were selected for process modelling: the quantity of aluminium (Al employed in the reaction, the iron amount added, the iron compound (Fe and/or Fe2O3 used, and the chromic acid addition. The process was investigated using a 2(4 full factorial design where the percentage of Cr2O3 reduced was used as the response. Variance analysis was employed to determine the significant effects and to validate the obtained model. The model was useful for finding the optimal operating conditions, including the maximisation of chromium conversion and the gross margin. Both resulted in similar process conditions, with 76.8±12.3% of chromium being reduced to the metallic phase, and 1.65±0.52 USD (kg ash-1 as the gross margin. The qualities of some alloys obtained were investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy analysis (SEM/EDS. The results showed that the main problem for these alloys in a standard specification was the P and S content, suggesting that a pre-treatment is required.

Survey for tolerance to emerald ash borer within North American ash species

Science.gov (United States)

Jennifer L. Koch; Mary E. Mason; David W. Carey; Kathleen Knight; Therese Poland; Daniel A. Herms

2010-01-01

Since the discovery of the emerald ash borer (EAB) near Detroit, MI, in 2002, more than 40 million ash trees have been killed and another 7.5 billion are at risk in the United States. When the EAB outbreak was initially discovered, our native ash species appeared to have no resistance to the pest.

Cast-concrete products made with FBC ash and wet-collected coal-ash

Energy Technology Data Exchange (ETDEWEB)

Naik, T.R.; Kraus, R.N.; Chun, Y.M.; Botha, F.D. [University of Wisconsin, Milwaukee, WI (United States)

2005-12-01

Cast-concrete hollow blocks, solid blocks, and paving stones were produced at a manufacturing plant by replacing up to 45% (by mass) of portland cement with fluidized bed combustion (FBC) coal ash and up to 9% of natural aggregates with wet-collected, low-lime, coarse coal-ash (WA). Cast-concrete product specimens of all three types exceeded the compressive strength requirements of ASTM from early ages, with the exception of one paving-stone mixture, which fell short of the requirement by less than 10%. The cast-concrete products made by replacing up to 40% of cement with FBC ash were equivalent in strength (89-113% of control) to the products without ash. The abrasion resistance of paving stones was equivalent for up to 34% FBC ash content. Partial replacement of aggregates with WA decreased strength of the products. The resistance of hollow blocks and paving stones to freezing and thawing decreased appreciably with increasing ash contents. The cast-concrete products could be used indoors in regions where freezing and thawing is a concern, and outdoors in a moderate climate.

Geopolymer obtained from coal ash; Geopolimeros obtidos a partir de cinzas de carvao mineral

Energy Technology Data Exchange (ETDEWEB)

Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M., E-mail: amb@unesc.net [Universidade do Extremo Sul Catarinense (UNESC), Criciuma, SC (Brazil). Grupo de Materiais Ceramicos e Vitreos

2011-07-01

Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

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'.

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

Utilization of fly ash as partial sand replacement in oil palm shell lightweight aggregate concrete

Science.gov (United States)

Nazrin Akmal, A. Z. Muhammad; Muthusamy, K.; Mat Yahaya, F.; Hanafi, H. Mohd; Nur Azzimah, Z.

2017-11-01

Realization on the increasing demand for river sand supply in construction sector has inspired the current research to find alternative material to reduce the use of natural sand in oil palm shell lightweight aggregate concrete (OPS LWAC) production. The existence of fly ash, a by-product generated from coal power plant, which pose negative impact to the environment when it is disposed as waste, were used in this research. The effect of fly ash content as partial sand replacement towards workability and compressive strength of OPS lightweight aggregate concrete were investigated. Four concrete mixes containing various percentage of fly ash that are 0%, 10%, 20% and 30% by weight of sand were used in the experimental work. All mixes were cast in form of cubes before subjected to water curing until the testing age. Compressive strength test were conducted at 1, 3, 7 and 28 days. The finding shows that the workability of the OPS LWAC decreases when more fly ash are used as sand replacement. It was found that adding of 10% fly ash as sand replacement content resulted in better compressive strength of OPS LWAC, which is higher than the control mix.

14C age of the ash found in the peat bed of upland dog, Nakagawa-Gun, Hokkaido

International Nuclear Information System (INIS)

Igarashi, Yaeko; Kondo, Tsutomu; Fujiwara, Koichiro.

1983-01-01

The determination of the 14 C age of volcanic ash forming thin layer, which was found in a peat bed, was carried out. The samples were collected from the peat bed which distributes on the flat top of upland about 450m above sea level. The moor spread in the experimental plantation of the agricultural department of Hokkaido University. The thin layer of volcanic ash was found 20 cm deep in the peat bed and with about 1-3 cm thickness. The determination of 14 C age was made on the peat directly beneath the volcanic ash layer, along with the mineralogical studies. The obtained 14 C age was 480 480 +- 100 Y.B.P. (A.D. 1470), and this is presumed to be the age of eruption of the volcanic ash. The color of the ash was greenish yellow or orange in wet state, and grayish white in dry state. The volcanic ash was fine grained pumiceous, and round or nearly round grains predominate. By macroscopic observation, the grains were found to be composed of fibrous volcanic glass. The volcanic ash was well sorted, and the central grain size was 0.11 mm. Heavy liquid method was applied for the determination of heavy minerals. The weight percentage of heavy minerals was 1.59, and the characteristic of this ash was the entire absence of amphibole. Further investigation is necessary for clarifying the distribution of volcanic ash and the source of eruption. (Ishimitsu, A.)

Evaluation of the effects of coal fly ash amendments on the toxicity of a contaminated marine sediment

Energy Technology Data Exchange (ETDEWEB)

Burgess, R.M.; Perron, M.M.; Friedman, C.L.; Suuberg, E.M.; Pennell, K.G.; Cantwell, M.G.; Pelletier, M.C.; Ho, K.T.; Serbst, J.R.; Ryba, S.A. [US EPA, Narragansett, RI (USA). Office for Research and Development

2009-01-15

Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.

Mercury removal from coal combustion flue gas by fly ash

Energy Technology Data Exchange (ETDEWEB)

Kuang, Junyan [Chinese Academy of Sciences, Beijing (China). Research Center for Process Pollution Control; Chinese Academy of Sciences, Beijing (China). Graduate Univ.; Xu, Wenqing; Zhu, Tingyu; Jing, Pengfei [Chinese Academy of Sciences, Beijing (China). Research Center for Process Pollution Control

2013-07-01

The effect of physicochemical properties on the mercury adsorption performance of three fly ash samples has been investigated. The samples were tested for mercury adsorption using a fixed-bed with a simulated gas. X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy and other methods were used to characterize the samples. The results indicate that mercury adsorption on fly ash is mainly physisorption and chemisorption. Uncompleted burned carbon is an important factor for the improvement of mercury removal efficiency, especially, the C-M bond may improve the oxidation of mercury, which formed via the reaction of C and Ti, Si and other elements. The higher specific surface areas and smaller pore diameter are all beneficial for the high mercury removal efficiency. The presence of O{sub 2} plays a positive role on Hg adsorption of modified fly ash, while SO{sub 2} has double role of inhibition because of competitive adsorption and promotion to chemisorption. In addition, sample modified with FeCl{sub 3} has a great performance in Hg removal.

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)

Lunar ash flows - Isothermal approximation.

Science.gov (United States)

Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

1972-01-01

Suggestion of the ash flow mechanism as one of the major processes required to account for some features of lunar soil. First the observational background and the gardening hypothesis are reviewed, and the shortcomings of the gardening hypothesis are shown. Then a general description of the lunar ash flow is given, and a simple mathematical model of the isothermal lunar ash flow is worked out with numerical examples to show the differences between the lunar and the terrestrial ash flow. The important parameters of the ash flow process are isolated and analyzed. It appears that the lunar surface layer in the maria is not a residual mantle rock (regolith) but a series of ash flows due, at least in part, to great meteorite impacts. The possibility of a volcanic contribution is not excluded. Some further analytic research on lunar ash flows is recommended.

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

International Nuclear Information System (INIS)

Biganzoli, Laura; Gorla, Leopoldo; Nessi, Simone; Grosso, Mario

2012-01-01

Highlights: ► Aluminium packaging partitioning in MSW incineration residues is evaluated. ► The amount of aluminium packaging recoverable from the bottom ashes is evaluated. ► Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. ► 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-03-15

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

A Study of the Stability and Characterization Plutonium Dioxide and Chemical Characterization [of] Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash

International Nuclear Information System (INIS)

Ray, A.K.; Boettger, J.C.; Behrens, Robert G.

1999-01-01

In the presentation ''A Study of the Stability and Characterization of Plutonium Dioxide'', the authors discuss their recent work on actinide stabilities and characterization, in particular, plutonium dioxide PuO 2 . Earlier studies have indicated that PuO 2 has the fluorite structure of CaF 2 and typical oxide semiconductor properties. However, detailed results on the bulk electronic structure of this important actinide oxide have not been available. The authors have used all-electron, full potential linear combinations Gaussian type orbitals fitting function (LCGTO-FF) method to study PuO 2 . The LCGTO-FF technique characterized by its use of three independent GTO basis sets to expand the orbitals, charge density, and exchange-correlation integral kernels. Results will be presented on zero pressure using both the Hedin-Lundquist local density approximation (LDA) model or the Perdew-Wang generalized gradient approximation (GGA) model. Possibilities of different characterizations of PuO 2 will be explored. The paper ''Chemical Characterization Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash'' describes the results of a comprehensive study of the chemical characteristics of virgin, calcined and fluorinated incinerator ash produced at the Rocky Flats Plant and at the Los Alamos National Laboratory prior to 1988. The Rocky Flats and Los Alamos virgin, calcined, and fluorinated ashes were also dissolved using standard nitrate dissolution chemistry. Corresponding chemical evaluations were preformed on the resultant ash heel and the results compared with those of the virgin ash. Fluorination studies using FT spectroscopy as a diagnostic tool were also performed to evaluate the chemistry of phosphorus, sulfur, carbon, and silicon containing species in the ash. The distribution of plutonium and other chemical elements with the virgin ash, ash heel, fluorinated ash, and fluorinated ash heel particulates were studied in detail using microprobe analysis. Some

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

DEFF Research Database (Denmark)

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

2003-01-01

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

Ashes from biofuels and mixed fuels - amount and qualities

International Nuclear Information System (INIS)

Bjurstroem, Henrik; Ilskog, Elisabeth; Berg, Magnus

2003-04-01

In this study, ashes from biofuels used in the energy utilities, the pulp and paper industry and the wood-working industries have been inventoried. The selection of plants to which enquiries were addressed consists of about 50 utilities, all pulp and paper plants and about 20 wood-working industries (e.g. sawmills). The purpose of the study was to estimate the quantities of bio ashes that are recycled to the forests and those that could be recycled. The background to this study is that logging slash is harvested from ca 30,000 ha per year, while ash is recycled only to 2 to 4,000 ha per year. A working hypothesis has been that logging slash or clean wooden fuels are mixed with other fuels to such an extent that the ash is too contaminated to be recycled. The consequence would be that there is a shortage of suitable ash. Therefore, it was desirable that motives for mixing fuels be chartered. In Sweden, approximately one million ton ashes are produced each year and the share of the three industries that have been studied is estimated as: 200 - 340,000 tons from utilities about 275,000 tons from the pulp and paper industry and 100,000 tons from the woodworking industry. These quantities include unburned carbon, water added when the ash is extracted from the boilers etc. Additional quantities of ash are those produced by waste combustion (447,000 tons), wood-burning in residential buildings (50 - 100,000 tons) etc. In all, ash that may be recycled should total about 300,000 tons (Recyclable ash in t/a: Utilities - 80,000; Pulp and Paper Industry - 100-130,000; Woodworking Industry 100,000). Logging slash is seldom burned alone in the boilers at the utilities, but are almost always mixed with other wood fuel fractions such as waste from sawmills. The mixtures can be very complex. Clean mixtures of wood fuel fractions represent ca 4,500 GWh of the ca 7,800 GWh in this study. Other fuels that are often used in mixtures are peat and Salix, which does not necessarily lead

The use of fly-ash particles for dating lake sediments

Energy Technology Data Exchange (ETDEWEB)

Rose, N L [Environmental Change Research Centre, University College London, London (United Kingdom)

1998-08-01

Fly-ash particles comprise two particle types, spheroidal carbonaceous particles (SCP) and inorganic ash spheres (IAS). In lake sediments, these particles form an unambiguous record of atmospheric deposition of industrial pollutants. The main temporal trends of these sediment records have been found to be remarkably consistent over wide geographical areas and these features can be used to ascribe dates to cores undated by other means. SCP are the main particle type used in this way as they are easier to extract and enumerate. IAS are morphologically similar to some natural particles (volcanic, meteoritic) and therefore show a natural background concentration at all pre-industrial sediment depths. Apart from this background temporal trends are similar to SCP and IAS could be used for dating in the same way. Gaining an indication of fuel-type change, either from IAS:SCP ratio or chemical characterization of SCP enables additional dates to be added to sediment cores through comparison with documentary evidence. In the future, as {sup 210}Pb becomes progressively unable to date the post-industrial sediment record, dating using fly-ash techniques may become increasingly important. (orig.) 17 refs.

The use of fly-ash particles for dating lake sediments

International Nuclear Information System (INIS)

Rose, N.L.

1998-01-01

Fly-ash particles comprise two particle types, spheroidal carbonaceous particles (SCP) and inorganic ash spheres (IAS). In lake sediments, these particles form an unambiguous record of atmospheric deposition of industrial pollutants. The main temporal trends of these sediment records have been found to be remarkably consistent over wide geographical areas and these features can be used to ascribe dates to cores undated by other means. SCP are the main particle type used in this way as they are easier to extract and enumerate. IAS are morphologically similar to some natural particles (volcanic, meteoritic) and therefore show a natural background concentration at all pre-industrial sediment depths. Apart from this background temporal trends are similar to SCP and IAS could be used for dating in the same way. Gaining an indication of fuel-type change, either from IAS:SCP ratio or chemical characterization of SCP enables additional dates to be added to sediment cores through comparison with documentary evidence. In the future, as 210 Pb becomes progressively unable to date the post-industrial sediment record, dating using fly-ash techniques may become increasingly important. (orig.)

Post-treatment of Fly Ash by Ozone in a Fixed Bed Reactor

DEFF Research Database (Denmark)

Pedersen, Kim Hougaard; Melia, M. C.; Jensen, Anker Degn

2009-01-01

to be fast. A kinetic model has been formulated, describing the passivation of carbon, and it includes the stoichiometry of the ozone consumption (0.8 mol of O-3/kg of C) and an ineffective ozone loss caused by catalytic decomposition. The simulated results correlated well with the experimental data....... prevents the AEA to be adsorbed. In the present work, two fly ashes have been ozonated in a fixed bed reactor and the results showed that ozonation is a potential post-treatment method that can lower the AEA requirements of a fly ash up to 6 times. The kinetics of the carbon oxidation by ozone was found...

Environmental effects of ash recycling on the incidence of 137Cs in vegetation and soil. Final report

International Nuclear Information System (INIS)

Hoegbom, Lars; Nohrstedt, Hans-Oerjan

2000-08-01

Recycling of wood-ash from combustion of bio-fuel could in the future become a common practice in Swedish forestry. As a consequence of the Chernobyl radioactive fallout in 1986 large areas in central Sweden became contaminated. There is a risk that addition of wood-ash originating from these contaminated areas will increase the activity of 137 Cs in a forests if added to a non-contaminated area. We report here of measurements of 137 Cs activity in different coniferous forest compartments from seven field experiments. The activity measurements were made 5-8 years after wood-ash application. The field experiments, in a north-south transect in Sweden, have received a background activity ranging 0 - 40 kBq m -2 as a consequence of the Chernobyl fallout. The applied wood-ash had an activity ranging between 0 - 4.8 kBq kg -1 depending on origin. Samples of the various compartments, taken in autumn 1999, included samples of soil, field vegetation, needles and wood (both twigs and stem wood). The soil and the field-vegetation were analysed using a NaI detector while the samples obtained from the trees were analysed on a GeLi detector. In addition, the soil samples were also analysed for K, by extraction with 1M ammonium lactate. The highest 137 Cs activity concentration was, by far, found in the soil, the activity found in the field-layer and the trees was in general lower. At six of seven sites there were no statistically significant effects of the wood-ash application on radiation, despite the fact that the wood-ash had, at least theoretically, in one case doubled the activity. However, at one site (Vindeln), with an intermediate 137 Cs deposition (10-20 kBq m -2 ) from Chernobyl, there was a statistically significant decrease in 137 Cs activity in the soil as well as in needles and twigs at the wood-ash amended plots. This occurred despite that the wood-ash had added a considerable activity (0.63 kBq m -2 ) to the site. The same ash applied to another site also

Direct Quantitative Analysis of Arsenic in Coal Fly Ash

Directory of Open Access Journals (Sweden)

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%.

Sewage sludge ash — A promising secondary phosphorus source for fertilizer production

Energy Technology Data Exchange (ETDEWEB)

Herzel, Hannes, E-mail: hannes.herzel@bam.de [BAM Federal Institute for Materials Research and Testing Richard-Willstätter-Straße 11, 12489 Berlin (Germany); Krüger, Oliver [BAM Federal Institute of Materials Research and Testing, Unter den Eichen 87, 12205 Berlin (Germany); Hermann, Ludwig [Outotec GmbH & Co KG, Ludwig-Erhard-Straße 21, 61440 Oberursel (Germany); Adam, Christian [BAM Federal Institute of Materials Research and Testing, Unter den Eichen 87, 12205 Berlin (Germany)

2016-01-15

Sewage sludge incineration is extensively practiced in some European countries such as the Netherlands, Switzerland, Austria and Germany. A survey of German sewage sludge ash showed that the recovery potential is high, approx. 19,000 t of phosphorus per year. However, the survey also discovered that the bioavailability of phosphorus in the sewage sludge ash is poor and that more than half of the ashes cannot be used as fertilizers due to high heavy metal content. A new thermochemical process for sewage sludge ash treatment was developed that transforms the ash into marketable fertilizer products. Sewage sludge ash was thermochemically treated with sodium and potassium additives under reducing conditions, whereby the phosphate-bearing mineral phases were transformed into plant available phosphates. High P-bioavailability was achieved with a molar Na/P ratio > 1.75 in the starting materials. Sodium sulfate, carbonate and hydroxide performed comparably as additives for this calcination process. Potassium carbonate and -hydroxide have to be added in a molar K/P ratio > 2.5 to achieve comparable P-solubility. The findings of the laboratory scale investigations were confirmed by an industrial demonstration trial for an ash treatment with sodium sulfate. Simultaneously, the volatile transition metal arsenic (61% removal) as well as volatile heavy metals such as cadmium (80%), mercury (68%), lead (39%) and zinc (9%) were removed via the off-gas treatment system. The product of the demonstration trial is characterized by high bioavailability and a toxic trace element mass fraction below the limit values of the German fertilizer ordinance, thus fulfilling the quality parameters for a P-fertilizer. - Highlights: • Direct use of sewage sludge ashes (SSA) as fertilizer often not possible • New approach of SSA treatment aiming at P-fertilizers with high P-bioavailability • Comparison of different Na- and K-bearing additives for the thermochemical process • Evaporation of

Sewage sludge ash — A promising secondary phosphorus source for fertilizer production

International Nuclear Information System (INIS)

Herzel, Hannes; Krüger, Oliver; Hermann, Ludwig; Adam, Christian

2016-01-01

Sewage sludge incineration is extensively practiced in some European countries such as the Netherlands, Switzerland, Austria and Germany. A survey of German sewage sludge ash showed that the recovery potential is high, approx. 19,000 t of phosphorus per year. However, the survey also discovered that the bioavailability of phosphorus in the sewage sludge ash is poor and that more than half of the ashes cannot be used as fertilizers due to high heavy metal content. A new thermochemical process for sewage sludge ash treatment was developed that transforms the ash into marketable fertilizer products. Sewage sludge ash was thermochemically treated with sodium and potassium additives under reducing conditions, whereby the phosphate-bearing mineral phases were transformed into plant available phosphates. High P-bioavailability was achieved with a molar Na/P ratio > 1.75 in the starting materials. Sodium sulfate, carbonate and hydroxide performed comparably as additives for this calcination process. Potassium carbonate and -hydroxide have to be added in a molar K/P ratio > 2.5 to achieve comparable P-solubility. The findings of the laboratory scale investigations were confirmed by an industrial demonstration trial for an ash treatment with sodium sulfate. Simultaneously, the volatile transition metal arsenic (61% removal) as well as volatile heavy metals such as cadmium (80%), mercury (68%), lead (39%) and zinc (9%) were removed via the off-gas treatment system. The product of the demonstration trial is characterized by high bioavailability and a toxic trace element mass fraction below the limit values of the German fertilizer ordinance, thus fulfilling the quality parameters for a P-fertilizer. - Highlights: • Direct use of sewage sludge ashes (SSA) as fertilizer often not possible • New approach of SSA treatment aiming at P-fertilizers with high P-bioavailability • Comparison of different Na- and K-bearing additives for the thermochemical process • Evaporation of

Use of coal ash in production of concrete containing contaminated sand

International Nuclear Information System (INIS)

Ezeldin, A.S.

1991-01-01

There are between 2 to 3.5 million underground storage tanks located throughout the nation. Most of these tanks, which store oils and gasolines, are leaking making them one of the primary sources of soil contamination. Adding coal ash or cement to contaminated soil has been used to obtain stationary and inert wastecrete. By using this procedure, stabilization (limiting the solubility and mobility of the contaminants) and solidification (producing a solid waste block) of contaminated soils are successfully achieved. This paper investigates another re-use option of coal ash and contaminated soils. An experimental study evaluating the effectiveness of using coal ash with oil contaminated sand in concrete production is presented. A control mix made of clean sand was designed to yield 500 psi of compressive strength. Sand, artificially contaminated with 3% by weight of motor oil, was used as clean sand replacement. Six concrete mixtures were tested in compression and flexure. The six mixtures were obtained by increasing the ratio of contaminated sand to clean sand, namely; 10%, 20% and 40% and by introducing coal ash to the concrete mixture, namely; 20% of the cement weight. The test results indicate that the inclusion of oil contaminated sand in concrete reduces the compressive and flexural strengths. However, this decrease in strength is compensated by introducing coal ash in the mixture. Regaining that strength offers the possibility of using such concrete as a construction material in special structural applications. More research is required to establish better understanding of that composite and suggest feasible applications

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.

First international ash marketing and technology conference

Energy Technology Data Exchange (ETDEWEB)

1978-01-01

A total of 42 papers were presented in sessions with the following headings: production and disposal of ash - an international review; environmental, health, safety, and legal aspects of ash handling; marketing of ash; development of new uses for ash; cementitious use of ash; ash in manufactured products; and geotechnical uses of ash.

Studies on the Effect of Rice Husk Ash as Cement Admixture * M.U ...

African Journals Online (AJOL)

acer

Studies on the Effect of Rice Husk Ash as Cement Admixture. *. 1. M.U Dabai,. 1 ... production of durable concrete and at the same time it is a ... indigenous and waste, materials in concrete. One .... (4.08%). The Iron oxide may be from laterite.

Sulfidation treatment of molten incineration fly ashes with Na2S for zinc, lead and copper resource recovery.

Science.gov (United States)

Kuchar, D; Fukuta, T; Onyango, M S; Matsuda, H

2007-04-01

The present study focuses on the conversion of heavy metals involved in molten incineration fly ashes to metal sulfides which could be thereafter separated by flotation. The sulfidation treatment was carried out for five molten incineration fly ashes (Fly ash-A to Fly ash-E) by contacting each fly ash with Na(2)S solution for a period of 10 min to 6h. The initial molar ratio of S(2-) to Me(2+) was adjusted to 1.20. The conversion of heavy metals to metal sulfides was evaluated by measuring the S(2-) residual concentrations using an ion selective electrode. The formation of metal sulfides was studied by XRD and SEM-EDS analyses. In the case of Fly ash-A to Fly ash-D, more than 79% of heavy metals of zinc, lead and copper was converted to metal sulfides within the contacting period of 0.5h owing to a fast conversion of metal chlorides to metal sulfides. By contrast, the conversion of about 35% was achieved for Fly ash-E within the same contacting period, which was attributed to a high content of metal oxides. Further, the S(2-) to Me(2+) molar ratio was reduced to 1.00 to minimize Na(2)S consumption and the conversions obtained within the contacting period of 0.5h varied from 76% for Fly ash-D to 91% for Fly ash-C. Finally, soluble salts such as NaCl and KCl were removed during the sulfidation treatment, which brought about a significant enrichment in metals content by a factor varying from 1.5 for Fly ash-D to 4.9 for Fly ash-A.

Determining ash content in flotation wastes by means of the MPOF optical ash meter. [Poland

Energy Technology Data Exchange (ETDEWEB)

Sikora, T; Sliwa, J

1982-03-01

The paper evaluates an experimental unit of the MPOF optical ash meter, developed by the EMAG Research and Production Center for Electrical Engineering and Mining Automation. The MPOF, which is being tested at the coal preparation plant of the 30 lecia PRL mine, is the first system for continuous determination of ash content in flotation tailings developed in Poland. A block scheme of the system is given. It consists of a measuring head and electronic system which processes data supplied by the measuring head and calculates ash content. System operation is based on the principle of determining ash content in a mixture of coal and mineral wastes by measuring mixture reflectivity. Determining ash content in the mixture is possible as reflectivity coefficients for coal and ash are constant. Performance of the MPOF optical ash meter is evaluated; the results are shown in a table and a scheme. Measurement accuracy is satisfactory.

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

International Nuclear Information System (INIS)

Kalb, P.D.; Heiser, J.H. III; Colombo, P.

1990-01-01

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

Formation of Plant Sterol Oxidation Products in Foods during Baking and Cooking Using Margarine without and with Added Plant Sterol Esters

NARCIS (Netherlands)

Lin, Y.; Knol, D.; Menéndez-Carreño, M.; Blom, W.A.M.; Matthee, J.; Janssen, H.G.; Trautwein, E.A.

2016-01-01

Plant sterols (PS) in foods are subject to thermal oxidation to form PS oxidation products (POP). This study measured POP contents of 19 foods prepared by typical household baking and cooking methods using margarines without (control) and with 7.5% added PS (as 12.5% PS-esters, PS-margarine). Median

Radon exhalation study from cement, cement slabs and concrete slabs with variation in fly ash

International Nuclear Information System (INIS)

Sharma, Nisha; Singh, Jaspal

2012-01-01

Fly ash is a waste product from coal-fired power plants. Fly ash has become a subject of world-wide interest in recent years because of its diverse uses, e.g. in the manufacture of concrete for building purposes, for the filling of underground cavities, or as a component of building material. The fly ash may contain enhanced levels of the natural radionuclides in the uranium and thorium series and by using the fly ash in building materials, the radiation levels in houses may thus be technologically enhanced. Because of its relatively high radionuclide contents (including 226 Ra), fly ash may, however, present a potential hazard to the population through its radon emanation, which would be highly undesirable. Since fly ash is frequently used as a building material, the idea of the experiment was to mix fly ash in different proportions in the cement in the powder form, cemented slabs and concrete slabs to study the combined behaviors. Alpha sensitive LR-115 type II plastic track detector, commonly known as Solid State Nuclear Track Detectors (SSNTDs), were used to measure the radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon concentrations were determined. In case of cement in the powder form and in cemented slab, starting from the pure cement, fly ash was added up to 70% by weight. In this case the radon exhalation rate has increased by addition of fly ash in the cement and in case of concrete slabs by the addition of fly ash in the cement the radon exhalation increases up to 60% and then decreases. Therefore, on the basis of our investigations we concluded that in general radon exhalation rate increases with the addition of fly ash. (author)

Mechanical behavior of cementitious composites with processed sugar cane bagasse ashes

International Nuclear Information System (INIS)

Bezerra, Augusto C.S.; Saraiva, Sergio L.C.; Sena, Natalia O.; Pereira, Gabriela M.; Rodrigues, Conrado S.; Ferreira, Maria C.N.F.; Castro, Laurenn W.A.; Silva, Marcos V.M.S.; Gomes, Romero C.; Aguilar, Maria T.P.

2014-01-01

Sugar cane bagasse is waste from the sugar and ethanol industry and is primarily intended for burning in boilers to generate energy. As waste from the cogeneration of energy, sugar cane bagasse ashes (SCBA) are produced with no honorable destination. This paper studies the use of SCBA to partially replace Portland cement in producing cementitious composites. The ashes were processed by reburning and grinding, and after processing were characterized by a scanning electron microscope, x-ray diffraction, laser granulometry, and x-ray fluorescence spectrometry. After characterization, cement compounds were fashioned, replacing 0, 10, 20 and 30% of the cement with SCBA. The composites were mechanically evaluated by means of compression strength tests, tensile strength tests by bending. The results proved significant, indicating the possible use of SCBA when added to the cement on manufacture. (author)

Effect of Ash on Oxygen Carriers for the Application of Chemical Looping Combustion to a High Carbon Char Effet des cendres sur l’activité des porteurs d’oxygène dans la combustion du charbon en boucle chimique

Directory of Open Access Journals (Sweden)

Rubel A.

2011-02-01

Full Text Available The application of Chemical Looping Combustion (CLC to solid fuels is being investigated at the University of Kentucky, Center for Applied Energy Research (CAER with the aim of the development of a Pressurized Chemical Looping Combustion/Gasification (PCLC/G process for the generation of electricity from coal. One important aspect of the CLC of solid fuel is the understanding of the effect of ash on the reactivity of Oxygen Carriers (OCs. The effect of ash on the redox capabilities of two different iron oxide OCs and on their ability to oxidize coal char was studied. To determine the effect of ash on the reactivity and recycle of the OCs through multiple redox cycles, fly ash from a coal-fired power plant was used. These experiments were performed in a TGMS system using 500 mg of ash/OC mixtures containing different ash concentrations up to 75%. The reducing gas was composed of 10% H2, 15% CO, 20% CO2, and a balance of Ar and the oxidizing gas was 20% O2 in Ar. Oxidation/reductions were carried to near completion. The ash was found to contain OC activity related to inherent iron present in the ash confirmed by XRD. This resulted in increased weight gain/loss on oxidation/reduction. The rate of oxidation/reduction increased with ash concentration due to increased porosity of the OC/ash mixture and better access of the reactive gases to the OC target sites. The two OCs were then used to combust a beneficiated coal char in the TGMS with the only oxygen supplied by an iron oxide OC. The starting mixture was 10% char and 90% of one of two OCs studied. The spent material containing reduced OC and ash was re-oxidized and 10% more char was added for a second reduction of the OC and oxidation of the added char. This procedure was repeated for 5 cycles increasing the ash concentrations from 5 to 25% in the char/ash/OC mixture. Carbon removal was 92 to 97.8 and 97.3 to 99.7% for the two different iron oxide OCs tested. Ash was not detrimental to the

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....

Improving the performance of fluorine-doped tin oxide by adding salt

Energy Technology Data Exchange (ETDEWEB)

Purwanto, Agus, E-mail: Aguspur@uns.ac.id [Department of Chemical Engineering, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia); Widiyandari, Hendri [Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Dr. Soedarto, Tembalang, Semarang 50275 (Indonesia); Suryana, Risa [Department of Physics, Faculty of Mathematics and Natural Sciences, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia); Jumari, Arif [Department of Chemical Engineering, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia)

2015-07-01

High-performance fluorine-doped tin oxide (FTO) films were fabricated via a spray deposition technique with salt added to the precursor. The addition of NaCl in the precursor improved the conductivity of the FTO films. Increasing the NaCl concentration to its optimal concentration reduced the sheet resistance of the FTO film. The optimal values for the addition of a NaCl were 0.5, 0.5, 1.5, and 1.5 at.% for the FTO film prepared using NH{sub 4}F concentration of 4, 10, 16, and 22 at.%, respectively. The lowest sheet resistance of the salt-added FTO film was 4.8 Ω/□. The FTO film averaged a transmittance of more than 80% in the visible range region (λ = 400–800 nm). XRD diffractograms confirmed that the crystal structure of the as-grown FTO film was that of a tetragonal SnO{sub 2} and that the addition of salt improved its crystallinity. This film has the potential for use as an electrode for dye-sensitized solar cells (DSSCs). - Highlights: • A method to improve FTO performance using the addition of salt • The FTO film exhibited high performance of conductivity and light transmittance. • This technique is low-cost, fast and scales-up easily using simple devices.

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

Science.gov (United States)

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

2012-04-01

In recent years, several biomass power plants have been installed in Southeastern Spain to reuse olive oil industry residues. This energy production tries to reduce the high costs associated with fossil fuels, but without entering into direct competition to traditional food crops. The waste management in these biomass energy plants is still an issue since there are non-flammable materials which remains after incineration in the form of ashes. In Southeastern Spain there is also a great amount of clayey and marly soils whose volume is very sensitive to changes in climate conditions, making them unsuitable for civil engineering. We propose the use of biomass ash (both fly ash and bottom ash) as a stabilization agent for expansive soils in order to improve the efficiency of construction processes by using locally available materials. In this work biomass ashes from a biomass power plant in Southeastern Spain have been used to stabilize 6 samples of local marly soil. Those 6 samples of expansive soil were mixed with different dosages of biomass ash (2%, 4% and 7%) to create 18 specimens of treated soil, which were submitted to Proctor, Atterberg Limits, pH and Free Swell Index tests, following Spanish Standards UNE by AENOR. X-Ray Diffraction (XRD) tests by powder method were also carried out, using a diffractometer Philips X'Pert-MPD. The results obtained for the original untreated marly soil were: PI = 34.6; Free Swell = 12.5; pH = 8. By adding biomass ash the value of the plasticity index (PI) became slightly lower although it was not low enough as to obtain a non-plastic soil (PI under 25). However, there were dramatical decreases of free swell index (FSI) after the stabilization treatment: FSI < 8.18 (2% biomass); FSI < 6.15 (4% biomass); FSI < 4.18 (7% biomass); These results suggest that treated soil is quite less susceptible than the original soil to moisture changes. The pH of the mixes after adding biomass ash rose from 8 to 11±1 leading to an alkaline

Adding Cellulosic Ash to Composting Mix as a Soil Amendment

Directory of Open Access Journals (Sweden)

Jathwa Abd Alkareem Ibrahim

2016-04-01

Full Text Available Solid waste generation and composition in Baghdad is typically affected by population growth, urbanization, improved economic conditions, changes in lifestyles and social and cultural habits. A burning chamber was installed to burn cellulosic waste only. It was found that combustion reduced the original volume and weight of cellulosic waste by 97.4% and 85% respectively. A batch composting study was performed to evaluate the feasibility of co-composting organic food waste with the cellulosic bottom ash in three different weight ratios (w/w [95/5, 75/25, 50/50]. The composters were kept in controlled aerobic conditions for 7 days. Temperature, moisture, and pH were measured hourly as process successful indicators. Maximum temperature ranged between (41 to 53 ºC. Results showed that the blend of M2 [OFMSW: BCA] [75:25] was the most beneficial to composting. It maintained the highest temperature for the longest duration for 9hrs. at (53 ºC, achieved the highest nitrogen content(1.65% , a C/N ratio of (14.18 %, nitrification index(N-NH4/N-NO3 of (0.29,nitrogen, phosphorous and potassium(NPK(1.65, 1.22, 1.73% respectively, seed germination 80% indicating that the achieved compost is mature and stable. Heavy metal contents (Cd, Cr, Cu, Mn, Ni, Pb and Zn were detected in the above compost and all were lower than the regulation limits of the metal quality standards for compost and stabilized bio-waste.

[Effects of Chinese prickly ash orchard on soil organic carbon mineralization and labile organic carbon in karst rocky desertification region of Guizhou province].

Science.gov (United States)

Zhang, Wen-Juan; Liao, Hong-Kai; Long, Jian; Li, Juan; Liu, Ling-Fei

2015-03-01

Taking 5-year-old Chinese prickly ash orchard (PO-5), 17-year-old Chinese prickly ash orchard (PO- 17), 30-year-old Chinese prickly ash orchard (PO-30) and the forest land (FL, about 60 years) in typical demonstration area of desertification control test in southwestern Guizhou as our research objects, the aim of this study using a batch incubation experiment was to research the mineralization characteristics of soil organic carbon and changes of the labile soil organic carbon contents at different depths (0-15 cm, 15-30 cm, and 30-50 cm). The results showed that: the cumulative mineralization amounts of soil organic carbon were in the order of 30-year-old Chinese prickly ash orchard, the forest land, 5-year-old Chinese prickly ash orchard and 17-year-old Chinese prickly ash orchard at corresponding depth. Distribution ratios of CO2-C cumulative mineralization amount to SOC contents were higher in Chinese prickly ash orchards than in forest land at each depth. Cultivation of Chinese prickly ash in long-term enhanced the mineralization of soil organic carbon, and decreased the stability of soil organic carbon. Readily oxidized carbon and particulate organic carbon in forest land soils were significantly more than those in Chinese prickly ash orchards at each depth (P < 0.05). With the increasing times of cultivation of Chinese prickly ash, the contents of readily oxidized carbon and particulate organic carbon first increased and then declined at 0-15 cm and 15-30 cm depth, respectively, but an opposite trend was found at 30-50 cm depth. At 0-15 cm and 15-30 cm, cultivation of Chinese prickly ash could be good for improving the contents of labile soil organic carbon in short term, but it was not conducive in long-term. In this study, we found that cultivation of Chinese prickly ash was beneficial for the accumulation of labile organic carbon at the 30-50 cm depth.

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

Science.gov (United States)

Chen, Yigen; Poland, Therese M

2009-12-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

Energy Technology Data Exchange (ETDEWEB)

Biganzoli, Laura, E-mail: laura.biganzoli@mail.polimi.it [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy); Gorla, Leopoldo; Nessi, Simone; Grosso, Mario [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Aluminium packaging partitioning in MSW incineration residues is evaluated. Black-Right-Pointing-Pointer The amount of aluminium packaging recoverable from the bottom ashes is evaluated. Black-Right-Pointing-Pointer Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. Black-Right-Pointing-Pointer 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

10 Risk to Ash from Emerald Ash Borer: Can Biological Control Prevent the Loss of Ash Stands

Science.gov (United States)

Ash trees were once relatively free of serious, major diseases and insect pests in North America until the arrival of EAB, which was first detected in North America in Michigan in 2002. As of February 2014, EAB had been detected in 22 U.S. states and two Canadian provinces, killing millions of ash ...

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

OpenAIRE

Antoni; Sulistio Aldi Vincent; Wahjudi Samuel; Hardjito Djwantoro; Hardjito Djwantoro

2017-01-01

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 includi...

Environmental and anthropogenic factors affecting the respiratory toxicity of volcanic ash in vitro

Science.gov (United States)

Tomašek, Ines; Horwell, Claire J.; Damby, David E.; Ayris, Paul M.; Barošová, Hana; Geers, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Clift, Martin J. D.

2016-04-01

Human exposure to inhalable volcanic ash particles following an eruption is a health concern, as respirable-sized particles can potentially contribute towards adverse respiratory health effects, such as the onset or exacerbation of respiratory and cardiovascular diseases. Although there is substantial information on the mineralogical properties of volcanic ash that may influence its biological reactivity, knowledge as to how external factors, such as air pollution, contribute to and augment the potential reactivity is limited. To determine the respiratory effects of volcanic particle interactions with anthropogenic pollution and volcanic gases we will experimentally assess: (i) physicochemical characteristics of volcanic ash relevant to respiratory toxicity; (ii) the effects of simultaneously inhaling anthropogenic pollution (i.e. diesel exhaust particles (DEP)) and volcanic ash (of different origins); (iii) alteration of volcanic ash toxicity following interaction with volcanic gases. In order to gain a first understanding of the biological impact of the respirable fraction of volcanic ash when inhaled with DEP in vitro, we used a sophisticated 3D triple cell co-culture model of the human alveolar epithelial tissue barrier. The multi-cellular system was exposed to DEP [0.02 mg/mL] and then exposed to either a single or repeated dose of well-characterised respirable volcanic ash (0.26 ± 0.09 or 0.89 ± 0.29 μg/cm2, respectively) from the Soufrière Hills volcano, Montserrat for a period of 24 hours using a pseudo-air liquid interface approach. Cultures were subsequently assessed for adverse biological endpoints including cytotoxicity, oxidative stress and (pro)-inflammatory responses. Results indicated that the combination of DEP and respirable volcanic ash at sub-lethal concentrations incited a significant release of pro-inflammatory markers that was greater than the response for either DEP or volcanic ash, independently. Further work is planned, to determine if

Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

KAUST Repository

Andersen, Myrrha E.

2016-10-19

Pulverized bituminous coal was burned in a 10. W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28, 32, and 36%). Experiments were designed to produce flames with practically relevant stoichiometric ratios (SR. =1.2-1.4) and constant residence times (2.3. s). Size-classified fly ash samples were collected, and measurements focused on the soot, elemental carbon (EC), and organic carbon (OC) composition of the total and ultrafine (<0.6. μm) fly ash. Results indicate that although the total fly ash carbon, as measured by loss on ignition, was always acceptably low (<2%) with all three oxy-combustion conditions lower than air-combustion, the ultrafine fly ash for both air-fired and oxy-fired combustion conditions consists primarily of carbonaceous material (50-95%). Carbonaceous components on particles <0.6. μm measured by a thermal optical method showed that large fractions (52-93%) consisted of OC rather than EC, as expected. This observation was supported by thermogravimetric analysis indicating that for the air, 28% oxy, and 32% oxy conditions, 14-71% of this material may be OC volatilizing between 100. C and 550. C with the remaining 29-86% being EC/soot. However, for the 36% oxy condition, OC may comprise over 90% of the ultrafine carbon with a much smaller EC/soot contribution. These data were interpreted by considering the effects of oxy-combustion on flame attachment, ignition delay, and soot oxidation of a bituminous coal, and the effects of these processes on OC and EC emissions. Flame aerodynamics and inlet oxidant composition may influence emissions of organic hazardous air pollutants (HAPs) from a bituminous coal. During oxy-coal combustion, judicious control of inlet oxygen concentration and placement may be used to minimize organic HAP and soot emissions.

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

Unburnt carbon from coal fly ashes as a precursor of activated carbon for nitric oxide removal.

Science.gov (United States)

Rubio, Begoña; Izquierdo, M Teresa; Mayoral, M Carmen; Bona, M Teresa; Andres, Jose M

2007-05-08

The aim of this work is to evaluate the characteristics of an activated carbon obtained from unburnt carbon in coal fly ashes to be used in the removal of NO. Carbon-rich fraction was obtained by mechanical sieving of fly ashes. The mineral matter was removed by conventional HCl and HF demineralization procedure. Activation was carried out with steam at 900 degrees C in order to develop porosity onto the sample. Characterization of samples was performed by several techniques with a main objective: to follow the mineral matter content, composition and distribution on the samples in order to better understand how to remove it from unburnt carbon in fly ashes. To study the use of this unburnt carbon as a precursor for the preparation of activated carbons for gas cleaning, the NO removal by ammonia using activated carbon as a catalyst at low temperature was performed. Results show a good performance of activated carbon in this reaction that is in relationship with BET surface area.

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.

Radioisotope conveyor ash meter

International Nuclear Information System (INIS)

Savelov, V.D.

1994-01-01

Radioisotope conveyor ash meter realizes persistent measuring of ashiness of coal and products of its enrichment on the belt conveyor without contact. The principle of ash meter acting is based on functional dependence of the gamma radiation flows backscattering intensity of radioisotope sources from the ash volume content in the controlled fuel. Facility consists from the ashiness transducer and the processing and control device

Volcanic ash in ancient Maya ceramics of the limestone lowlands: implications for prehistoric volcanic activity in the Guatemala highlands

Science.gov (United States)

Ford, Anabel; Rose, William I.

1995-07-01

In the spirit of collaborative research, Glicken and Ford embarked on the problem of identifying the source of volcanic ash used as temper in prehistoric Maya ceramics. Verification of the presence of glass shards and associated volcanic mineralogy in thin sections of Maya ceramics was straightforward and pointed to the Guatemala Highland volcanic chain. Considering seasonal wind rose patterns, target volcanoes include those from the area west of and including Guatemala City. Joint field research conducted in 1983 by Glicken and Ford in the limestone lowlands of Belize and neighboring Guatemala, 300 km north of the volcanic zone and 150 km from the nearest identified ash deposits, was unsuccessful in discovering local volcanic ash deposits. The abundance of the ash in common Maya ceramic vessels coupled with the difficulties of long-distance procurement without draft animals lead Glicken to suggest that ashfall into the lowlands would most parsimoniously explain prehistoric procurement; it literally dropped into their hands. A major archaeological problem with this explanation is that the use of volcanic ash occurring over several centuries of the Late Classic Period (ca. 600-900 AD). To accept the ashfall hypothesis for ancient Maya volcanic ash procurement, one would have to demonstrate a long span of consistent volcanic activity in the Guatemala Highlands for the last half of the first millennium AD. Should this be documented through careful petrographic, microprobe and tephrachronological studies, a number of related archaeological phenomena would be explained. In addition, the proposed model of volcanic activity has implications for understanding volcanism and potential volcanic hazards in Central America over a significantly longer time span than the historic period. These avenues are explored and a call for further collaborative research of this interdisciplinary problem is extended in this paper.

Arsenic Speciation and Cadmium Determination in Tobacco Leaves, Ash and Smoke.

Science.gov (United States)

Iwai, Takahiro; Chiba, Koichi; Narukawa, Tomohiro

2016-01-01

The concentrations of arsenic (As) and cadmium (Cd) in the tobacco leaves, ash and smoke of 10 kinds of cigarettes collected from different countries worldwide were determined by ICP-MS after microwave-assisted digestion. Total As and Cd concentrations in the tobacco leaves ranged from 0.20 to 0.63 and 1.8 to 9.9 mg kg(-1), respectively. By the speciation analysis of As in tobacco leaves and ash by HPLC-ICP-MS following acid extraction, arsenite [As(III)] and arsenate [As(V)] were determined and trace amounts of monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA), trimethylarsine oxide (TMAO), tetramethylarsonium (TeMA) and some unidentified As species were also found. Arsenic speciation for smoke absorbed in an aqueous solution was carried out. The sum of the As species in tobacco leaves, ash and smoke was in good agreement with the result of total As determination in each sample, and the recoveries of speciation were 100 ± 10%. The distributions and the behaviors of As species were clarified.

Current Methods to Detoxify Fly Ash from Waste Incineration

Energy Technology Data Exchange (ETDEWEB)

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

2004-07-01

vitrification, electric arc and melting in a secondary combustion chamber by adding coke as a heating source (coke bed melting furnaces) or residual carbon in the fly ash (Rotary surface melting furnace) are the most common methods. In general, vitrification processes require a high-energy input and are therefore relatively cost intensive. Locking the hazardous components into the matrix by a stabilization/solidification with cement is a common alternative to decontamination. Mixing the fly ash with cement or asphalt is widely used for the reuse of fly ash from coal incineration, but it requires careful attention to any leaching of heavy metals if applied to fly ash from waste incineration. Studies by mixing fly ash with cement at concentrations from 5 to 70 % showed, that in most cases an additional pretreatment step, e.g. washing in HNO{sub 3} solution, is necessary to receive acceptable leaching behaviour and required properties as building material. Related European regulations are currently pending. On the other hand, the use of fly ash as filler for asphalt does not require any pretreatment and is already commonly applied in some countries such as the Netherlands as a well-established method. Solvent extraction methods such as acidic extraction (3R-process) or combined basic and acidic extraction (MR-process) are also designed to remove the contaminants. The effectiveness of these methods is only moderate and a further thermal treatment is required to destroy the dioxins. These methods require relatively high amounts of chemicals and wastewater management. However, they are supposed to be relatively cost effective. Other treatment options that are being tested at laboratory scale such as microbiological treatment and supercritical extraction are optimistic but have no realistic practical relevance at this state.

Coal Ash Aerosol in East Asian Outflow as a Source for Oceanic Deposition of Iron and Other Metals

Science.gov (United States)

Anderson, J. R.; Hua, X.

2008-12-01

While ocean deposition of East Asian dust is given significant emphasis as a source of biologically-active trace elements, iron in particular, dust events are episodic and highly seasonal. There is, however, a constant source of aerosol that is chemically similar to dust (albeit amorphous in structure rather than crystalline) in the ash particles emitted from many hundreds of coal-fired power plants that are sited along the entire coastal region of China and Korea. The emission controls on these facilities vary widely and, in even cases of state-of-the-art emission controls, the secondary release of ash can be significant. There are of course even more small industrial and household sources of coal combustion emissions, in most cases with little or no emissions controls. Ash from a modern coal-fired power facility in Korea has been examined chemically and morphologically with electron microscopic techniques. As is characteristic of all such facilities, two principal types of ash are present: (1) flyash, silicate glass spheres that are emitted with the smoke and removed by electrostatic precipitators; and (2) bottom ash, "clinkers" and noncombustible material sticking to the furnace walls that are mixed with water and ground after cooling, then removed as a slurry to a dumping area. In addition, iron sulfide (pyrite) is a common constituent of coal and provides both a source of sulfur dioxide gas and also molten iron spherical particles in the ash. The iron spheres then are rapidly oxidized upon cooling. Bottom ash is a more complex material than flyash in that it contains more iron and other trace metals, plus it contains varying amounts of uncombusted carbon. The post-combustion handling of bottom ash can lead to significant emissions despite the fact that little or none goes out the stack. The iron oxide spheres can also be emitted by this secondary method. The concentrations of ash can be very high in close proximity to power plants (PM10 of several hundred

Strength Assessment of Controlled Low Strength Materials (CLSM) Utilizing Recycled Concrete Aggregate and Waste Paper Sludge Ash

OpenAIRE

Ridzuan, Ahmad Ruslan Mohd; Fauzi, Mohd Azrizal; Ghazali, Ezliana; Arshad, Mohd Fadzil; Fauzi, Mohd Afiq; Mohd Fauzi, Mohd Afiq

2013-01-01

This paper studies the strength development of low-strength material (CLSM) is controlled by using waste paper sludge ash (WPSA) in CLSM mixtures without adding Portland cement. Series of four (4) compounds which is the CLSM containing 5%, 10%, 20% and 30% of waste paper sludge ash (WPSA) as a substitute for Portland cement. CLSM cubes the sizes of 100mm x 100mm x 100mm compressive strength were tested at age 7, 14 and 28days. It was found that this activity contributes to strength developmen...

Bioleaching of trace metals from coal ash using local isolate from coal ash ponds

Directory of Open Access Journals (Sweden)

Pangayao Denvert

2018-01-01

Full Text Available Bioleaching of chromium, copper, manganese and zinc from coal ash were investigated using isolates from coal ash ponds particularly Psuedomonas spp. Six (6 different coal ash ponds were examined however, after initial screening Psuedomonas spp. were only present in three (3 coal ash ponds. Among the three coal ash ponds, results showed that eight (8 putative Pseudomonas spp. isolates were present that were identified using the Polymerase Chain Reaction (PCR. Using the eight putative Pseudomonas spp. for bioleaching at optimum conditions and 15 days, the pH value ranges from 8.26 to 8.84 which was basic in nature. Moreover, the maximum metal leached were 8.04% Cr, 12.05% Cu, 4.34% Mn and 10.63% Zn.

Degradation of Anthraquinone Dye Reactive Blue 4 in Pyrite Ash Catalyzed Fenton Reaction

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Milena Becelic-Tomin

2014-01-01

Full Text Available Pyrite ash (PA is created by burning pyrite in the chemical production of sulphuric acid. The high concentration of iron oxide, mostly hematite, present in pyrite ash, gives the basis for its application as a source of catalytic iron in a modified Fenton process for anthraquinone dye reactive blue 4 (RB4 degradation. The effect of various operating variables such as catalyst and oxidant concentration, initial pH and RB4 concentration on the abatement of total organic carbon, and dye has been assessed in this study. Here we show that degradation of RB4 in the modified Fenton reaction was efficient under the following conditions: pH=2.5; [PA]0=0.2 g L−1; [H2O2]0=5 mM and initial RB4 concentration up to 100 mg L−1. The pyrite ash Fenton reaction can overcome limitations observed from the classic Fenton reaction, such as the early termination of the Fenton reaction. Metal (Pb, Zn, and Cu content of the solution after the process suggests that an additional treatment step is necessary to remove the remaining metals from the water. These results provide basic knowledge to better understand the modified, heterogeneous Fenton process and apply the PA Fenton reaction for the treatment of wastewaters which contains anthraquinone dyes.

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

Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

Directory of Open Access Journals (Sweden)

BORISLAV GRUBOR

2003-02-01

Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

Experience with vertical down-fired, coal-fuelled, low emissions air heaters incorporating automatic ash removal

Energy Technology Data Exchange (ETDEWEB)

Keller, M.; Noble, R.K.; Keller, J. [Tulsa Combustion LLC, Tulsa, OK (United States)

2009-07-01

This paper discussed the conversion of a horizontally-oriented air heater system with a vertically-oriented pulverized coal-fuelled air heater system. The vertically-oriented heater was used for automatic de-ashing and avoiding the ash accumulation often seen in horizontally-oriented systems. The study showed that the use of the vertical system significantly reduced emissions of nitrous oxides (NO{sub x}), carbon monoxide (CO) and volatile organic compounds (VOCs). Slag and salt attacks on the refractory were also reduced. The vertical systems provided automatic ash removal and eliminated hot spots on the refractory. The potential for variations in composition was also reduced. It was concluded that the system's smaller footprint means that it can be used in retrofits and can be installed in small spaces. 12 figs.

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

Fly ash quality and utilization

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-01

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

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.

The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration after Invasion

Science.gov (United States)

Emerald ash borer (EAB) is an invasive Asian beetle that is destroying ash in forests over much of eastern North America because of the high susceptibility of our native ash and a lack of effective natural enemies. To increase mortality of EAB larvae and eggs, the USDA (FS, ARS and APHIS) is carryin...

Alkaline coal fly ash amendments are recommended for improving rice-peanut crops

Energy Technology Data Exchange (ETDEWEB)

Swain, D.K.; Ghosh, B.C. [Agricultural and Food Engineering Department, Indi an Inst. of Technology, Kharagpur, West Bengal (India); Rautaray, S.K. [RRLRRS, Gerua Via-Hajo, Dist-Kamrup, Assam (India)

2007-05-15

A field experiment investigating amendments of organic material including farmyard manure, paper factory sludge and crop residues combined with fly ash, lime and chemical fertilizer in a rice-peanut cropping system was conducted during 1997-98 and 1998-99 at the Indian Institute of Technology, Kharagpur, India. The soil was an acid lateritic (Halustaf) sandy loam. For rice, an N:P:K level of 90:26.2:33.3 kg/ha was supplied through the organic materials and chemical fertilizer to all the treatments except control and fly ash alone. The required quantities of organic materials were added to supply 30 kg N/ha and the balance amount of N, P and K was supplied through chemical fertilizer. Amendment materials as per fertilization treatments were incorporated to individual plots 15 days before planting of rice during the rainy season. The residual effects were studied on the following peanut crop with application of N:P:K at 30:26.2:33.3 kg/ha through chemical fertilizer alone in all treatments, apart from the control. An application of fly ash at 10 t/ha in combination with chemical fertilizer and organic materials increased the grain yield of rice by 11% compared to chemical fertilizer alone. The residual effect of both lime and fly ash applications combined with direct application of chemical fertilizer increased peanut yields by 30% and 24%, respectively, compared to chemical fertilizer alone. Treatments with fly ash or lime increased P and K uptake in both the crops and oil content in peanut kernel compared to those without the amendments. Alkaline coal fly ash proved to be a better amendment than lime for improving productivity of an acid lateritic soil and enriching the soil with P and K.

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

(refuse derived fuels), will most likely lead to increased leaching. This will be more prominent for oxyanions than for metals. In the evaluation of the application of coal fly ash in cement production or in partial cement replacement, it is important to assess the materials behaviour in recycling stages in unbound form besides its leaching behaviour of the intact product in its service life. This aspect has not been addressed before. If a material performs poorly from an environmental point of view in its recycling stages, one should be more critical in allowing (too) high levels of co-firing or too high mixing ratios of biomass. In general, the oxyanions will be more critical than most metals. The variability in several types of biomass is rather high. This holds limitations for plant operation and availability. Premixing of biomass during size reduction leads to more consistent input and thus to more constant ash quality. Co-firing may lead to increased Cr-VI levels in the fly ash due to oxidation of Cr, which is more prominently present in flue gas upon biomass co-firing than in case of regular coal firing. Elevated Cr-VI levels are more leachable. The following recommendations have been made: measurement of leaching behaviour of coal fly ash from co-firing of different biomass streams with a special emphasis on Cr-VI leachability; measurement of flue gas quality relative to pure coal combustion during co-firing of contaminated biomass streams; verification of durability of cement-based products containing coal fly ash with ash from biomass; evaluation of the leaching behaviour of recycling products from the primary uses of biomass ash or fly ash. 35 refs.

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

Permeability Characteristics of Compacted and Stabilized Clay with Cement, Peat Ash and Silica Sand

Directory of Open Access Journals (Sweden)

Seyed Esmaeil Mousavi

2016-06-01

Full Text Available The present paper investigates the influence of stabilization with cement, peat ash, and silica sand on permeability coefficient (kv of compacted clay, using a novel approach to stabilize the clay with peat ash as a supplementary material of cement in the compacted and stabilized soil. In order to assess the mentioned influence, test specimens of both untreated and stabilized soil have been tested in the laboratory so that their permeability could be evaluated. Falling head and one dimensional consolidation tests of laboratory permeability were performed on the clay specimens and the chemical compositions of the materials as well as microstructure of the stabilized soil with 18% cement, 2% peat ash, and 5% silica sand were investigated, using X-ray fluorescence and scanning electron microscopy respectively. Results show that for soil stabilization with up to 8% cement content (of the dry weight of the soil, the average value of coefficient of permeability (kv is very close to that of untreated soil, whereas the kv value decreases drastically for 18% cement under identical void ratio conditions. It is further revealed that addition of 18% cement, 2% peat ash, and 5% silica sand had decreased the coefficient of permeability by almost 2.2 folds after 24 h, while about 1.7 folds increase was observed in coefficient of permeability once 13.5% of cement, 1.5% of peat ash, and 20% of silica sand were added. The partial replacement of cement with the 2% peat ash can reduce the consumption of cement for soil stabilization.

Volcanic ash impacts on critical infrastructure

Science.gov (United States)

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

2012-01-01

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

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

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

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.

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.

Application of Coal Ash to Postmine Land for Prevention of Soil Erosion in Coal Mine in Indonesia: Utilization of Fly Ash and Bottom Ash

Directory of Open Access Journals (Sweden)

Shinji Matsumoto

2016-01-01

Full Text Available The increase in the number of coal-fired power plants with the increase in coal production and its consumption has caused the problem of the treatment of a large amount of coal ash in Indonesia. In the past studies, coal ash was applied to postmine land with the aim of improving soil conditions for plant growth; however, heavy rain in the tropical climate may cause soil erosion with the change in soil conditions. This study presents the effects of application of coal ash to postmine land on soil erosion by performing the artificial rainfall test as well as physical testing. The results indicate that the risk of soil erosion can be reduced significantly by applying the coal ash which consists of more than 85% of sand to topsoil in the postmine land at the mixing ratio of over 30%. Additionally, they reveal that not only fine fractions but also microporous structures in coal ash enhance water retention capacity by retaining water in the structure, leading to the prevention of soil erosion. Thus, the risk of soil erosion can be reduced by applying coal ash to topsoil in consideration of soil composition and microporous structure of coal ash.

Thermal and Ash Characterization of Indonesian Bamboo and Its Potential for Solid Fuel and Waste Valorization

Directory of Open Access Journals (Sweden)

Aprilina Purbasari

2016-08-01

Full Text Available Bamboo has been widely used in Indonesia for construction, handicrafts, furniture and other uses. However, the use of bamboo as a biomass for renewable energy source has not been extensively explored. This paper describes the thermal and ash characterization of three bamboo species found in Indonesia, i.e. Gigantochloa apus, Gigantochloa levis and Gigantochloa atroviolacea. Characterization of bamboo properties as a solid fuel includes proximate and ultimate analyses, calorific value measurement and thermogravimetric analysis. Ash characterization includes oxide composition analysis and phase analysis by X-Ray diffraction. The selected bamboo species have calorific value comparable with wood with low nitrogen and sulphur contents, indicating that they can be used as renewable energy sources. Bamboo ash contains high silicon so that bamboo ash has potential to be used further as building materials or engineering purposes. Ash composition analysis also indicates high alkali that can cause ash sintering and slag formation in combustion process. This implies that the combustion of bamboo requires the use of additives to reduce the risk of ash sintering and slag formation. Article History: Received May 15, 2016; Received in revised form July 2nd, 2016; Accepted July 14th, 2016; Available online How to Cite This Article: Purbasari, A., Samadhi, T.W. & Bindar, Y. (2016 Thermal and Ash Characterization of Indonesian Bamboo and its Potential for Solid Fuel and Waste Valorization. Int. Journal of Renewable Energy Development, 5(2, 95-100. http://dx.doi.org/10.14710/ijred.5.2.96-100 

Possibilities of utilizing power plant fly ashes

Directory of Open Access Journals (Sweden)

Mezencevová Andrea

2003-09-01

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

The Stabilization of Weathered Dolerite Aggregates with Cement, Lime, and Lime Fly Ash for Pavement Construction

Directory of Open Access Journals (Sweden)

Felix N. Okonta

2014-01-01

Full Text Available An experimental program was performed on weathered dolerite specimens stabilized by adding varying percentages of cement (4, 8, 12, and 16 % and lime (6 and 12 % and a combination of lime and fly ash (6% lime + 12% Fly ash and 12% lime + 12% Fly ash % by dry weight of soil. The strength was examined under three different curing methods, namely, membrane curing (MBC, alternate moist-air curing (MAC, and water curing (WAC, by conducting unconfined compressive strength (UCS tests. Simple polynomial and linear functions (regression models were used to define the relationships between the variables investigated. Membrane curing (MBC gave results close enough to the water curing (WAC to indicate that it can be confidently used on the field during pavement construction. From the results obtained, for class B (interurban collector and major rural roads pavement construction, addition of 8% cement was recommended for road base construction with stabilized WDA. Also the addition of 12 + 12% Lime and Fly Ash was recommended for road subbase construction with stabilized WDA. Stabilized WDA against the prejudiced myths would perform satisfactorily for base and subbase construction in both heavily trafficked and low volume roads with economic quantities of cement, lime, and fly ash in South Africa.

Development and characterisation of novel heterogeneous palm oil mill boiler ash-based catalysts for biodiesel production.

Science.gov (United States)

Ho, Wilson Wei Sheng; Ng, Hoon Kiat; Gan, Suyin

2012-12-01

Novel heterogeneous catalysts from calcium oxide (CaO)/calcined calcium carbonate (CaCO(3)) loaded onto different palm oil mill boiler ashes were synthesised and used in the transesterification of crude palm oil (CPO) with methanol to yield biodiesel. Catalyst preparation parameters including the type of ash support, the weight percentage of CaO and calcined CaCO(3) loadings, as well as the calcination temperature of CaCO(3) were optimised. The catalyst prepared by loading of 15 wt% calcined CaCO(3) at a fixed temperature of 800°C on fly ash exhibited a maximum oil conversion of 94.48%. Thermogravimetric analysis (TGA) revealed that the CaCO(3) was transformed into CaO at 770°C and interacted well with the ash support, whereas rich CaO, Al(2)O(3) and SiO(2) were identified in the composition using X-ray diffraction (XRD). The fine morphology size (<5 μm) and high surface area (1.719 m(2)/g) of the fly ash-based catalyst rendered it the highest catalytic activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Measurement of natural activity in peat ashes

International Nuclear Information System (INIS)

Suomela, J.

1985-01-01

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

Classification of pulverized coal ash

International Nuclear Information System (INIS)

Van der Sloot, H.A.; Van der Hoek, E.E.; De Groot, G.J.; Comans, R.N.J.

1992-09-01

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

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.)

An improved ashing procedure for biologic sample

Energy Technology Data Exchange (ETDEWEB)

Zongmei, Wu [Zhejiang Province Enviromental Radiation Monitoring Centre (China)

1992-07-01

The classical ashing procedure in muffle was modified for biologic samples. In the modified procedure the door of muffle was open in the duration of ashing process, the ashing was accelerated and the ashing product quality was comparable to that the classical procedure. The modified procedure is suitable for ashing biologic samples in large batches.

An improved ashing procedure for biologic sample

International Nuclear Information System (INIS)

Wu Zongmei

1992-01-01

The classical ashing procedure in muffle was modified for biologic samples. In the modified procedure the door of muffle was open in the duration of ashing process, the ashing was accelerated and the ashing product quality was comparable to that the classical procedure. The modified procedure is suitable for ashing biologic samples in large batches

Treatment of fly ash for use in concrete

Science.gov (United States)

Boxley, Chett [Park City, UT

2012-05-15

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Engineering properties of fly ash concrete

International Nuclear Information System (INIS)

Hilmi Mahmud

1999-01-01

This paper presents some of the engineering properties of Malaysian fly ash concrete. Workability, compressive, flexural, tensile splitting, drying shrinkage, elastic modulus and non destructive tests were performed on fly ash and control OPC concrete specimens. Data show that concrete containing 25% fly ash replacement of cement exhibit superior or similar engineering properties to that normal concrete without fly ash. These encouraging results demonstrated the technical merits of incorporating fly ash in concrete and should pave the way for wide scale use of this versatile material in the Malaysian construction industry. (author)

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

potash fertilizer containing, at most, 30% wood ash (course ash). Because of the high amounts of cadmium and copper, wood ash from our samples can only comprise a maximum of 28% when added to typically used potash fertilizers. Higher percentage of wood ash would exceed the cut-off value established by the German Fertilizer Ordinance (Duengemittelverordnung - DueMV). Conclusions: The application of wood ash on agricultural land and in private gardens is, rightfully so, highly regulated by law. However, the rules governing application of wood ash in the forest are much more lax. Determination of heavy metal content in wood ash cannot be used to determine compliance with DueMV standards because of the high content and fluctuating nature of heavy metals found. Recommendations and perspectives: Presently an alternative approach for classifying the ecologic risk of wood ash recycling is being devloped. (orig.)

Treatment of fly ash for use in concrete

Science.gov (United States)

Boxley, Chett; Akash, Akash; Zhao, Qiang

2013-01-08

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

Reactive Uptake of Sulfur Dioxide and Ozone on Volcanic Glass and Ash at Ambient Temperature

Science.gov (United States)

Maters, Elena C.; Delmelle, Pierre; Rossi, Michel J.; Ayris, Paul M.

2017-09-01

The atmospheric impacts of volcanic ash from explosive eruptions are rarely considered alongside those of volcanogenic gases/aerosols. While airborne particles provide solid surfaces for chemical reactions with trace gases in the atmosphere, the reactivity of airborne ash has seldom been investigated. Here we determine the total uptake capacity (NiM) and initial uptake coefficient (γM) for sulfur dioxide (SO2) and ozone (O3) on a compositional array of volcanic ash and glass powders at 25°C in a Knudsen flow reactor. The measured ranges of NiSO2 and γSO2 (1011-1013 molecules cm-2 and 10-3-10-2) and NiO3 and γO3 (1012-1013 molecules cm-2 and 10-3-10-2) are comparable to values reported for mineral dust. Differences in ash and glass reactivity toward SO2 and O3 may relate to varying abundances of, respectively, basic and reducing sites on these materials. The typically lower SO2 and O3 uptake on ash compared to glass likely results from prior exposure of ash surfaces to acidic and oxidizing conditions within the volcanic eruption plume/cloud. While sequential uptake experiments overall suggest that these gases do not compete for reactive surface sites, SO2 uptake forming adsorbed S(IV) species may enhance the capacity for subsequent O3 uptake via redox reaction forming adsorbed S(VI) species. Our findings imply that ash emissions may represent a hitherto neglected sink for atmospheric SO2 and O3.

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

. Additional calculations were made concerning the area of abandoned peat fields ready for after-use by afforestation. The main part of the site selection was made in five steps. First, the non-productive sites (which produce less than 1 m{sup 3}/ha/yr) were rejected. Also sites with peat cover shallower than 30 cm were excluded. In the next step it was decided to restrict the ash fertilization to areas with drains in good condition, and to sites where the field vegetation was dominated by 'better shrubs' (Vaccinium myrtillus, V. vitis idaea, Equisetum silvaticum, and tall sedges) or 'low sedge' (Eriophorum vaginatum, Scirpus caespitosus, and other low Cyperaceae plants). Finally, open areas, seedling stands, and young forests were rejected in favour of un-thinned and thinned mid-rotation, and mature and old stands. According to these selection criteria the most suitable sites for ash fertilization are drained, productive peatlands characterized by thinning stands or older stands where the field vegetation is dominated by better shrubs or low sedge plants. The selection comprises 190,000 ha. Most of these areas are located in North Sweden (90,000 ha), whereas Central and South Sweden accounted for 30,000 ha and 70,000 ha, respectively. In addition to this, 2,000-3,000 ha of abandoned peat fields ready for afforestation should be added within a period of about 5 years. The requirement for phosphorus when peatland forests are fertilized is 40-50 kg/ha. From this, and from studies on the variation of phosphorus content and bulk density of wood ash of various origins, it can be calculated that a proper ash fertilization dose would be 3-5 t/ha. The nutrient content in the ash may however often prove lower than in the reported studies, in which case larger doses than 5 t/ha would be required. The present annual production of bio-ash in Sweden is about 250,000-300,000 tonnes. If it were desired to amend all sites (190,000 ha) identified in this study by using 5

Soil quality in a cropland soil treated with wood ash containing charcoal

Science.gov (United States)

Omil, Beatriz; Balboa, Miguel A.; Fonturbel, M. Teresa; Gartzia-Bengoetxea, Nahia; Arias-González, Ander; Vega, Jose A.; Merino, Agustin

2014-05-01

. Three years after applications the SOM content increased lightly in the treatment receiving more than 16 Mg ha-1 of wood ash. SOM in the treated soils displayed a higher degree of aromaticity than in the untreated soils, indicating a gain in more stable SOM compounds probably as a consequence of the charcoal application. However, both methods also revealed increases in labile C compounds, probably due to the carbohydrates added through root system. Microbial biomass-C and soil respiration increased significantly. The treatments also led to increases in the functional diversity indices. The amended soils showed greater utilization of substrates and the ability of soil bacteria to utilize different C resources was also greatly altered. The application of mixed wood ash did not lead to any difference in MWD, which was around 6 mm in all cases. The application of 16 Mg fly wood ash ha-1 increased significantly the hydraulic conductivity (4.07 cmh-1) when compared with in control plots (1.3 cmh-1) and mixed ash plots (1.52 and 2.45 cmh-1, 16 Mg and 32 Mg respectively). However, air-filled porosity was not higher in 16 Mg fly ash plots. AWC was not improved by wood ash application.

Flue gas desulphurization in a spray tower with de-coupled recycling of soda ash

Energy Technology Data Exchange (ETDEWEB)

Liebgott, H.

1983-05-01

RD project to develop a ''dry'' process for the desulphurization of flue gases. The process is based on a desulphurization step with a solution of soda ash which is sprayed into the flue gas. The gas is cooled by evaporation but its temperature is still higher than the dew point; reheating is not necessary. The product of the desulphurization is a dry mixture of sodium sulphite and -carbonate. It is intended to reprocess this powder to soda in a central plant - serving several power stations. First sulphite is oxidized to sulphate, which in turn is reacted with calcium chloride to form calcium sulphate and sodium chloride. The latter is introduced into the Solvay-soda ash process which yields calcium chloride as a by-product. Tests were carried out for the desulphurization step and the oxidation of sulphite. The desulphurization tests resulted in poor degrees of SO/sub 2/-removal even with high stoichiometric ratios of soda ash to sulphur dioxide. The preliminary estimates of process economics made before start of experimental work could not be verified. Furthermore, during work on the project, new processes were revealed whereby flue gas is desulphurized in a spray-drying apparatus with a slurry of calcium hydroxide. In an extension of the project, tests were carried out which confirmed these findings. The project was abandoned.

Coal fly ash based carbons for SO2 removal from flue gases.

Science.gov (United States)

Rubio, B; Izquierdo, M T

2010-07-01

Two different coal fly ashes coming from the burning of two coals of different rank have been used as a precursor for the preparation of steam activated carbons. The performance of these activated carbons in the SO(2) removal was evaluated at flue gas conditions (100 degrees C, 1000 ppmv SO(2), 5% O(2), 6% H(2)O). Different techniques were used to determine the physical and chemical characteristics of the samples in order to explain the differences found in their behaviour. A superior SO(2) removal capacity was shown by the activated carbon obtained using the fly ash coming from a sub-bituminous-lignite blend. Experimental results indicated that the presence of higher amount of certain metallic oxides (Ca, Fe) in the carbon-rich fraction of this fly ash probably has promoted a deeper gasification in the activation with steam. A more suitable surface chemistry and textural properties have been obtained in this case which explains the higher efficiency shown by this sample in the SO(2) removal. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Determining the ash content of coal flotation tailings using an MPOF optical ash meter

Energy Technology Data Exchange (ETDEWEB)

Sikora, T; Sliwa, J

1982-01-01

The block layout, a description of the design and principles of operation of an automatic optical, continuous action MPOF type ash meter are presented. The difference in the optical properties of coal and rock is used in the ash meter. The identification of the ash content is conducted on the basis of the spectral characteristics of reflection of a finely dispersed aqueous coal and rock suspension.

Low temperature setting iron phosphate ceramics as a stabilization and solidification agent for incinerator ash contaminated with transuranic and RCRA metals

International Nuclear Information System (INIS)

Medvedev, P.G.; Hansen, M.; Wood, E.L.; Frank, S.M.; Sidwell, R.W.; Giglio, J.J.; Johnson, S.G.; Macheret, J.

1997-01-01

Incineration of combustible Mixed Transuranic Waste yields an ash residue that contains oxides of Resource Conservation and Recovery Act (RCRA) and transuranic metals. In order to dispose of this ash safely, it has to be solidified and stabilized to satisfy appropriate requirements for repository disposal. This paper describes a new method for solidification of incinerator ash, using room temperature setting iron phosphate ceramics, and includes fabrication procedures for these waste forms as well as results of the MCC-1 static leach test, XRD analysis, scanning electron microscopy studies and density measurements of the solidified waste form produced

Arsenic removal from water using a novel amorphous adsorbent developed from coal fly ash.

Science.gov (United States)

Zhang, Kaihua; Zhang, Dongxue; Zhang, Kai

2016-01-01

A novel effective adsorbent of alumina/silica oxide hydrate (ASOH) for arsenic removal was developed through simple chemical reactions using coal fly ash. The iron-modified ASOH with enhancing adsorption activity was further developed from raw fly ash based on the in situ technique. The adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectrometry, scanning electron micrograph, laser particle size and Brunauer-Emmet-Teller surface area. The results show that the adsorbents are in amorphous and porous structure, the surface areas of which are 8-12 times that of the raw ash. The acidic hydrothermal treatment acts an important role in the formation of the amorphous structure of ASOH rather than zeolite crystal. A series of adsorption experiments for arsenic on them were studied. ASOH can achieve a high removal efficiency for arsenic of 96.4% from water, which is more than 2.5 times that of the raw ash. Iron-modified ASOH can enhance the removal efficiency to reach 99.8% due to the in situ loading of iron (Fe). The condition of synthesis pH = 2-4 is better for iron-modified ASOH to adsorb arsenic from water.

Mechanical Properties of High Volume Fly Ash Concrete Reinforced with Hybrid Fibers

Directory of Open Access Journals (Sweden)

Rooban Chakravarthy

2016-01-01

Full Text Available Fly ash substitution to cement is a well-recognized approach to reduce CO2 emissions. Although fly ash concrete is prone to brittle behavior, researchers have shown that addition of fibers could reduce brittle behavior. Previous research efforts seem to have utlised a single type of fiber or two types of fibers. In this research, three types of fibers, steel, polypropylene, and basalt as 0%, 0.50%, 0.75%, and 1% by volume of concrete, were mixed in varying proportions with concrete specimens substituted with 50% fly ash (class F. All specimens were tested for compressive strength, indirect tensile strength, and flexural strength over a period of 3 to 56 days of curing. Test results showed that significant improvement in mechanical properties could be obtained by a particular hybrid fiber reinforcement combination (1% steel fiber, 0.75% polypropylene fiber, and 0.75% basalt fiber. The strength values were observed to exceed previous research results. Workability of concrete was affected when the fiber combination exceeded 3%. Thus a limiting value for adding fibers and the combination to achieve maximum strengths have been identified in this research.

Electrodialytic removal of heavy metals from fly ashes

DEFF Research Database (Denmark)

Pedersen, Anne Juul

2002-01-01

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

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

Energy Technology Data Exchange (ETDEWEB)

Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: aanaqvi@kfupm.edu.sa; Garwan, M.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Maslehuddin, M. [Center for Engineering Research, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khateeb-ur-Rehman; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2009-09-15

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

International Nuclear Information System (INIS)

Naqvi, A.A.; Garwan, M.A.; Maslehuddin, M.; Nagadi, M.M.; Al-Amoudi, O.S.B.; Khateeb-ur-Rehman,; Raashid, M.

2009-01-01

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5-80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42 MeV gamma-rays from calcium and 4.94 MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.

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

Energy Technology Data Exchange (ETDEWEB)

Manz, O.E.

1995-12-01

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

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 effect of water binder ratio and fly ash on the properties of foamed concrete

Science.gov (United States)

Saloma, Hanafiah, Urmila, Dea

2017-11-01

Foamed concrete is a lightweight concrete composed by cement, water, fine aggregate and evenly distributed foam. Foamed concrete is produced by adding foam to the mixture. The function of foam is to create air voids in the mixture, so the weight of the concrete becomes lighter. The foaming agent is diluted in water then given air pressure by foam generator to produce foam. This research utilizes coal combustion, which is fly ash as cementitious material with a percentage of 0%, 10%, 15%, and 20%. The purpose of the research is to examine the effect of water binder ratio 0.425, 0.450, 0.475, and 0.500 using fly ash on the properties of foamed concrete. Fresh concrete tests include slump flow and setting time test while hardened concrete tests include density and compressive strength. The maximum value of slump flow test result is 59.50 cm on FC-20-0.500 mixture with w/b = 0.500 and 20% of fly ash percentage. The results of the setting time tests indicate the fastest initial and final time are 335 and 720 minutes, respectively on FC-0-0.425 mixture with w/b = 0.425 without fly ash. The lowest density is 978.344 kg/m3 on FC-20-0.500 mixture with w/b = 0.500 and 20% of fly ash percentage. The maximum compressive strength value is 4.510 MPa at 28 days on FC-10-0.450 mixture with w/b = 0.450 and 10% of fly ash percentage.

The future of volcanic ash-aircraft interactions from technical and policy perspectives

Science.gov (United States)

Casadevall, T. J.; Guffanti, M.

2010-12-01

Since the advent of jet-powered flight in the 1960s, the threat of volcanic ash to aviation operations has become widely recognized and the mitigation of this threat has received concerted international attention. At the same time the susceptibility to operational disruption has grown. Technical improvements to airframes, engines, and avionic systems have been made in response to the need for improved fuel efficiency and the demand for increased capacity for passenger and freight traffic. Operational demands have resulted in the growth of extended overseas flight operations (ETOPS), increased flight frequency on air traffic routes, and closer spacing of aircraft on heavily traveled routes. The net result has been great advances in flight efficiency, but also increased susceptibility to flight disruption, especially in heavily traveled regions such as North Atlantic-Europe, North America, and the North Pacific. Advances in ash avoidance procedures, pilot and air manager training, and in detection of ash-related damage and maintenance of aircraft and engines have been spurred by noteworthy eruptions such as Galunggung, Indonesia, 1982; Redoubt, Alaska, 1989-1990; and Pinatubo, Philippines, 1991. Comparable advances have been made in the detection and tracking of volcanic ash clouds using satellite-based remote sensing and numerical trajectory forecast models. Following the April 2010 eruption of Eyjafjallajökull volcano, Iceland, the global aviation community again focused attention on the issue of safe air operations in airspace affected by volcanic ash. The enormous global disruption to air traffic in the weeks after the Eyjafjallajökull eruption has placed added emphasis for the global air traffic management system as well as on the equipment manufacturers to reevaluate air operations in ash-affected airspace. Under the leadership of the International Civil Aviation Organization and the World Meteorological Organization, efforts are being made to address this

Hazards Associated With Recent Popocatepetl Ash Emissions

Science.gov (United States)

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

2013-05-01

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

[Effects of sulphur compounds on the volatile characteristics of heavy metals in fly ash from the MSW and sewage sludge co-combustion plant during the disposal process with higher temperature].

Science.gov (United States)

Liu, Jing-Yong; Sun, Shui-Yu

2012-11-01

Fly ash sample was collected from a MSW co-combustion with sewage sludge plant and the volatilization of heavy metals Pb, Cd, Cu and Zn was investigated before and after the water washing of fly ash, meanwhile, the influence of adding different sulphur compounds (S, NaS, Na2 SO3, Na2 SO4) on the volatilization of heavy metals was studied. The results showed that the contents of Zn, Pb and Mn were high, the Ni content was low and the Cd content reached 29.4 mg x kg(1). The contents of Pb, Cu, Zn increased, while that of Cd reduced in the fly ash after water washing. TG-DTG curves of fly ash showed highest weight loss in ranges of 579-732 degrees C and 949-1 200 degrees C, with 690 degrees C and 1 154 degrees C as the inflection point temperatures. The volatilization of different heavy metals showed great difference in the volatilization rate, following the order of Pb > Cd > Zn > Cu, in which the volatilization rate of Pb was more than 80% and that of Cu was less than 30%. After water washing, the volatilization of different heavy metals showed great difference in the volatilization rate, with the order of Zn > Pb > Cd > Cu, in which the volatilization rate of Zn was more than 20%. With the pretreatment of adding Na2 SO3 and Na2 SO4, the evaporation rates of heavy metals (Cu, Pb, Zn, Cd) were significantly decreased. After adding S, the evaporation rate of Zn was reduced, whereas the addition of Na2S reduced the evaporation rates of Cd and Zn. The evaporation rates of the four heavy metals were all reduced after adding Na2S in the washed fly ash. The evaporation rates of Cu and Zn were reduced with addition of S and Na2SO3 and the evaporation rate of Cd was reduced by adding the four sulfides. The results can provide a basis for the harmless disposal and maximized resource utilization and recycling of fly ash.

Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

Science.gov (United States)

Robert, C. G.; Ayob, A.; Zaki, M. F. Muhammad; Razali, M. E.; Lew, E. V.; Hong, P. Y.

2018-03-01

Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA) and bottom ash (BA) mixtures with difference component percentage treated with sodium lauryl sulphate (SLS) and polyvinyl alcohol (PVA) at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

Directory of Open Access Journals (Sweden)

Robert C.G.

2018-01-01

Full Text Available Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA and bottom ash (BA mixtures with difference component percentage treated with sodium lauryl sulphate (SLS and polyvinyl alcohol (PVA at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

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.

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil.

Science.gov (United States)

Mollon, L C; Norton, G J; Trakal, L; Moreno-Jimenez, E; Elouali, F Z; Hough, R L; Beesley, L

2016-11-01

Heavy metal(loid) rich ash (≤10,000 mg kg -1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1-3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash. The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits. The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study on the effect of different concentration of Spirulina platensis paste added into dried noodle to its quality characteristics

Science.gov (United States)

Agustini, T. W.; Ma'ruf, W. F.; Widayat; Wibowo, B. A.; Hadiyanto

2017-02-01

High nutritional content of microalgae S. platensis is very good for human health especially for its protein and β-carotene. These compounds can be used for improving quality of food from nutritional point of view. This study was designed to observe the effect of different concentration of S. platensis paste to dried noodle quality based on physical, chemical and sensory perspectives. Material used in this study was S. platensis powder obtained from CV Neoalgae, Sukoharjo. The best treatment observed from preliminary study was then used for further study and compared to control treatment (without added S. platensis paste). The dried noodle resulted was then analyzed for elasticity, chemical (β-carotene, water, protein, ash, fat and carbohydrate) and sensory (hedonic). Parametric data obtained were analyzed using t-Test while non-parametric data was analyzed using Kruskal-Wallis followed by Multiple Comparison test. The study showed that dried noodle added with 9% S. platensis paste give significant effect (P<0.05) on elasticity; β-carotene, water, protein, ash, fat and carbohydrate and also sensory (hedonic). Dried noodle without added S. platensis paste has lower in β-carotene and protein compared to that of added S. platensis paste with the value of 0.06 mg/100 gr and 17.51 mg/100gr (β-carotene) and 8.88% and 38.6% (protein), respectively. Those, chemical composition of dried noodle added with S. platensis comply with Indonesian National Standard in term of protein, water, and ash content with sensory of 7.26 ≤ μ ≤ 7.63. Addition of S. platensis can significantly increase the nutritional of dried noodle especially protein (by 4 times) and β-carotene.

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 ...

Effect of aggregate structure on VOC gas adsorption onto volcanic ash soil.

Science.gov (United States)

Hamamoto, Shoichiro; Seki, Katsutoshi; Miyazaki, Tsuyoshi

2009-07-15

The understanding of the gaseous adsorption process and the parameters of volatile organic compounds such as organic solvents or fuels onto soils is very important in the analysis of the transport or fate of these chemicals in soils. Batch adsorption experiments with six different treatments were conducted to determine the adsorption of isohexane, a gaseous aliphatic, onto volcanic ash soil (Tachikawa loam). The measured gas adsorption coefficient for samples of Tachikawa loam used in the first three treatments, Control, AD (aggregate destroyed), and AD-OMR (aggregate destroyed and organic matter removed), implied that the aggregate structure of volcanic ash soil as well as organic matter strongly enhanced gas adsorption under the dry condition, whereas under the wet condition, the aggregate structure played an important role in gas adsorption regardless of the insolubility of isohexane. In the gas adsorption experiments for the last three treatments, soils were sieved in different sizes of mesh and were separated into three different aggregate or particle size fractions (2.0-1.0mm, 1.0-0.5mm, and less than 0.5mm). Tachikawa loam with a larger size fraction showed higher gas adsorption coefficient, suggesting the higher contributions of macroaggregates to isohexane gas adsorption under dry and wet conditions.

Attraction of the emerald ash borer to ash trees stressed by girdling, herbicide treatment, or wounding

Science.gov (United States)

Deborah McCullough; Therese Poland; David. Cappaert

2009-01-01

New infestations of emerald ash borer, Agrilus planipennis Fairmaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash (Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling (bark and phloem removed...

Ash in fire affected ecosystems

Science.gov (United States)

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

2015-04-01

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

Formation and utilization of fly ash

Energy Technology Data Exchange (ETDEWEB)

Vargyai, J

1974-01-01

General problems of slag and fly ash formation and utilization are discussed. The ever-increasing energy demand, and the comeback of coal as an energy carrier in power plants call for efficient solutions to the problem of slag and fly ash. Slag and fly ash are used for concrete in which they partly replace cement. Other possible uses are the amelioration of acid soils, fireclay manufacture, road construction, and tiles. It is possible to recover metals, such as vanadium, iron, aluminum, and radioactive materials from certain types of fly ash and slag. The utilization of fly ash is essential also with respect to the abatement of entrainment from dumps.

Associative properties of 137Cs in biofuel ashes

International Nuclear Information System (INIS)

Ravila, A.; Holm, E.

1999-01-01

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

Production of no-carrier-added {sup 123}I via heavy-ion activation of natural antimony oxide

Energy Technology Data Exchange (ETDEWEB)

Maji, S. [The Univ. of Burdwan (India). Dept. of Chemistry; Lahiri, S. [Saha Institute of Nuclear Physics, Kolkata (India). Chemical Sciences Div.

2007-07-01

Activation of natural Sb{sub 2}O{sub 3} with 48 MeV {sup 7}Li{sup 3+} beam results in the formation of no-carrier-added {sup 123}I in the matrix along with the radionuclides {sup 123,125}Xe and {sup 122}Sb. The {sup 123}I yield amounts to about 400 kBq/{mu}Ah and the radionuclidic impurity of {sup 124}I to {proportional_to}1.2% of {sup 123}I. Attempts to separate no-carrier-added iodine from bulk antimony target involved liquid-liquid extraction with TOA and HDEHP as well as precipitation of Sb{sub 2}S{sub 3} with thioacetamide. The precipitation technique was found to be the most effective for quantitative separation of {sup 123}I from the bulk antimony oxide target. (orig.)

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.

Biosynthesis of nano cupric oxide on cotton using Seidlitzia rosmarinus ashes utilizing bio, photo, acid sensing and leaching properties.

Science.gov (United States)

Bashiri Rezaie, Ali; Montazer, Majid; Rad, Mahnaz Mahmoudi

2017-12-01

In this research, a facile, rapid and eco-friendly method is introduced for synthesis and loading of cupric oxide on cellulosic chains of cotton fabric with functional properties. Seidlitzia rosmarinus ashes and copper acetate were employed as a natural source of alkaline and metal salt without further chemical materials. The treated samples indicated very good antibacterial activities toward both pathogen Staphylococcus aureus as Gram-positive and Escherichia coli as Gram-negative bacteria. Significant self-cleaning properties against degradation of methylene blue stain under UV irradiation were found. The sensing properties of high concentrated inorganic and organic acids such as sulfuric and formic acids based on colorimetric alterations of the treated fabrics were also confirmed showing acid leaching effects of the treated fabrics. Further, the treated samples showed coloring effects with an enhancement on the physio-mechanical properties including tensile strength, crease recovery angle and hydrophobocity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review of ecosystem level impacts of emerald ash borer on black ash wetlands: What does the future hold?

Science.gov (United States)

Randall K. Kolka; Anthony W. D' Amato; Joseph W. Wagenbrenner; Robert A. Slesak; Thomas G. Pypker; Melissa B. Youngquist; Alexis R. Grinde; Brian J. Palik

2018-01-01

The emerald ash borer (EAB) is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western...

Variation in the Volatile Profiles of Black and Manchurian Ash in Relation to Emerald Ash Borer Oviposition Preferences.

Science.gov (United States)

Rigsby, Chad M; McCartney, Nathaniel B; Herms, Daniel A; Tumlinson, James H; Cipollini, Don

2017-08-01

Emerald ash borer (EAB; Agrilus planipennis) is a devastating pest of ash (Fraxinus spp.) in its invaded range in North America. Its coevolved Asian hosts are more resistant and less preferred for oviposition than susceptible North American species. We compared EAB oviposition preferences and bark and canopy volatile organic compound (VOC) emissions of resistant Manchurian ash and susceptible black ash, and examined relationships between VOC profiles and oviposition. In the field, black ash was highly preferred for oviposition while no eggs were laid on Manchurian ash, and we found clear differences in the VOC profiles of Manchurian and black ash. We detected 78 compounds emitted from these species, including 16 compounds that elicited EAB antennal activity in prior studies. Four compounds were unique to black and 11 to Manchurian ash. Emission rates of 14 canopy and 19 bark volatiles varied among the two species, including four previously reported as antennally active. Specifically, 7-epi-sesquithujene (bark) emissions were greater from black ash, while β-caryophyllene (canopy), linalool (bark), and α-cubebene (bark) were emitted at higher rates by Manchurian ash. No relationships were found between the emission rate of any single compound or group of compounds (e.g. monoterpenes) suggesting that preference may be based on complex profile combinations. This is the first study to directly compare VOCs of black and Manchurian ash as well as the first to examine bark- and canopy-specific VOCs. The unique bark and canopy VOC profiles of these two species implicates potentially important variation in VOCs between a closely related resistant and susceptible species that provides a foundation for future studies of host preferences of EAB.

Field trial of a pair production gauge for the on-line determination of ash in coal on a conveyor belt

International Nuclear Information System (INIS)

Millen, M.J.; Sowerby, B.D.; Rafter, P.T.; Ellis, W.K.; Gravitis, V.L.; Howells, E.; McLennan, T.D.; Muldoon, L.J.

1984-01-01

The ash content of coal can be determined by a method based on pair production. Coal is irradiated with high energy γ-rays and the resulting 0.511 MeV annihilation and Compton scattered γ-rays are measured. The pair production (PP) technique has been previously proved in the laboratory on static bulk samples and in the field on high-throughput sample by-lines. In the present paper, a plant test to assess the PP gauge for direct on-line conveyor belt analysis is described. This test was undertaken on the recirculating coal facility at the pilot plant coal washery at the BHP Steel Works, Newcastle, New South Wales. Seven Hunter Valley coals with ash in the range 7.5-33 wt% were circulated around the conveyor loop, and scanned by both PP and low energy γ-ray transmission (LET) gauges. Samples were measured on-belt as a function of sample depth, compaction, moisture and particle size. The mass per unit area of coal on the belt was varied in the range 40-210 kg m -2 . The r.m.s. deviation between PP gauge ash and chemical laboratory ash was 1.07 wt% ash for 370 individual on-belt measurements on coal of mass per unit area greater than 60 kg m -2 ad 0.45 wt% ash for the mean ash of each sample. (author)

Clay Stabilization Using the Ash of Mount Sinabung in Terms of the Value of California Bearing Ratio (CBR)

Science.gov (United States)

Hastuty, I. P.; Roesyanto, R.; Napitupulu, S. M. A.

2018-02-01

Most areas in Indonesia consist of clay soils with high plasticity so that to meet technical requirements the soil needs improvement, which is known as soil stabilization.There are three ways of soil stabilization process, i.e. mechanical, physical and chemical. In this study, chemical stabilization was performed, that was by adding stabilizing agents to the soil. The stabilizing agent used was the ash of Mount Sinabung. Since 2010 until now, Sinabung Mountain is still experiencing eruption that produces a lot of volcanic ash and it inconveniences the environment. So, it is expected that this research will be able to optimize the utilization of Sinabung ash. The purpose of this study was to investigate the effect of the addition of Mount Sinabung ash to CBR (California Bearing Ratio) value, to determine the effect of the curing time of one day and fourteen days mixture on the CBR value, and to find the mixed content with effective curing time to produce the largest CBR value. Based on this study, the soil type CL (Clay - Low Plasticity) was obtained, based on the classification of USCS (Unified Soil Classification System) and categorized as A-6 (6) based on the classification of AASHTO (American Association of State Highway and Transportation officials) with the most effective mixed stabilizer material which was the variation of 10% Mount Sinabung ash with fourteen days of curing time. The CBR value resulted from the mixture of 10% Sinabung ash that was cured within fourteen days was 8.95%. By the increase of the content of the Sinabung ash, the CBR value always improved to the level of 10%, Sinabung ash then decreased and became constant at the mixture of higher volcanic ash mixture but remained above the CBR value of the original soil.

Optimizing Use of Girdled Ash Trees for Management of Low-Density Emerald Ash Borer (Coleoptera: Buprestidae) Populations.

Science.gov (United States)

Siegert, Nathan W; McCullough, Deborah G; Poland, Therese M; Heyd, Robert L

2017-06-01

Effective survey methods to detect and monitor recently established, low-density infestations of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), remain a high priority because they provide land managers and property owners with time to implement tactics to slow emerald ash borer population growth and the progression of ash mortality. We evaluated options for using girdled ash (Fraxinus spp.) trees for emerald ash borer detection and management in a low-density infestation in a forested area with abundant green ash (F. pennsylvanica). Across replicated 4-ha plots, we compared detection efficiency of 4 versus 16 evenly distributed girdled ash trees and between clusters of 3 versus 12 girdled trees. We also examined within-tree larval distribution in 208 girdled and nongirdled trees and assessed adult emerald ash borer emergence from detection trees felled 11 mo after girdling and left on site. Overall, current-year larvae were present in 85-97% of girdled trees and 57-72% of nongirdled trees, and larval density was 2-5 times greater on girdled than nongirdled trees. Low-density emerald ash borer infestations were readily detected with four girdled trees per 4-ha, and 3-tree clusters were as effective as 12-tree clusters. Larval densities were greatest 0.5 ± 0.4 m below the base of the canopy in girdled trees and 1.3 ± 0.7 m above the canopy base in nongirdled trees. Relatively few adult emerald ash borer emerged from trees felled 11 mo after girdling and left on site through the following summer, suggesting removal or destruction of girdled ash trees may be unnecessary. This could potentially reduce survey costs, particularly in forested areas with poor accessibility. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Simultaneous adsorption of dyes and heavy metals from multicomponent solutions using fly ash

International Nuclear Information System (INIS)

Visa, Maria; Bogatu, Cristina; Duta, Anca

2010-01-01

In wastewaters originating from dye industry there are amounts of dyes (very common methyl orange, methylene blue-MB) and heavy metals (cadmium, copper, nickel mainly from the organo-metallic dyes). They tend to adsorb in a competitive process and modify the substrate. Advanced removal is usually proposed via adsorption and the use of modified fly ash as a substrate is sustainable solution. The main constituents of fly ash (silica, alumina, iron oxide and un-burned carbon), are the priority compounds which favour the heavy metal adsorption and are active sites in dyes' adsorption processes. The paper studies the effect of MB adsorbed on the fly ash surface on the removal efficiency of cadmium, copper and nickel ionic species from complex, multi-cationic dye solutions. The adsorption efficiency and kinetics are evaluated from the complex, multicomponent systems and possible influences are discussed. High efficiencies are obtained at low heavy metal concentrations (as it is the real case for the dyes industry) whereas at medium values, competitive processes lower the individual efficiencies of copper, nickel or cadmium from mixtures.

Volcanic ash dosage calculator: A proof-of-concept tool to support aviation stakeholders during ash events

Science.gov (United States)

Dacre, H.; Prata, A.; Shine, K. P.; Irvine, E.

2017-12-01

The volcanic ash clouds produced by Icelandic volcano Eyjafjallajökull in April/May 2010 resulted in `no fly zones' which paralysed European aircraft activity and cost the airline industry an estimated £1.1 billion. In response to the crisis, the Civil Aviation Authority (CAA), in collaboration with Rolls Royce, produced the `safe-to-fly' chart. As ash concentrations are the primary output of dispersion model forecasts, the chart was designed to illustrate how engine damage progresses as a function of ash concentration. Concentration thresholds were subsequently derived based on previous ash encounters. Research scientists and aircraft manufactures have since recognised the importance of volcanic ash dosages; the accumulated concentration over time. Dosages are an improvement to concentrations as they can be used to identify pernicious situations where ash concentrations are acceptably low but the exposure time is long enough to cause damage to aircraft engines. Here we present a proof-of-concept volcanic ash dosage calculator; an innovative, web-based research tool, developed in close collaboration with operators and regulators, which utilises interactive data visualisation to communicate the uncertainty inherent in dispersion model simulations and subsequent dosage calculations. To calculate dosages, we use NAME (Numerical Atmospheric-dispersion Modelling Environment) to simulate several Icelandic eruption scenarios, which result in tephra dispersal across the North Atlantic, UK and Europe. Ash encounters are simulated based on flight-optimal routes derived from aircraft routing software. Key outputs of the calculator include: the along-flight dosage, exposure time and peak concentration. The design of the tool allows users to explore the key areas of uncertainty in the dosage calculation and to visualise how this changes as the planned flight path is varied. We expect that this research will result in better informed decisions from key stakeholders during

Proceedings of symposium on ash in North America

Science.gov (United States)

Charles H. Michler; Matthew D., eds. Ginzel

2010-01-01

Includes 5 papers and 30 abstracts covering topics related to the biology and ecology of the ash species, ash utilization and management, emerald ash borer, and other threats to ash, and genetics and conservation of ash species. A paper titled "Population-level variation of Fraxinus americana L. is influenced by climate...

Factors affecting the survival of ash (Fraxinus spp.) trees infested by emerald ash borer (Agrilus planipennis)

Science.gov (United States)

Kathleen S. Knight; John P. Brown; Robert P. Long

2013-01-01

Emerald ash borer (Agrilus planipennis) (EAB), an Asian woodboring beetle accidentally introduced in North America, has killed millions of ash (Fraxinus spp.) trees and is spreading rapidly. This study examined the effects of tree- and site-level factors on the mortality of ash trees in stands infested by EAB in OH, USA. Our data...

Use of unwounded ash trees for the detection of emerald ash borer adults: EAB landing behavior

Science.gov (United States)

Jordan M. Marshall; Melissa J. Porter; Andrew J. Storer

2011-01-01

Incorporation of multiple trapping techniques and sites within a survey program is essential to adequately identify the range of emerald ash borer (EAB) (Agrilus planipennis Fairmaire) infestation. Within natural forests, EAB lands on stick band traps wrapped around girdled ash trees at a rate similar to that on unwounded ash trees. The objective of...

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

Science.gov (United States)

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

2014-04-01

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability. © 2013 John Wiley & Sons Ltd.

Review of Ecosystem Level Impacts of Emerald Ash Borer on Black Ash Wetlands: What Does the Future Hold?

Directory of Open Access Journals (Sweden)

Randall K. Kolka

2018-04-01

Full Text Available The emerald ash borer (EAB is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western Great Lakes region. Using two companion studies that are simulating short- and long-term EAB infestations and what is known from the literature, we synthesize our current limited understanding and predict anticipated future impacts of EAB on black ash wetlands. A key response to the die-back of mature black ash will be higher water tables and the potential for flooding and resulting changes to both the vegetation and animal communities. Although seedling planting studies have shown some possible replacement species, little is known about how the removal of black ash from the canopy will affect non-ash species growth and regeneration. Because black ash litter is relatively high in nitrogen, it is expected that there will be important changes in nutrient and carbon cycling and subsequent rates of productivity and decomposition. Changes in hydrology and nutrient and carbon cycling will have cascading effects on the biological community which have been scarcely studied. Research to address these important gaps is currently underway and should lead to alternatives to mitigate the effects of EAB on black ash wetland forests and develop management options pre- and post-EAB invasion.

Softening behaviour of brown coal ashes. Influence of ash components and gas atmosphere

Energy Technology Data Exchange (ETDEWEB)

Hegermann, R; Huettinger, K J [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Chemische Technik

1990-03-01

The softening behaviour of brown coal ashes during gasification is important for three reasons: (1) Formation of large agglomerates, (2) inactivation of catalytically active ash components, (3) encapsulation of parts of the coal. The softening behaviour of the ashes was studied with a high temperature dilatometer at ambient pressure in various atmospheres (air, CO{sub 2}, Ar/H{sub 2}O, Ar, H{sub 2}/H{sub 2}O, H{sub 2}) using a push-rod with a conical tip. The heating rate was 5 Kmin{sup -1}, the final temperature 1000deg C, the residence time 1 h. (orig.).

Drycon dry ash conveyor: dry bottom ash handling system with reduced operating costs and improved plant efficiency

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

The Drycon dry bottom ash extraction system is designed to remove bottom ash beneath the furnace, cooling it without any need of water. Fresh air in countercurrent flow to the ash is used for the ash cooling. Data presented show how savings of time and costs can be achieved with this system and how a boiler efficiency can be increased using this technology. Considerable advantages in the reliability of operation with new improvements of the design are described. 7 figs.

Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

OpenAIRE

A Minjigmaa; Ts Zolzaya; E Bayanjargal; B Davaabal; J Temuujin

2014-01-01

  Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on th...

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

International Nuclear Information System (INIS)

Maneerung, Thawatchai; Kawi, Sibudjing; Wang, Chi-Hwa

2015-01-01

Highlights: • CaO catalyst was successfully developed from wood gasification bottom ash. • CaCO 3 in bottom ash can be converted to CaO catalyst by calcination. • CaO catalysts derived from bottom ash exhibited high activity towards transesterification. • CaO catalysts derived from bottom ash can be reutilized up to four times. - Abstract: The main aim of this research is to develop environmentally and economically benign heterogeneous catalysts for biodiesel production via transesterification of palm oil. For this propose, calcium oxide (CaO) catalyst has been developed from bottom ash waste arising from woody biomass gasification. Calcium carbonate was found to be the main component in bottom ash and can be transformed into the active CaO catalyst by simple calcination at 800 °C without any chemical treatment. The obtained CaO catalysts exhibit high biodiesel production activity, over 90% yield of methyl ester can be achieved at the optimized reaction condition. Experimental kinetic data fit well the pseudo-first order kinetic model. The activation energy (E a ) of the transesterification reaction was calculated to be 83.9 kJ mol −1 . Moreover, the CaO catalysts derived from woody biomass gasification bottom ash can be reutilized up to four times, offering the efficient and low-cost CaO catalysts which could make biodiesel production process more economic and environmental friendly

Effect of rice husk ash and fly ash on the compressive strength of high performance concrete

Science.gov (United States)

Van Lam, Tang; Bulgakov, Boris; Aleksandrova, Olga; Larsen, Oksana; Anh, Pham Ngoc

2018-03-01

The usage of industrial and agricultural wastes for building materials production plays an important role to improve the environment and economy by preserving nature materials and land resources, reducing land, water and air pollution as well as organizing and storing waste costs. This study mainly focuses on mathematical modeling dependence of the compressive strength of high performance concrete (HPC) at the ages of 3, 7 and 28 days on the amount of rice husk ash (RHA) and fly ash (FA), which are added to the concrete mixtures by using the Central composite rotatable design. The result of this study provides the second-order regression equation of objective function, the images of the surface expression and the corresponding contours of the objective function of the regression equation, as the optimal points of HPC compressive strength. These objective functions, which are the compressive strength values of HPC at the ages of 3, 7 and 28 days, depend on two input variables as: x1 (amount of RHA) and x2 (amount of FA). The Maple 13 program, solving the second-order regression equation, determines the optimum composition of the concrete mixture for obtaining high performance concrete and calculates the maximum value of the HPC compressive strength at the ages of 28 days. The results containMaxR28HPC = 76.716 MPa when RHA = 0.1251 and FA = 0.3119 by mass of Portland cement.

Project ash cultch: A report on optimal oyster cultch based on a prepared fly ash substratum

International Nuclear Information System (INIS)

Price, K.S.; Hansen, K.M.; Schlekat, C.E.

1991-01-01

Based on a three year study involving setting, growth, mortality, oyster condition, and metals accumulation, the evidence is extensive and convincing that stabilized coal ash is an acceptable oyster growing cultch (substratum). Oyster larvae are attracted to set on coal ash cultch at commercial fishery densities, tend to grow as well as on natural substrata (oyster shell), and are moderately more exposed to predators on the puck shaped ash materials as produced for this study. Oysters grown for one to two years on coal ash do not accumulate heavy metals and generally are in good health as measured by several biological condition indexes

Effects of Wood Ash on Soil Fungi

DEFF Research Database (Denmark)

Cruz Paredes, Carla

), copper (Cu) and nickel (Ni), is a major environmental concern. This work is part of the project ASHBACK (www.ashback.dk) which addresses the potentials and possible problems in re-distributing wood ash to the forest. The aim of this thesis was to determine the effects of biomass ash application...... in a Norway spruce forest where different amounts of wood ash were spread on the soil to study the effects on ectomycorrhizal (ECM) fungi, bioaccumulation of metals in sporocarps, and microbial communities. Laboratory microcosm experiments were run in parallel to the field studies, to compare the effects...... of wood ash with factorial additions of lime and Cd to disentangle the pH and Cd effects of wood ash amendments using community trait distributions. Barley yield, P content, and Cd content were not affected by biomass ashes. Some arbuscular mycorrhizal (AM) fungal species were reduced when biomass ashes...

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

The aim of the project 'Adaptation of Wood Ashes to Recycling' is to evaluate a new technique - roll pelleting - for making wood ash suitable for reuse as a fertiliser for woodland. The project is being carried out at the forest product companies AssiDomaen and Stora Enso. The main financier is the Swedish National Energy Administration. Other financiers are AssiDomaen, Stora Enso, The Thermal Engineering Research Institute and The Forestry Research Institute of Sweden. The project has involved the construction of a full-scale roll pelleter in a mobile container and its trial operation at two Swedish pulp and paper mills. The leaching properties of the ash products were studied with a laboratory method. In addition, the effects of ash fertilisation with these products are being studied in a four-year field trial. Effects on soil pH, nutrient supply, soil water chemistry and ground vegetation are being evaluated by The Forestry Research Institute of Sweden and will be reported separately in the year 2003. In a laboratory prestudy, the leaching properties of pellets from twelve different ash products made in a laboratory prototype machine were evaluated. The ash products were made from residues from the AssiDomaen Froevi mill and the Stora Enso Fors mill. Fly ash from Froevi was used alone and mixed with green liquor sludge and lime sludge respectively. Fly ash from Fors was also used alone and mixed with coating colour. The laboratory method used for the evaluation of leaching properties is the method developed by IVL The Swedish Environmental Research Institute Ltd. The results show that the progress of the leaching of roll pelleted ash is significantly slower than for the corresponding crushed product and a reference lime product. The speed of leaching, measured as acid neutralisation capacity, ANC, was significantly lower for the roll pelleted ash compared to self-hardened and crushed ash products. Because of the high content of calcium, lime has on the whole, a

The Photocatalytic Removal of Ortho Chlorophenol from Aqueous Solution Using Modified Fly Ash - Titanium Dioxide

Directory of Open Access Journals (Sweden)

Mohamad Malakootian

2016-05-01

Full Text Available The photocatalytic process is a useful method for the effective removal of phenolic compounds. Conducted in the spring‒summer 2013 at the Engineering Research Center for Environmental Health, Kerman University of Medical Sciences, this experimental study used a modified fly ash‒TiO2 mixture to enhance the photocatalytic removal efficiency of ortho-chlorophenol. Fly ash obatined from the Thermal Power Plant in Zarand, Kerman, was initially washed with sulfuric acid before being oxidized with potassium permanganate. The mixture of modified fly ash and TiO2 was then used for the removal of ortho-chlorophenol in the presence of UV light and the factors involved in the removal process were optimized. It was found that the ortho-chlorophenol removal efficiency recorded by the mixture of modified fly ash and TiO2 was higher than that by each of the modified fly ash or TiO2/UV alone. It was, further, observed that removal efficiency with a modified fly ash to TiO2 ratio of 3:1 rose to 98.8% under optimum conditions (i.e., pH: 2; contact time: 2 h; room temperature (29±2˚C, and a catalyst dose of 0.6 g. The ortho-chlorophenol removal efficiency in real wastewater from the Coal Wash Plant in Zarand was recorded at 88.4%. Based on the results obtained from simultaneous use of modified fly ash and TiO2, the proposed method may be recommended for industrial applications.

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

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.K.; Wall, T.F.; Gupta, R.P. [Cooperative Research Centre for Black Coal Utilisation, Newcastle, NSW (Australia); Creelman, R.A. [Creelman (R.A.) and Associates, Sydney, NSW (Australia)

1997-04-01

Ash deposition on furnace walls in PF (pulverized fuel) furnaces is called slagging when it occurs in the high temperature areas of furnaces directly exposed to flame radiation and fouling in other regions such as tubes in the convection section of the boiler. There are well documented shortcomings of certain approaches relating to their uncertainties as predictive tools for plant performance such as poor repeatability and re-producibility of ash fusion measurements. The nature of physical and chemical changes occurring during melting of coal ash has been investigated in the current study to provide an alternative procedure to the ash fusion test. Shrinkage measurements are frequently used in metallurgy and ceramic science to study the physical properties of materials at high temperatures. The output of this experiment provides three to four `peaks` (maximum rate of shrinkage with temperature) of different intensity and at different temperatures which are related to melting characteristics of the sample. It was concluded that shrinkage extents exceeding 50 percent indicated that the effect of the ash particle size is of secondary importance compared to ash chemistry in determining shrinkage levels, with fine particles giving rapid shrinkage events 10 degrees C lower in temperature. (author). 7 figs., refs.

Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

Energy Technology Data Exchange (ETDEWEB)

Visa, Maria, E-mail: maria.visa@unitbv.ro; Chelaru, Andreea-Maria, E-mail: andreea.chelaru1@yahoo.com

2014-06-01

Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO{sub 2}/Al{sub 2}O{sub 3} over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

International Nuclear Information System (INIS)

Visa, Maria; Chelaru, Andreea-Maria

2014-01-01

Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO 2 /Al 2 O 3 over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

Publication sites productive uses of combustion ash

Science.gov (United States)

Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

The influence of blast furnace slag, fly ash and silica fume on corrosion of reinforced concrete in marine environment

NARCIS (Netherlands)

Polder, R.B.

1996-01-01

Chloride penetration from sea water may cause corrosion of reinforcement in concrete structures. Adding reactive inorganic materials such as blast furnace slag, fly ash or silica fume to the cement matrix improves the resistance against chloride penetration as compared to Portland cement concrete. A

Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.

Directory of Open Access Journals (Sweden)

Karen van Eunen

Full Text Available Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH. The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.

Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: A study of archived basaltic to rhyolitic ash samples

Science.gov (United States)

Damby, David; Horwell, Claire J.; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

2017-01-01

BackgroundThe eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland’s volcanoes to Icelandic and Northern European populations. MethodsA physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. ResultsIcelandic ash can be of a respirable size (up to 11.3 vol.% < 4 μm), but the samples did not display physicochemical characteristics of pathogenic particulate in terms of composition or morphology. Ash particles were generally angular, being composed of fragmented glass and crystals. Few fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m2 g−1, which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO•), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after ‘refreshing’ sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m−2, with mafic samples releasing more iron

FALL3D: A computational model for transport and deposition of volcanic ash

Science.gov (United States)

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

2009-06-01

FALL3D is a 3-D time-dependent Eulerian model for the transport and deposition of volcanic ashes and lapilli. The model solves the advection-diffusion-sedimentation (ADS) equation on a structured terrain-following grid using a second-order finite differences (FD) explicit scheme. Different parameterizations for the eddy diffusivity tensor and for the particle terminal settling velocities can be used. The code, written in FORTRAN 90, is available in both serial and parallel versions for Windows and Unix/Linux/Mac X operating systems (OS). A series of pre- and post-process utility programs and OS-dependent scripts to launch them are also included in the FALL3D distribution package. Although the model has been designed to forecast volcanic ash concentration in the atmosphere and ash loading at ground, it can also be used to model the transport of any kind of airborne solid particles. The model inputs are meteorological data, topography, grain-size distribution, shape and density of particles, and mass rate of particle injected into the atmosphere. Optionally, FALL3D can be coupled with the output of the meteorological processor CALMET, a diagnostic model which generates 3-D time-dependent zero-divergence wind fields from mesoscale forecasts incorporating local terrain effects. The FALL3D model can be a tool for short-term ash deposition forecasting and for volcanic fallout hazard assessment. As an example, an application to the 22 July 1998 Etna eruption is also presented.

Release of microspherolites and metals extraction from energetical fly ashes by Bacillus isolates

Directory of Open Access Journals (Sweden)

Štyriaková Iveta

2000-09-01

they have a different resistance to the bacterial destruction. Metals (iron, titanium are comprised in an oxide form both in a non-combusted residue and allotrimorphic grains with amorphous aluminosilicate spherical particles.SEM enabled us to observe that the fresh fly-ash contains disseminated aluminosilicate spherical particles, with the size 1-70 µm that are released, probably together with metals, especially iron and titanium. The yielding of individual elements show a lower extraction of iron (3,3% and titanium (15,2% in the case of sample of 5 year - deposited fly-ash and a slightly higher yielding of iron (6,2% and titanium (29,1% in the case of sample of 20 year deposited fly-ash. A long-term deposition of energy fly-ash causes chemical and mineralogical changes as a result of weathering processes demonstrated by a lower extraction of metals from fly-ash.Although acids produced by Bacillus spp. were not measured in these experiments, in our previous experiments were detected several organic acids such as acetic, butyric, pyruvic, lactic, and formic acids after bioleaching of aluminosilicate samples.

Utilization of Hospital Waste Ash in Concrete

Directory of Open Access Journals (Sweden)

Shazim Ali Memon

2013-01-01

Full Text Available Hospital waste management is a huge problem in Pakistan. The annual production of medical waste produced from health care facilities, in Pakistan, is around 250,000 tons. This research paper is intended to evaluate the feasibility of using of hospital waste ash obtained from Pakistan Institute of Medical Sciences, Rawalpindi, Pakistan, as partial replacement of cement. The main variable in this research is the amount of hospital waste ash (2, 4, 6 and 8% by weight of cement while the amount of cementitious material, water to cementitious material ratio, fine and coarse aggregate content were kept constant. Test results substantiate that hospital waste ash can be used in concrete. XRD (X-Ray Diffraction of hospital waste ash showed that it is rich in calcite while scanning electron micrographs indicated that the particles of hospital waste ash have highly irregular shape. The slump value, density of fresh concrete and water absorption decreased with the increase in the quantity of hospital waste ash in the mix. At 3 days of testing, the compressive strength of mixes with hospital waste ash was higher than the control mix while at 7 and 28 days the CM (Control Mix showed higher strength than the hospital waste ash mixes except the mix containing 2% hospital waste ash by weight of cement.

Utilization of hospital waste ash in concrete

International Nuclear Information System (INIS)

Memon, S.; Sheikh, M.

2013-01-01

Hospital waste management is a huge problem in Pakistan. The annual production of medical waste produced from health care facilities, in Pakistan, is around 250,000 tons. This research paper is intended to evaluate the feasibility of using of hospital waste ash obtained from Pakistan Institute of Medical Sciences, Rawalpindi, Pakistan, as partial replacement of cement. The main variable in this research is the amount of hospital waste ash (2, 4, 6 and 8% by weight of cement) while the amount of cementitious material, water to cementitious material ratio, fine and coarse aggregate content were kept constant. Test results substantiate that hospital waste ash can be used in concrete. XRD (X-Ray Diffraction) of hospital waste ash showed that it is rich in calcite while scanning electron micrographs indicated that the particles of hospital waste ash have highly irregular shape. The slump value, density of fresh concrete and water absorption decreased with the increase in the quantity of hospital waste ash in the mix. At 3 days of testing, the compressive strength of mixes with hospital waste ash was higher than the control mix while at 7 and 28 days the CM (Control Mix) showed higher strength than the hospital waste ash mixes except the mix containing 2% hospital waste ash by weight of cement. (author)

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)