Fly Ash

Fire is one of the most severe environmental conditions that concrete structures might be subjected to, especially in closed conduct structures, such as tunnels. Concrete in general can withstand fire but its properties degrade when exposed to fire at high temperatures. The effect of heating duration, at a high temperature, on the performance of fly ash-based geopolymer concrete is presented. Cubes of low, medium and high strength grades of geopolymer concrete that had been cured for 28 days, were exposed to a fire flame at 1000 °C for 30, 60, 90, 120, 150 and 180 min. After the fire exposure, the cubes were cooled to the ambient temperature before further testing. A visual observation was performed on the cubes to detect any colour change, cracking and spalling. The losses of mass and residual compressive strength of the cubes were recorded. The results showed that as the heating duration increased from 30 to 90 min, the compressive strength of the cubes also increased. Contrarily, the compressive strength decreased as the heating duration increased beyond 90 min indicating that the extended heating duration induced the loss of free water and decomposition of aluminosilicate products in geopolymer concrete. The evaporation of water by virtue of the heating for the extended duration, at high temperature, led to a loss in the mass of concrete. The findings suggest that geopolymer concrete was able to sustain its structural integrity without any noticeable spalling and hence, it can be classified as a fire-resistant material.

Swelling mica exhibits unique characteristics for purification of drinking water contaminated by heavy metals and for selective removal of Sr2+ and Ba2+ ions from nuclear waste solution. As a new approach to recycle fly ash, conversion of fly ash to swelling mica has been attempted and ion-exchange properties of fly ash-derived swelling mica (referred to hereinafter as FA-swelling mica) were

Concrete in farm buildings is subjected to severe corrosion if manure is stored below slatted floors. Many chemicals associated with manure are identified as having a detrimental effect on concrete and the reinforcing steel embedded in the concrete. Of these, hydrogen sulfide is the most corrosive agent that leads to the rapid deterioration of concrete in barns. As well, manure has high concentrations of sulfates. In the present study, 48 concrete cylinders, 100 mm diameter and 100 mm high, were made with Portland cement, and various combinations of slag, fly ash and silica fume. Each has a reinforcing steel bar embedded in it. 24 cylinders are half immersed in sodium sulfate (20,000 ppm SO4 2- ) and also subjected to hydrogen sulfide gas (1,000 ppm H2S). The second set of 24 is subjected only to hydrogen sulfide gas. In each set, there are 8 different treatments. The specimens results indicate that after 16 cycles (each cycle is about five weeks long) of testing over 28 months, spe...

The reduction in the sources of natural sand and the requirement for reduction in the cost of concrete production has resulted in the increased need to identify substitute material to sand as fine aggregates in the production of concretes. Quarry dust, a by-product from the crushing process during quarrying activities is one of the materials being studied. This paper reports the experimental study undertaken to investigate some properties of quarry dust and discusses the suitability of those properties to enable quarry dust to be used as partial replacement material for sand in concrete. The properties of quarry dust that were determined are aggregate crushing value, flakiness index, pH value, soundness, specific gravity, absorption and fineness modulus. Besides, the 28 th day compressive strength of concrete specimens, in which partial replacement of river sand with quarry dust were practiced, is also reported for comparison purposes. Results obtained indicate that the incorporation of quarry dust into the concrete mix as partial replacement material to river sand resulted in lower 28 th day compressive strength. This can partly be attributed to the properties of the quarry dust which might contribute to the negative effects in the strength of the concrete. The results of the study also indicates that quarry dust can be utilised as partial replacement material to sand, in the presence of silica fume or fly ash, to produce concretes with fair ranges of compressive strength.

Waste foundry sand (WFS) and fly ash D-Optimal mixture design/response surface methodology/design of experiments Statistical optimization Geopolymer concrete (GPC) Compressive strength A B S T R A C T This work examines the partial replacement of fine aggregates with waste foundry sand (WFS) and fly ash, process by-products, to synthesize geopolymer concrete (GPC). D-optimal mixture design of experiments was adopted to guide the proportion of mixture constituents (fine aggregates, WFS, and fly ash) to obtain desired responses (high compressive strengths). The experimentally measured responses/compressive strengths were successfully fitted to Scheffe polynomial model to obtain cubic models which represent compressive strengths of solidified GPC at 7 th day curing time (CS 7) and at 28 th day curing time (CS 28). The models were statistically evaluated by the standard error of design estimation and experimentally verified by comparing their predicted responses to the independently performed experiments. The models were subjected to analysis of variance (ANOVA) and residuals (diagnostics) for statistical significance and validation, respectively. The established models, hence obtained, were used to assess the impacts of relative proportions of mixture constituents at CS 7 and CS 28. It was observed that, although the highest compressive strength requires a high proportion of fine aggregates, yet, some mixture compositions could be proposed for better utilization of waste materials. Finally, the optimization was performed to maximize the usage of WFS and fly ash. A recipe was identified which yielded 18.9 N/mm² CS 7 and 22.3 N/mm² CS 28 by mere 32 wt. % contribution of fine aggregates in a (fine aggregates + WFS + fly ash) mixture. This study can be helpful in designing experiments and optimizing the utilization of similar waste materials into useful products.

In our recent study, BABA has been tested to manage Meloidogyne incognita under stress conditions due to fly ash. The reduction in the growth of pathogen under abiotic stress is being intensified by DL-β-amino butyric acid (BABA). The combination of abiotic and biotic stress can have a positive effect on the yield of plants by reducing the sensitivity to biotic tension and limiting the crop yield and more priority has been given on the surface of the research table now a days. Therefore this study was carried out observe the effect in combination of Fly ash and BABA in resistance to Root knot nematodes. Results indicate that 30% fly ash in combination with BABA (125 μg/ml) undoubtedly reduced the gall Index by 50% when compared with the control. The interesting thing is that the lower dose of BABA when combined with the abiotic stress was similar to the high dose of BABA efficacy (250 μg / ml).

This paper presents the results of an investigation on the combined effect of particle size and chemical composition on the colour of fly ash -a property that determines whether fly ash polymer composites can be engineered to have very light appearance satisfying the need for a wide range of commodity applications, particularly in the building material and computer housing industry. Four fly ash samples were collected from Tarong power plant Queensland, Australia, namely fly ash from first hopper (T59), classified fly ash from first hopper (T60), grinded and then classified fly ash from first hopper (T63) and fly ash from fourth hopper (T64). It was found that the particle size of T64 is smaller but still in the same order as T63. Colour measurement and chemical composition analysis of the different FA samples showed that there is a correlation between the particle size, chemical composition and colour of the fly ash. This information could be effectively used in fly ash recycling industry.

This paper reported mercury speciation and emissions from five coal-fired power stations in China. The standard Ontario Hydro Method (OHM) was used into the flue gas mercury sampling before and after fabric filter (FF)/electrostatic precipitator (ESP) locations in these coal-fired power stations, and then various mercury speciation such as Hg 0 , Hg 2+ and Hg P in flue gas, was analyzed by using EPA method. The solid samples such as coal, bottom ash and ESP ash, were analyzed by DMA 80 based on EPA Method 7473. Through analysis the mercury speciation varied greatly when flue gas went through FF/ESP. Of the total mercury in flue gas, the concentration of Hg 2+ is in the range of 0.11-14.76 μg/N m 3 before FF/ESP and 0.02-21.20 μg/N m 3 after FF/ESP; the concentration of Hg 0 ranges in 1.18-33.63 μg/N m 3 before FF/ESP and 0.77-13.57 μg/N m 3 after FF/ESP, and that of Hg P is in the scope of 0-12.11 μg/N m 3 before FF/ESP and 0-0.54 μg/N m 3 after FF/ESP. The proportion of Hg 2+ ranges from 4.87%-50.93% before FF/ESP and 2.02%-75.55% after FF/ESP, while that of Hg 0 is between 13.81% -94.79% before FF/ESP and 15.69%-98% after FF/ESP, with that of Hg P is in the range of 0%-45.13% before FF/ESP and 0%-11.03% after FF/ESP. The mercury in flue gas mainly existed in the forms of Hg 0 and Hg 2+ . The concentrations of chlorine and sulfur in coal and flue gas influence the species of Hg that are formed in the flue gas entering air pollution control devices. The concentrations of chlorine, sulfur and mercury in coal and the compositions of fly ash had significant effects on mercury emissions.

In order to address environmental effects associated with Portland cement, there is need to use other binders to make concrete. An effort in this regard is the development of geopolymer concrete, synthesized from the materials of geological origin or by product materials such as fly ash, which are rich in silicon and aluminum. This paper presents results of an experimental study on the strength and absorption characteristics of geopolymer concrete.

The capability of 14 zeolites synthesized from different fly ashes (ZFAs) to sequestrate Cr(III) from aqueous solutions was investigated in a batch mode. The influence of pH on the sorption of Cr(III) was examined. ZFAs had a much greater ability than fly ash to remove Cr(III), due to the high cation exchange capacity (CEC) and the high acid neutralizing capacity (ANC) of ZFAs. The mechanism of Cr(III) removal by ZFAs involved ion exchange and precipitation. A high-calcium content in both the fly ashes and ZFAs resulted in a high ANC value and, as a result, a high immobilization capacity for Cr(III). The pH strongly influenced Cr(III) removal by ZFAs. Inside the solubility range, removal of chromium increased with increasing pH. Hydroxysodalite made from a high-calcium fly ash had a higher sorptive capacity for Cr(III) than the NaP1 zeolite from medium-and low-calcium fly ashes. On the other hand, at pH values above the solubility range, the efficiency of chromium removal by the ZFAs approached 100% due to the precipitation of Cr(OH) 3 on the sorbent surfaces. It is concluded that ZFAs and high-calcium fly ashes may be promising materials for the purification of Cr(III) from water/wastewater.

The Indonesian Government's decision to remove Fly Ash and Bottom Ash (FABA) coal waste from the hazardous and toxic materials (B3) list has generated pros and cons in various circles. The waste that comes from burning coal is known to have harmful side effects for health and damage to the environment and the living biota in it. However, according to the test results of the Indonesian Ministry of Environment, FABA waste does not meet the characteristics of B3, and it has high economic benefits in several countries that have succeeded in managing this type of waste, such as China, Japan, the United States and others. If the Government can create good regulations, this waste will be a vast potential, both environmentally and economically. Learning from European countries that have succeeded in managing this waste by forming a particular association that deals with coal waste, Indonesia needs to apply international standards so that this potential does not impact environmental health through related international cooperation. Using the literature study method, this research will be qualitative, and environmental theory and international cooperation will describe and analyze Indonesia's opportunities in accelerating the use of FABA-type coal waste through international cooperation. The target achievement of this research is a policy recommendation for the Government on issues related to the handling of coal waste types of FABA.

The bagasse fly ash, an industrial solid waste of sugar industry, was used for the removal of cadmium and nickel from wastewater. As much as 90% removal of cadmium and nickel is possible in about 60 and 80 min, respectively, under the batch test conditions. Effect of various operating ...

Fly Ash (FA) from South African power stations was successfully used to treat Acid Mine Drainage (AMD) and the insoluble residual solids that were obtained as a result of the reaction between FA and AMD proved suitable as a backfill material for mine stabilization. Particle Size Distribution (PSD) of FA varies from time to time depending on the coal burning conditions in the power station. Such variability in PSD of FA could influence its capability to neutralize AMD as well as the flow behaviour of residual solids that have to be transported hydraulically to the backfill site. The objective of this paper is to study the influence of variability of PSD on the above mentioned properties. The FA from Arnot power station in South Africa was used for this study. PSD analysis showed that the FA particle size distribution was <25 m (38%), 25-75 m (42%) and 75-150 m (14%). The % of fine and coarse particles (in the context of this study) could influence the neutralization capacity of FA...

The present paper deals with the static weight loss corrosion studies of Aluminium 2024 metal matrix composites reinforced with fly ash particulates in comparison with matrix alloy using different concentrations of potassium chloride solution. Matrix alloy used in Aluminium 2024 and there inforcement used was fly ash particulates. Composites are prepared by liquid melt metallurgy technique method. Fly ash particulates are reinforced by 2,4,6 percent by weight under dry conditions. Specimens are prepared according to ASTM standards. Both metal matrix composites and corresponding base alloys were subjected to identical test conditions to understand the influence of there inforcement on alloy with respect to corrosion behaviour and effective corrosion control Composites show less prone to corrosion and pit formation than the matrix alloy, which may be due to chemically inertflyash particles present in the metal matrix composites. On the other hand the test also reveals that corrosion resistance of both alloy composites increase with increase in exposure time in all concentrations of potassium chloride solution, which may be due to formation of a passive layer on the surfaces of matrix alloy and composites. Corrosion of metal matrix can be effectively controlled by converting the min to composites by the addition of inertand ceramic materials like flyash particulates. If any automobile parts like bearing are @ IJTSRD |

Large amounts of fly ash (FA) and limestone powder (LP) wastes are accumulating in countries all over the world. Most of these wastes are abandoned and cause certain serious environmental problems and health hazards. In this study, LP waste and class-C FA were used to produce a composite material without the addition of portland cement. LP was mixed with the FA at levels of 10, 20 and 30% by volume in the samples. LP and FA were mixed, wetted and compressed under high pressure in a steel mould. The compressive and flexural strengths were measured, and ultrasonic pulse velocity tests were performed on samples at ages of 7, 28 and 90 days. Density, water absorption and thermal conductivity values were also determined for the samples aged for 28 days. Preliminary results obtained from the tests indicate that masonry composites can be produced using LP, FA and water.

The morphology, mineralogy, and magnetic properties of technogenic magnetic particles (TMPs) were analysed in four kinds of industrial dust produced during high temperature technological processes of different branches of industry (lignite and hard coal burning, cement production, coke production). The study was carried out by means of magnetic susceptibility measurement, energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), X-ray diffraction, Mössbauer spectroscopy, and thermomagnetic analysis. To assess the total content of the magnetic fraction in bulk dust samples, mass specific magnetic susceptibility (c) was measured and then a physical separation of magnetic particles (mostly of technogenic origin) was conducted. The dusts revealed high diversity of the c value, which was dependent on the magnetic particles' concentration and mineralogical composition. Significant differences in the magnetic mineralogy of dusts coming from different branches of industry were observed. In fly ashes from coal combustion, spherical forms (typical ferromagnetic spherules) of magnetite, magnesioferrite, and maghemite were mostly observed. In dusts after lignite combustion a higher content of antiferromagnetic hematite and maghemite was observed due to the lower temperature of lignite combustion. In cement dusts a large variety of iron minerals were observed including magnetite, maghemite, hematite, ferrites, and goethite. The characteristic mineral forms for cement dusts were Ca-ferrites and co-occurrence of calcite, anhydrite, gypsum, and bassanite with a magnetic mineral fraction. The magnetic fraction produced by the coke industry was mostly in the form of tightly compacted aggregates with well-formed crystal structures where ferromagnetic pyrrhotite was characteristic feature. The TMPs could be distinctive for pollution source identification and serve as a tracer of dust origin and (if found in topsoil) identification of soil pollution sources.

Fly ashes do not have the same properties for different size fractions. It can be accepted that the effect of a fly ash on mortar strength is a combined effect of its size fractions. Therefore, it was concluded that by separating the size fractions and replacing cement with them, the combined bulk effect of a fly ash on strength can be better analysed. In this study, different size fractions of fly ash were used to replace cement partially in standard compressive strength mortars. We attempted to interpret the strength of Portland cement-fly ash mortars in terms of the chemical, minerological, morphological, and physical properties of different fly ash size fractions used. Strengths of the mortars were compared at 2, 7, 28, and 90 days. Also strength of mortars with all-in ash (original ash containing all the fractions) were estimated by using strength of mortars with size fractions and the suitability of this estimation was discussed.

Coal fly ash (CFA) is a waste product produced from the electrical power plant and hazardous towards the environment. However, the high composition of silica and alumina in the CFA makes it useful as raw materials in the zeolite synthesis. However, the presence of silica in the form of quartz in the CFA does not facilitate the transformation of CFA to zeolite at 100oC and autogeneous pressure. In this study, CFA was converted to zeolites in various NaOH concentrations by microwave heating at various heating time. All synthesized product were characterized by X-ray diffraction(XRD), and gravimetric analysis. XRD has shown that quite pure sodalite in nanosize has been formed as early as 15 minutes and increase with time. Prolong heating up to 45 minutes has reduced the content of quartz to ca 20%. Gravimetric analysis performed on the liquor of the reaction showed that the dissolved silica decrease with increase of heating time indicating that most of the dissolved quartz is used up to form sodalite framework. Hence, quartz of CFA did help in enhancing the crystallinity of the formed sodalite after prolong heating.

In many countries throughout the world, fly and bottom ashes originating from coal-fired thermal power plants are declared as wastes requiring special care during reuse and disposal. In this regard, a number of toxicity tests have been developed to assess the metal leaching potential of ash residues. In this study, fly ash samples obtained from the Ç atalagzı thermal power plant, located on the northwestern coast of Turkey, were subjected to toxicity tests such as the extraction (EP) and toxicity characteristic leaching (TCLP) procedures of the U.S. Environmental Protection Agency (U.S. EPA), and the so-called Method A extraction procedure of the American Society of Testing and Materials (ASTM). The results observed for the extracts were compared with each other and the selected tests were evaluated in terms of their use in representing leaching under natural field conditions.

The potential problems and their consequences due to fly ash disposal have been well studied around the world. Ash pond is a common available disposal facility for thermal power plants. The pond ash is subjected to weathering and the ions present in ash migrate to the soil ...

In this paper, a comprehensive computational fluid dynamics (CFD) modelling study was undertaken by integrating the combustion of pulverized dry lignite in several combustion environments. Four different cases were investigated: an air-fired and three different oxy-fuel combustion environments (25 vol.% O 2 concentration (OF25), 27 vol.% O 2 concentration (OF27), and 29 vol.% O 2 concentration (OF29) were considered. The chemical reactions (devolatilization and char burnout), convective and radiative heat transfer, fluid and particle flow fields (homogenous and heterogenous processes), and turbulent models were employed in 3-D hybrid unstructured grid CFD simulations. The available experimental results from a lab-scale 100 KW firing lignite unit (Chalmer's furnace) were selected for the validation of these simulations. The aerodynamic effect of primary and secondary registers of the burner was included through swirl at the burner inlet in order to achieve the flame stability inside the furnace. Validation and comparison of all the combustion cases with the experimental data were made by using the temperature distribution profiles and species concentration (O 2 , CO 2 , and H 2 O) profiles at the most intense combustion locations of the furnace. The overall visualization of the flame temperature distributions and oxygen concentrations were presented in the upper part of the furnace. The numerical results showed that the flame temperature distributions and O 2 consumptions of the OF25 case were approximately similar to the reference combustion case. In contrast, in the OF27 and OF29 combustion cases, the flame temperatures were higher and more confined in the closest region of the burner exit plane. This was a result of the quick consumption of oxygen that led to improve the ignition conditions in the latter combustion cases. Therefore, it is concluded that the resident time, stoichiometry, and recycled flue gas rates are relevant parameters to optimize the design of oxy-fuel furnaces. The findings showed reasonable agreement with the qualitative and quantitative measurements of temperature distribution profiles and species concentration profiles at the most intense combustion locations inside the furnace. These numerical results can provide useful information towards future modelling of the behaviour of pulverized brown coal in a large-scale oxy-fuel furnace/boiler in order to optimize the burner's and combustor's design.

Fly ash is generated in large measures, especially by thermal power plants. A great batch of inquiry has been channeled out for efficient utilization of fly ash in the structure industry. Use of fly ash in manufacturing brick is one such thing which is being studied by many research scholars and engineers. The aim of the present study is to investigate the durability and water absorption features of fly ash bricks made up with different percentage of lime (L), local soil (S) and fly ash (FA). The experiments were conducted by both Pressure molded fly ash bricks. It was found that none of the L-S-FA bricks satisfy all the demands of standard codes. While some of the bricks satisfy the provisions in respect of intensity level only the L-S-FA (40-0- 60) bricks satisfy the demand of Indian Standard Code in respect of intensity as easily as water absorption features.

Self- Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without bleeding or segregation. In recent years, self-compacting concrete has been gaining wide range of application for placement in congested reinforced concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The use of additive materials such as industrial wastes as mineral admixtures can ensure the required concrete properties. The initial experimental study aims at producing and evaluating SCC for ternary blends incorporating fly ash, GGBS, sugarcane bagasse ash and alccofine as partial replacement of cement. Five number of SCC mixes were investigated in this study. The self-compacting mixes have cement replacement with different percentages of mineral admixtur...

In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 • C for 8 h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm −1 shifts to lower wave number around 1007 cm −1 , and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals.

It has been proposed that oxidant stress of cells in the lung is one of the underlying mechanisms of particulate pollution-induced exacerbation of lung disease. Individuals who are considered most sensitive to particulate pollution are those with pre-existing airways inflammation, such as chronic obstructive pulmonary disease (COPD), lung infection or asthma. These diseases are characterized by a presence of inflammatory cells in the airways including neutrophils (PMN), eosinophils and monocytes (Mo), and increased numbers of alveolar macrophages (AM). These cells have a high capacity for production of oxygen radicals, as compared to other cell types of the lung. To assess the oxidative response of these various cell types to pollution particles of various sources, luminol-dependent chemiluminescence was employed. Particles including transition metal-rich residual oil fly ashes (ROFAs), coal fly ashes, diesel, SiO 2 , TiO 2 and fugitive dusts were co-cultured with AM, Mo and PMN in a dose range of 10-100 mg/2Â10 5 cells and chemiluminescence determined following a 20-min interaction. A strong oxidant response of AM was restricted to oil fly ashes, while the PMN were most reactive to the dusts containing aluminium silicate. In general, the Mo response was less vigorous, but overlapped both AM-and PMN-stimulating dusts. However, in response to SiO 2 and volcanic ash the Mo chemiluminescence exceeded that of the other cell types. Oxygen radicals generated in response to ROFA by the AM were likely to be dependent on mitochondrial processes, while the response in PMN involved the membrane NADPH oxidase complex, as determined by targeting inhibitors. The response of AM to SiO 2 of various sizes and TiO 2 in the fine size range obtained from different commercial sources, was highly variable, implying that composition rather than size was responsible for the oxidant response. A strong chemiluminescence response was not consistently associated with cytotoxicity in the responsive cell. Taken together, these results suggest that oxidant activation by various sources of particulate matter is cell specific. Therefore, the inflamed lung is likely to be more susceptible to harm of ambient air particulates because of the oxidant stress posed by a broader range of particles.

Sustainable use of solid residues and carbon dioxide, the two largest and most important waste products from thermal processes, is an urgent issue both for the industry involved and society as a whole, considering the financial and environmental repercussions of their production. This Knowledge Platform focuses on three types of waste-to-product valorisation: production of a carbon sink, construction materials, or sorbents. Thermal processes are widely applied in metals and cement production, waste incineration, etc. They produce major amounts of solid waste materials, such as slag and fly ash, and generate a vast amount of carbon dioxide. Mineral carbon sequestration in alkaline waste materials is a feasible solution because of high reactivity, on-site production, waste stabilization and low cost. Turning waste into construction materials is another route for transforming low-cost input materials into potentially high-value products. The production of a sorbent for wastewater and flue gas treatment is another promising industrial option for in-house treatment of waste streams. A successful approach requires a broad consortium with relevant expertise for the scientific investigation, but which at the same time can be easily tailored to a particular valorisation option that emerges. The Platform aims at this dual objective by bringing together all parties and by focusing on the challenging aim of valorising thermal process wastes into high-value products by intensified processes and with clear prospects on the economic and legislative feasibility, ecological benefits and societal relevance.

Cementitious materials derived from coal combustion by-products have been investigated by means of X-ray diffraction (XRD) and S and Ca K-edge X-ray absorption fine structure (XAFS) spectroscopy. The XRD analysis revealed that these materials are a complex mixture of a small amount of quartz [SiO 2 ] and three calcium-bearing compounds: hannebachite [CaSO 3 Á1/2H 2 O], gypsum [CaSO 4 Á2H 2 O] and ettringite [(Ca 6 (Al(OH) 6 ) 2 (SO 4 ) 3 Á26H 2 O)]. Analysis of the S XAFS data focused on deconvolution of the X-ray absorption near-edge structure (XANES) regions of the spectra. This analysis established that sulfate and sulfite are the two major sulfur forms, with a minor thiophenic component contained in unburned carbon in the fly ash. Increasing sulfate and decreasing sulfite correlated well with increasing gypsum and ettringite and decreasing hannebachite content in the samples. Different calcium compounds were identified primarily through simple comparison of the Ca K-edge XANES and radial structure functions (RSFs) of the cementitious samples with those of reference compounds. Because of the complex coordination chemistry of calcium in these materials, it was difficult to obtain detailed local atomic environment information around calcium beyond the first Ca)O peak. Analysis of the extended X-ray absorption fine structure (EXAFS) and the RSF gave average Ca)O distances in the range 2.44 -2.5 Å , with each calcium atom surrounded roughly by eight oxygen atoms. In certain samples, the average Ca)O distances were close to that in ettringite (2.51 Å ), suggesting that these samples have higher ettringite content. The results of S and Ca K-edges XAFS and the XRD data were in reasonable agreement. D

Our objective was to study mature grains of crops grown on various areas of power plant ash and bottom slag deposits. It was found that good grain quality with the application of usual agricultural techniques and intensified fertilization on various parts of ash and bottom slag deposits may be achieved with: autumn rye (Secale cereule L.), alfalfa (Medicngo sativu L.), barley (Hordeum sativum Jessen) and, to a lesser extent, winter raps (Brassica napus L.).

Inoculating legumes with commercial rhizobial inoculants is a common agriculture practice. Generally, inoculants are sold in liquid or in solid forms (mixed with carrier). The production of inoculants involves a step in which a high number of cells are produced, followed by the product formulation. This process is largely governed by the cost related to the medium used for rhizobial growth and by the availability of a carrier source (peat) for production of solid inoculant. Some industrial and agricultural by-products (e.g. cheese whey, malt sprouts) contain growth factors such as nitrogen and carbon, which can support growth of rhizobia. Other agro-industrial wastes (e.g. plant compost, Wltermud, Xy-ash) can be used as a carrier for rhizobial inoculant. More recently, wastewater sludge, a worldwide recyclable waste, has shown good potential for inoculant production as a growth medium and as a carrier (dehydrated sludge). Sludge usually contains nutrient elements at concentrations suYcient to sustain rhizobial growth and heavy metals are usually below the recommended level. In some cases, growth conditions can be optimized by a sludge pre-treatment or by the addition of nutrients. Inoculants produced in wastewater sludge are eYcient for nodulation and nitrogen Wxation with legumes as compared to standard inoculants. This new approach described in this review oVers a safe environmental alternative for both waste treatment/disposal and inoculant production.

The synthesis of zeolites from three samples of fly ash was carried out through a low-temperature (25-60°C) hydrothermal process with a NaOH pre-fusion treatment preceded by sonication. The results were compared with those of conventional hydrothermal syntheses. XRD and SEM investigations demonstrate that the application of ultrasonic treatment facilitates the formation of zeolites at a lower-temperature (25°C) than syntheses not preceded by sonication. No significant difference in type, temperature of crystallization, or amount of zeolites synthesized was noted between the three different samples of fly ash, implying that the chemical composition of fly ash had little influence on the zeolite product within the compositional range of these fly ash precursors. Although there appears to be a correlation between the SiO 2 /Al 2 O 3 ratio of the fly ash and the temperature of zeolite formation by conventional synthesis, no correlation was apparent when ultrasonic pre-treatment was used at low-temperatures.

Significant economic and environmental problems coming from the disposal of coal ash have led to the implementation of various alternative uses, in which combustion residues are considered as value-added products. In Greece, a large quantity of fly-ash is the inevitable by-product of Greek brown coal burning, due to its high ash content. In this paper, the main characteristics of fly-ash from Greek coal-fired boilers are presented in relation to its exploitation potential. Both fuel and fly-ash samples were collected and analysed 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. The ashes from the Greek brown coal are classified in type C, e.g. into class with high proportion of CaO, due to the fact that compounds of sulphur -calcium -aluminates are predominant. The total annual fly-ash production for the last two years was about 10x10 6 tons, most of which are produced in Ptolemais, Northern Greece. 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 1kBq kg -1 of 226 Ra. 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 utilization strategy should be developed, since low quantities of the total produced fly-ash is currently further utilized.

A pure 4A/X (60/40) zeolite product was synthesized from silica extracts of the Meirama fly ash in northwestern Spain. A high cation-exchange capacity (4.7 meq/g) was obtained for the zeolitic material. The potential application of this coal fly ash conversion product for decontamination of high heavy metal waters was evaluated using three high heavy metal waters from acid mine drainage around the pyrite Huelva belt. The results were compared with those obtained with an equivalent pure commercial synthetic zeolite. A considerable reduction in the heavy metal content was attained (Zn from 174 to <0.1 mg/L, Cu from 36 to 0.1 mg/L, Fe from 444 to 0.8 mg/L, Mn from 74 to <0.1 mg/L, Pb from 1.5 to <0.1 mg/L, and Cd from 0.4 to <0.1 mg/L), even in high Ca and Fe waters using zeolite doses from 5 to 30 mg/L. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concentration in the treated waters. Leachable hazardous elements from coal fly ash, such as Mo, B, As, V, and Cr, were not fixed in the synthesis of pure zeolites from the silica extracts. Consequently, they did not restrict the potential applications of this material as an ion exchanger, unlike the zeolitic material obtained from fly ash by direct alkaline conversion.

The demand of using local fly ash is growing rapidly in Indonesian cement industries. The quality of fly ash plays an important role to ensure since the quality of coal used is not uniform. Basically, good and fewer qualities of coal are mixed together in the field. Twelve representative samples of fly ash produced by five Indonesian power plants were collected from site and cement industries. All samples are class F fly ashes with good pozzolanic characteristics according to the standard. The samples were examined for their physical, mechanical and chemical properties with compression test. Mortar samples were made from each fly ash sample according to ASTM C 311. Their strength activity was examined at 7 and 28 days. The results showed that both physical and chemical properties of fly ash influenced the mechanical properties of mortars containing fly ash.

This study examines an attempt to produce self-compacting concrete (SCC) containing fly ash (FA), ground granulated blast furnace slag (S) and both (FA+S). The effects of these materials on the rheological properties of the SCC mixes were studied experimentally. The study began with three groups of SCCs, each with 25% water binder (w/b) and 550 kg/m3 total binder content. Instead of superplasticizers (SP), the chemical admixtures were lignosulphonates (LS), which replaced Portland cement (PC) at levels by weight of 10%, 20%, 30% 40%, 50%, and 60%. The fresh properties of the mixtures were examined experimentally for slump flow diameter, T50 time, V-funnel time, and L-box height ratio. In the mixtures with FA alone, a continuous decrease was observed in compressive strength. Increases in strength ended at 40% in the case of FA alone, and 30% for both the S and FA+S mixes. Statistical analysis was carried out to assess the effect of  experimentally substituted materials FA and S, with results showing
that S had a greater influence than FA on T50 time, V-funnel, L-box height ratio, and compressive strength, while FA had more effect than S on the slump flow diameter test.

Electronic waste is an emerging issue posing serious pollution problems to the human and the environment. The Disposal of electronic waste in an environment is considered to be a big problem due to its very low biodegradability and presence in large quantities. To rectify this environmental problem of disposing the E-waste, reuse of E-waste in concrete industry is considered as the most feasible application. This study focuses on the possibility of re-using E-waste that is now produced in large quantities in the formulation of concrete as a partial replacement of coarse aggregate along with the substitution of cement by fly ash. The work was conducted on M25 grade mix. Various cube specimens were casted with 5% replacement of coarse aggregate by e waste with fly ash ranging from 0-30% by weight of cement. Compressive strength test was conducted on the specimens after 7, 14 and 28 days of curing and the strength was recorded and compared with the strength of standard mix. The-E-waste is suitable to replace the coarse aggregate but not suitable as fine aggregate.

Главной целью данной работы является выявление влияния сдвига «сомбреро» от оси на показатель эффективности установки. Эта работа важна для реализации промышленной модели инерционно-вакуумного золоуловителя. Лучшая эффективность достигается при корректных размерах, пропорциях и отношениях одних элементов к другим, что очень сложно спроектировать в жизни. Ниже просчитаны различные варианты для проверки выявления отклонения эффективности улавливания от первичных результатов при вибрациях «сомбреро» из-за больших расходов потока уходящих газов. Разработка аппарата ИВЗ выполняется по заданию фонда «Энергия без границ».

Ice cores from the relatively low-lying ice caps in Svalbard have not been widely exploited in climatic and environmental studies due to uncertainties about the effect of melt water percolation. However, results from two recent Svalbard ice cores, at Lomonosovfonna (1250 m asl) and Austfonna (750 m asl), have shown that with careful site selection, high-resolution sampling and multiple chemical analyses, it is possible to recover ice cores with partly preserved annual signals. These cores are estimated to cover at least the past 600 years and have been dated using a combination of known reference horizons and glacial modeling. The d 18 O data from both Lomonosovfonna and Austfonna ice cores suggest that the 20th century was the warmest during the past 600 years. A comparison of the ice core and sea ice records from this period suggests that sea ice extent and Austfonna d 18 O are linked over the past 400 years. This may reflect the position of the storm tracks and their direct influence on the relatively low altitude Austfonna. Lomonosovfonna may be less sensitive to such changes and primarily record atmospheric changes due to its higher elevation. The anthropogenic influence on Svalbard environment is illustrated by increased levels of non-sea-salt sulphate, nitrate, acidity, fly-ash and organic contaminants particularly during the second half of 1900s. Decreased concentrations of some components in recent decades most likely reflect emission and use restrictions. However, some current-use organic pesticide compounds show growing concentrations in near surface layers.

This work aims to develop a new mineral porous tubular membrane based on mineral coal fly ash. Finely ground mineral coal powder was calcinated at 700°C for about 3 h. The elaboration of the mesoporous layer was performed by the slip casting method using a suspension made of the mixture of fly ash powder, water and PVA. The obtained membrane was submitted to a thermal treatment which consists in drying at room temperature for 24 h then a sintering at 800°C. SEM photographs indicated that the membrane surface was homogeneous and did not present any macro defects (cracks, etc.). The average pore diameter of the active layer was 0.25 lm and the thickness was around 20 lm. The membrane permeability was 475 l/h m 2 bar.

The respirable fraction of ash from the 1982 eruptions of Galunggung volcano, West Java, contains quartz and cristobalite in lesser quantities than Mount St Helens samples. Small amounts of these fibrogenic minerals may be characteristic of ash from andesitic, dacitic or some basaltic volcanoes. Inhalation of volcanic ash can precipitate respiratory distress, and prolonged exposure may induce fibrogenic pulmonary change. Ambient air monitoring in regions subjected to ashfall is essential to elucidate the respiratory hazard and provide a basis for epidemiological studies.