The Experts below are selected from a list of 21126 Experts worldwide ranked by ideXlab platform
Christof Lanzerstorfer - One of the best experts on this subject based on the ideXlab platform.
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investigation of dust resistivity for a fractioned biomass fly Ash Sample during poor combustion conditions with regard to electrostatic precipitation
Fuel, 2018Co-Authors: Dominik Steiner, Christof LanzerstorferAbstract:Abstract It is well known that dust resistivity and particle size play a major role in electrostatic precipitation processes. The electrostatic precipitator design also has to be adapted for carbon rich fly Ashes such as those found in heavy fuel oil combustion plants. In this work, an Ash Sample from an electrostatic precipitator downstream an industrial biomass boiler operated under poor combustion conditions was air classified into 5 particle size fractions. Those fractions were then analyzed regarding chemical composition, loss on ignition, particle size distribution and dust resistivity. Furthermore scanning electron as well as optical microscope images were taken to investigate particle structure and shape. Diverse types of particles were found in the different fractions, varying from unburned coal particles to inorganic sand-like particles. It was also found that chemical composition as well as resistivity varied significantly with different size fractions. During resistivity measurements, fluctuating voltage and current values were recognized, similar to what can be seen during the back-corona phenomenon, but found at medium resistivity values. Furthermore, suggestions for an electrostatic precipitator design will be given based on findings in this study.
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air classification potential treatment method for optimized recycling or utilization of fine grained air pollution control residues obtained from dry off gas cleaning high temperature processing systems
Waste Management & Research, 2015Co-Authors: Christof LanzerstorferAbstract:In the dust collected from the off-gas of high-temperature processes, usually components that are volatile at the process temperature are enriched. In the recycling of the dust, the concentration of these volatile components is frequently limited to avoid operation problems. Also, for external utilization the concentration of such volatile components, especially heavy metals, is often restricted. The concentration of the volatile components is usually higher in the fine fractions of the collected dust. Therefore, air classification is a potential treatment method to deplete the coarse material from these volatile components by splitting off a fines fraction with an increased concentration of those volatile components. In this work, the procedure of a sequential classification using a laboratory air classifier and the calculations required for the evaluation of air classification for a certain application were demonstrated by taking the example of a fly Ash Sample from a biomass combustion plant. In the in...
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investigation of the contamination of a fly Ash Sample during Sample preparation by air classification
International Journal of Environmental Science and Technology, 2015Co-Authors: Christof LanzerstorferAbstract:Information on the size dependence of the concentration of pollutants in fine-grained residues is required for the design of classification processes for their processing. For such an analysis, the Samples have to be classified prior to chemical analysis. Depending on the particle size range of the residue, a classification method has to be selected. For very fine material, air classification is a suitable method. In this work, the results of the classification of fly Ash from a biomass combustion plant with an air classifier are discussed with respect to the observed Sample contamination. The chemical analysis of the produced size classes for heavy metals yielded unexpected results. For most heavy metals, the mass balance resulted in a recovery rate of about 100 %; however, for Cr and Ni, the recovery rate was way above 100 %. A more detailed analysis of the data revealed that the ratio of the excess of Cr to Ni in the fly Ash was nearly the same as the ratio of Cr to Ni in the material of parts of the classifier. Therefore, erosion of some material from the classifier can be assumed to have caused the contamination of the Sample. For the classification of Samples, which have to be analysed for Cr and Ni, a classifier has to be used which is made of a material other than stainless steel.
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model based prediction of required cut size diameter for fractionation of fly Ash from a grate fired wood chip incineration plant
Fuel Processing Technology, 2011Co-Authors: Christof LanzerstorferAbstract:Utilization of biomass Ash as a soil improvement material is limited by the admissible input of heavy metals. It is well known that heavy metal concentrations are increased in fine Ash fractions. In this study, two models are investigated to describe the distribution of various heavy metals in different size fractions of fly Ash from a grate-fired biomass incineration plant incinerating wood chips. The second model assuming a dependence of the heavy metal concentration from the reciprocal particle diameter to the power of the variable N correlated well with measured concentrations. This model was then used in the calculation of the required cut size of a classifier for the production of a coarse fraction with heavy metal concentrations below limits from a fly Ash Sample exceeding the Austrian limits for a soil improvement material. The predicted concentrations of the critical heavy metals Cd and Pb and the total mass of the coarse fraction produced corresponded well with measured values, and although the concentration of Zn was considerably underestimated in the model, the produced coarse fraction was within the limits for utilization.
Michael Schuster - One of the best experts on this subject based on the ideXlab platform.
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digestions vs suspensions the influence of Sample preparation on precision and accuracy in total reflection x ray fluorescence analysis by the example of waste incineration fly Ash
Spectrochimica Acta Part B: Atomic Spectroscopy, 2019Co-Authors: Jasmin Haberl, Stephan Fromm, Michael SchusterAbstract:Abstract The elements K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, Pb, and Br in a fly Ash Sample from municipal waste incineration were determined by total-reflection X-ray fluorescence (TXRF) spectrometry. The fly Ash was analyzed after microwave-assisted digestion and in the form of suspensions, each with several modifications. The results of the different Sample preparation methods were compared with regard to precision and accuracy. Multiple Sample spots were prepared for each Sample preparation method, and the spread of the results was used as a measure of the precision. Accuracy was evaluated by comparing the median of the results with ICP–OES/ICP–MS analysis results. Additionally, the results were validated using a waste incineration fly Ash reference material. Different internal standards and the influence of adding a surfactant were tested for the digestion solution. For the suspensions, the fly Ash Sample was subjected to different grinding levels and suspended both in water and in 1% w/w nitric acid. Light microscope images were taken of the dried Sample spots on the Sample carrier, and their size and shape were visually compared. Some Sample preparation methods led to an inhomogeneous depth distribution of the analytes and/or the internal standard within the Sample spots. This inhomogeneity was detected by angle scans and was found to be a main reason for systematic errors and/or a low precision. With optimized preparation of the suspension and of the digestion solution, comparable precision could be achieved, even in the range of the instrument precision. A suited Sample preparation method that requires the least effort and least use of chemicals is presented for each element.
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solubility of elements in waste incineration fly Ash and bottom Ash under various leaching conditions studied by a sequential extraction procedure
Waste Management, 2019Co-Authors: Jasmin Haberl, Michael SchusterAbstract:Abstract An optimized 7-step sequential extraction was applied to fly Ash Samples from two waste incineration plants and a bottom Ash Sample. The solubility of 37 elements in water under alkaline and neutral conditions, ion exchange, acid solubility as well as the influence of reducing and oxidizing agents, were investigated using reagents which are typically applied in sequential extractions. Potential error sources and the suitability and selectivity of individual steps and extracting agents were also evaluated. Additionally, the amounts of total dissolved solids were determined for each extraction step, and the results were validated by comparison with the analysis data of the elemental composition. All the investigated incineration residues exhibited a very similar solubility behavior. Only the alkali metals in the bottom Ash were considerably less water-soluble than those in the fly Ash. The solubility behavior among the rare earth elements was alike. The pH of the fly Ash suspensions in water increased over several hours from neutral to alkaline. Concentration changes of water-soluble elements were investigated during the pH increase and to what extent precipitated elements can be re-dissolved by a subsequent neutralization. Meanwhile, it was shown that chloride ions in commonly used sequential extraction agents (e.g., MgCl2 and NH2OH·HCl) can influence the extractability of individual elements, which can lead to misinterpretations of the results. Using MgCl2 to study Mg2+ ion exchange led to the dissolution of Ag and Cd only caused by the chloride ions. Furthermore, the order of the reducing and oxidizing step was found to be interchangeable.
Liu Jin - One of the best experts on this subject based on the ideXlab platform.
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study on the polycyclic aromatic hydroncarbons for the Ash Sample of the municipal solid waste incinerator
Environmental Monitoring in China, 2003Co-Authors: Liu JinAbstract:A method was evaluated for the determination of Polycyclic Aromatic Hydroncarbons (PAHs) with Gas Chromatograph and Mass Spectrometer (GC/MS) in the Ash Sample of the municipal solid waste incinerator Using this method, the recovery ratios of 16 kinds of PAH was almost in the range of 80%～110%
Jasmin Haberl - One of the best experts on this subject based on the ideXlab platform.
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digestions vs suspensions the influence of Sample preparation on precision and accuracy in total reflection x ray fluorescence analysis by the example of waste incineration fly Ash
Spectrochimica Acta Part B: Atomic Spectroscopy, 2019Co-Authors: Jasmin Haberl, Stephan Fromm, Michael SchusterAbstract:Abstract The elements K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, Pb, and Br in a fly Ash Sample from municipal waste incineration were determined by total-reflection X-ray fluorescence (TXRF) spectrometry. The fly Ash was analyzed after microwave-assisted digestion and in the form of suspensions, each with several modifications. The results of the different Sample preparation methods were compared with regard to precision and accuracy. Multiple Sample spots were prepared for each Sample preparation method, and the spread of the results was used as a measure of the precision. Accuracy was evaluated by comparing the median of the results with ICP–OES/ICP–MS analysis results. Additionally, the results were validated using a waste incineration fly Ash reference material. Different internal standards and the influence of adding a surfactant were tested for the digestion solution. For the suspensions, the fly Ash Sample was subjected to different grinding levels and suspended both in water and in 1% w/w nitric acid. Light microscope images were taken of the dried Sample spots on the Sample carrier, and their size and shape were visually compared. Some Sample preparation methods led to an inhomogeneous depth distribution of the analytes and/or the internal standard within the Sample spots. This inhomogeneity was detected by angle scans and was found to be a main reason for systematic errors and/or a low precision. With optimized preparation of the suspension and of the digestion solution, comparable precision could be achieved, even in the range of the instrument precision. A suited Sample preparation method that requires the least effort and least use of chemicals is presented for each element.
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solubility of elements in waste incineration fly Ash and bottom Ash under various leaching conditions studied by a sequential extraction procedure
Waste Management, 2019Co-Authors: Jasmin Haberl, Michael SchusterAbstract:Abstract An optimized 7-step sequential extraction was applied to fly Ash Samples from two waste incineration plants and a bottom Ash Sample. The solubility of 37 elements in water under alkaline and neutral conditions, ion exchange, acid solubility as well as the influence of reducing and oxidizing agents, were investigated using reagents which are typically applied in sequential extractions. Potential error sources and the suitability and selectivity of individual steps and extracting agents were also evaluated. Additionally, the amounts of total dissolved solids were determined for each extraction step, and the results were validated by comparison with the analysis data of the elemental composition. All the investigated incineration residues exhibited a very similar solubility behavior. Only the alkali metals in the bottom Ash were considerably less water-soluble than those in the fly Ash. The solubility behavior among the rare earth elements was alike. The pH of the fly Ash suspensions in water increased over several hours from neutral to alkaline. Concentration changes of water-soluble elements were investigated during the pH increase and to what extent precipitated elements can be re-dissolved by a subsequent neutralization. Meanwhile, it was shown that chloride ions in commonly used sequential extraction agents (e.g., MgCl2 and NH2OH·HCl) can influence the extractability of individual elements, which can lead to misinterpretations of the results. Using MgCl2 to study Mg2+ ion exchange led to the dissolution of Ag and Cd only caused by the chloride ions. Furthermore, the order of the reducing and oxidizing step was found to be interchangeable.
Durjoy Mallick - One of the best experts on this subject based on the ideXlab platform.
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leaching of elements from coal fly Ash assessment of its potential for use in filling abandoned coal mines
Fuel, 2009Co-Authors: Binay K Dutta, Swapan Khanra, Durjoy MallickAbstract:Abstract Leaching of ten elements – namely, Fe, Mn, Ca, Na, K, Cu, Cr, Zn, As and Pb – from four fly Ash Samples collected from four different coal-fired thermal power plants in West Bengal, India, has been reported. The leaching conditions were selected to broadly simulate that of surface coal mines in order to estimate the usefulness of the materials for back-filling of abandoned mines and to assess the possibility of contamination of the sites by release of heavy metal ions. Sequential batch leaching consisted of four cycles each of seven days duration; the long-term leaching continued over a period of 180 days. The starting pH of the leaching solutions ranged from strongly acidic to strongly basic. The leaching pattern and its dependence on the pH as well as the solid–liquid ratio have been critically analyzed. A much higher mobility of the elements have been expectedly observed at a low pH. Less leaching is found at a high pH except for arsenic. The mobilization pattern is strongly governed by the well-known phenomenon of dissolution and re-precipitation of iron with co-precipitation of a series of elements depending upon the pH of the medium. Extraction equilibrium was reached for Ca, Fe, Na and Zn at certain pH values. A monotonic trend of release for the elements Mn, K, Cu, Pb, Cr and As persisted over the long-term leaching period of 180 days. The alkalinity or the calcium content of an Ash Sample greatly determines the leaching pattern if the solution pH is neutral or mildly acidic. It appears that the risk pollution of ground water as well as of surface water may not be avoidable if fly Ash alone is used for mine back-filling in an environment where acid mine drainage is prominent. Nevertheless blending with lime to enhance the alkalinity appears to offer a practical solution to the problem.
