Accumulation Of Fly Ash Research Articles

Axial compression performances and bearing capacity prediction of self-compacting fly ash concrete filled circle steel tube columns

To solve the problem of a large amount of fly ash accumulation and study the axial compression and bearing capacity prediction of the self-compacting fly ash concrete filled circle steel tube (SCCFST) columns, eight specimens are designed to explore the impact of concrete strength grade, internal structural measures, and additional parameters. The stress, progression of deformation, and failure mode of each specimen are observed during the loading process. The load–displacement curves, load-strain curves, characteristic load and displacement, ductility, and stiffness degradation are analyzed. The findings revealed that shear deformation occurred predominantly in the middle and upper portions of the steel tubes. Enhancing the strength of the concrete or adopting internal structural measures could increase the bearing capacity and ductility of the specimens. The peak load and ductility could be increased by up to 17.6 and 53.6%, respectively. The proposed unified calculation equation for the axial compression bearing capacity of SCCFST columns demonstrates notable reliability and precision. Furthermore, these tests offer valuable references for the engineering application of various forms of SCCFST columns, which are of significant importance in practical engineering.

Effect of fly ash on mechanical properties and microstructural behaviour of injected moulded recycled polypropylene composites

The global challenges of plastic waste and fly ash accumulation demand innovative recycling solutions. In Malaysia, the consumption of 11.2 million tonnes of coal annually generates approximately 2 million tonnes of fly ash, while the recycling of Polypropylene (PP) is hindered by thermo-oxidative and shear-induced degradation during mechanical recycling, resulting in reduced mechanical properties. This study addresses these issues by fabricating recycled PP composites incorporating varying fly ash contents, using a single cycle of mechanical recycling with extrusion and injection moulding methods. The composites were comprehensively tested for tensile, flexural, and compressive strengths, as well as microstructural behaviour. The results reveal a complex relationship between fly ash content and mechanical performance: while tensile strength decreases with increasing fly ash, flexural strength and strain peak at 5 % and 9 % fly ash, respectively. Compressive strength also shows a slight increase up to 7 % fly ash, indicating an optimal range for enhancing mechanical performance. Furthermore, mathematical models were proposed to predict the mechanical properties of rPP – fly ash composites, providing a valuable tool for future material design. These findings demonstrate that optimization of fly ash content can mitigate the effects of polymer degradation, offering a sustainable solution to improving the mechanical performance of this composite.

Оценка золошлаковых отходов как источника загрязнения окружаюшей среды и источника вторичного сырья

Introduction. Currently, more than 500 million tons of fly ash have been accumulated on the territory of the Republic of Kazakhstan, the volume of which will increase to one billion tons by 2030. Such accumulation of fly ash in storages creates a powerful anthropogenic impact on the biogeocenosis. A significant proportion of these man-made materials are formed during the burning of Ekibastuz coals. There is practically no processing of ash and slag waste on an industrial scale. For various reasons, ash dumps are not used in Kazakhstan, because the physico-chemical properties have been very poorly studied, in addition, during their processing, other wastes or ash dumps unsuitable for use are obtained from these wastes, because they contain a lot of unburned coal. As of 01.01.2020, the share of recycled, reused, burnt ash and slag waste in Kazakhstan amounted to 0.7%. The relevance and significance of this problem is due to the fact that man-made waste from CHP plants is not sufficiently processed, and current ash waste accumulates and occupies huge areas, which removes them from land use. Knowledge of the chemical composition of the ash will allow it to be used to obtain building materials. The purpose of this work is to study the properties of ash and slag waste during the burning of coal from the Ekibastuz deposit in Kazakhstan, to assess them as a source of environmental pollution, to determine the possibility of obtaining demanded building materials from them. Research methods. To determine the phase composition of the studied material, an upgraded diffractometer DRON-3M on CuKa radiation with software was used. Radiographs of the sample were obtained in the range of 2° (angles) from 10 to 70°. The chemical composition was determined using an energy dispersion spectrometer “EDX-8000”. Micrography of fly ash was taken on a scanning electron microscope Superprob-733. Research materials. Ash and slag waste from the burning of coal from the Ekibastuz deposit in Kazakhstan. Research results and discussion. The physical characteristics of ash have been established: specific surface area – ~200 m2/kg, true density – 2.1 g/cm3, bulk density – ~780 kg/m3. Fractional composition: the highest content of particles with a size of 100 microns (25.8%), 80 microns (12.12%), 50 microns (21.46%) and 45 microns (21.38%); at the same time, unburned carbon is concentrated in large fractions, glass phase – in small ones. Analysis of the chemical composition of Ekibastuzky ash allowed to find out the composition of coal minerals. The main components are silicon and aluminum oxides, and there is also a large amount of iron oxide. Knowledge of the chemical composition of ash allows it to be used in the production of building materials. Conclusion. The results of the conducted studies have shown the possibility of using ash and slag waste as secondary raw materials in the construction of road materials in order to reduce the anthropogenic load on the environment.

Synthesis of a high-iron fly-ash-based Na-X molecular sieve and its application in the adsorption of low concentration of CO2.

In addressing the environmental challenges posed by the accumulation of fly ash (FA), efforts have been geared towards its high-value utilization. By the use of high-iron FA as a raw material, a high-iron fly-ash-based Na-X molecular sieve was successfully synthesized by hydrothermal method. We combined pretreatment methods such as high-temperature calcination, acid leaching and alkali fusion activation. The as-synthesized product was used for the adsorption of a low concentration of CO2, and the adsorption data were fitted by a physical model. The changes in iron content in pretreatment and molecular sieve synthesis were revealed by SEM-mapping, UV-Raman and UV-Vis. The results showed that the pretreatment process reduces the iron content from 32.3% to 13.3%, and converts the inactive phases to active phases, with n (SiO2/Al2O3) = 4.94. The activated product was transformed further to a Na-X molecular sieve using a hydrothermal method. The product has a single crystal phase and octahedral crystal structure. Its specific surface area was 646.634 m2 g-1, and micropores were distributed between 0.46 nm and 0.71 nm, with a mesoporous phase of 4.6 nm. When used to adsorb a low concentration of CO2, the Na-X molecular sieve has a high adsorption capacity of 3.70 mmol g-1, which reaches 95.11% that of the commercial Na-X molecular sieve. The adsorption breakthrough time and adsorption capacity decreased with an increase in temperature. The adsorption kinetics were consistent with the Bangham model for surface pore adsorption and Weber-Morris model for internal diffusion. During the synthesis process, iron was converted from highly dispersed iron oxide to four-coordinated framework iron. Thus, this paper paves a path for the high-quality transformation and utilization of high-iron fly-ash.

Application of CO2-loaded geopolymer in Zn removal from water: A multi-win strategy for coal fly ash disposal, CO2 emission reduction, and heavy metal-contaminated water treatment

Coal fly ash accumulation, global warming, and heavy metal-contaminated water environments are three primary environmental concerns. Porous geopolymers are economical porous adsorbents that can be produced using coal fly ash as a raw material and employed for heavy metal removal from water. However, residual alkalis on the geopolymer can lead to extreme increases in pH and cause environmental stresses, which limits the large-scale production and application of geopolymers in industries and environments. A green approach to alleviating the high basicity of geopolymers through CO2 exposure is proposed, with CO2 adsorption experiments as well as Zn removal batch and column experiments conducted to evaluate the practicality of the synergistic strategy. CO2 adsorption experiments show the CO2 capture capacity of fresh geopolymer (F@PG) is 0.80 mmol g−1, greater than that of the conventionally washed geopolymer (W@PG, 0.26 mmol g−1), with the pH of the geopolymer decreasing after both washing and CO2 exposure. Batch experiments suggest neither washing nor CO2 exposure cause a significant change in the Zn adsorption capacity of the geopolymer; column experiments show the CO2-exposed geopolymer (C@PG) has a pH < 9.5 and a satisfactory Zn removal performance similar to W@PG, but F@PG with a pH ∼12 results in a conversion of Zn to anionic forms and a decrease in Zn removal efficiency. These results indicate CO2 exposure is a practical method to decrease the pH of geopolymers for applications related to heavy metal-contaminated water treatment and provide a large-scale industrial option for coal fly ash consumption and CO2 emission reduction.

Coal fly ash application as an eco-friendly approach for modulating the growth, yield, and biochemical constituents of Withania somnifera L. plants.

The solid waste known as fly ash, which is produced when coal is burned in thermal power plants, is sustainably used in agriculture. It is an excellent soil supplement for plant growth and development since it contains some desired nutrients (macro and micro), as well as being porous. The present study was done to evaluate the effect of different fly ash levels on Withania somnifera. The present study aimed to assess the impact of various fly ash (FA) concentrations on growth, yield, photosynthetic pigments, biochemical parameters, and cell viability of W. somnifera. The results showed that FA enhanced physical and chemical properties of soil like pH, electric conductivity, porosity, water-holding capacity, and nutrients. The low doses of FA-amended soil (15%) significantly increased the shoot length (36%), root length (24.5%), fresh weight of shoots and roots (107.8 and 50.6%), dry weight of shoots and roots (61.9 and 47.1%), number of fruits (70.4%), carotenoid (43%), total chlorophyll (44.3%), relative water content (109.3%), protein content (20.4%), proline content (110.3%), total phenols (116.1%), nitrogen (20.3%), phosphorus (16.9%), and potassium (26.4%). On the other hand, the higher doses, i.e., 25% of fly ash showed a negative effect on all the above parameters and induced oxidative stress by increasing lipid peroxidation (33.1%) and hydrogen peroxide (102.0%) and improving the activities of antioxidant enzymes and osmolytes. Compared to the control plants, the plants growing in soil enriched with 15 and 25% fly ash had larger stomata pores when examined using a scanning electron microscope. In addition, according to a confocal microscopic analysis of the roots of W. somnifera, higher fly ash concentrations caused membrane damage, as evidenced by an increase in the number of stained nuclei. Moreover, several functional groups and peaks of the biomolecules represented in the control and 15% of fly ash were alcohols, phenols, allenes, ketenes, isocynates, and hydrocarbons. Gas chromatography-mass spectrometryanalysis of the methanol extract of W. somnifera leaves cultivated in soil amended with 15% fly ash shows the presence of 47 bioactive compounds. The most abundant compounds in the methanol extract were cis-9-hexadecenal (22.33%), n-hexadecanoic acid (9.68%), cinnamic acid (6.37%), glycidyl oleate (3.88%), nonanoic acid (3.48%), and pyranone (3.57%). The lower concentrations of FA (15%) can be used to enhance plant growth and lower the accumulation of FA that results in environmental pollution.

Basic properties, characteristic heavy metals leaching and migration of coal incineration fly ash-based mortar

Accumulation of fly ash causes waste of land resources and certain environmental pollution problems, mainly from coal incineration. As a result, to investigate the leaching, migration law, and environmental safety of these distinctive heavy metals, this study used representative fly ashes from two power plants as research objects to screen out the characteristic heavy metals and prepare and test mortar specimens. The results of the study show that after four heavy metal risk assessment methods, it was concluded that the characteristic heavy metals where are in A power plant’s fly ash were Hg, Cr, Pb and As, and in that of power plant B were Hg and As. The best fly ash admixture was 20% and the best water-binder ratio was 0.48, as learned from the compressive strength experiment. The heavy metal leaching test was done for block mortar and crushed mortar on the use of the best mix ratio. When compared to the raw materials, the specimens' heavy metal leaching content was significantly lower. And the heavy metals in crushed mortar were easier to leach. After the analysis of the migration transformation model, the heavy metals migrated downward in the mortar under the action of gravity. According to the one-dimensional diffusion model of Fick's second law, the migration of the various characteristic heavy metals was ranked from strong to weak as Pb, As, Cr, and Hg, and the ranking of the maximum safe age was ranged from large to small as Hg, Pb, Cr, and As. The findings of the study will provide fundamental theoretical support for the environmental safety risk posed by heavy metals and safety controls like the leaching of characteristic heavy metals in current fly ash-based mortar products. They will also provide further guidance on how to use fly ash as a resource.

Risk assessment of naturally occurring radioactivity in soil adjacent to a coal-fired brick kiln

Being aware of the potential health effects brought on by exposure to radionuclides, besides chemical and air pollution, produced by coal-fired brick kilns, first-ever measurements of terrestrial radionuclides were performed in the topsoil sampled from the surrounding of a randomly chosen coal-fired brick kiln operating at the outskirts of megacity Dhaka, Bangladesh. By employing the HPGe gamma-ray spectroscopy, the activity concentrations of 226Ra, 232Th, and 4 K was found to be in the range of (19.2 ± 2.7–54 ± 7.0) Bq/kg, (33 ± 5.3–68 ± 9.5) Bq/kg, and (360 ± 43–540 ± 65) Bq/kg respectively, where almost all the values of 40 K, 232Th; and some of the values of 226Ra exceeded the corresponding world average values. Possible causes of the elevated level of radionuclides include the deposition of bottom ash in lowlands, the accumulation of fly ash in soils, and the fallout of fine particles that absorb the minerals released from the coal burning process. 137Cs was also found in two samples that might indicate contamination of the feed coal. Most of the outdoor absorbed dose rates, some internal absorbed dose rates, annual effective dose, gamma level index and excess lifetime cancer risk surpass the worldwide average. According to these hazard parameters, there are health risks to the brick kiln workers and the populace who consumes food crops produced in the studied agricultural soils. The present quantitative measurements urge the municipal authorities to manage and monitor the discharge of fly ash from the brick kilns and take precautionary actions to reduce unwanted health hazards. It also demands to monitor of the human health of workers and residents near the brick kilns.

Analysis of the Impact of Fly Ash on Environmental Pollution (Case Study of Pulp and Paper Pangkalan Kerinci)

The accumulation of fly ash in large quantities will cause problems for the environment, such as air and water pollution and a decrease in the quality of ecosystems containing Ni, V, As, Be, Cd, Ba, Cr, Cu, Mo, Zn, Pb, Se and Ra which can affect groundwater quality and human health. This study aims to analyze the impact of waste generated from the Pulp and Paper on the environment around the industry. The data obtained is in the form of primary data from the results of the Toxicity Characteristic Leaching Procedure (TCLP) test and direct observation in the field to identify environmental conditions around the landfill, while TLCP laboratory analysis was carried out to determine the toxic characteristics of TLCP in fly ash from the Pulp and Paper BaseKerinci. The TCLP test results for fly ash the analyzed waste Fly ash produced from the pulp and paper is suitable for use with fly ash class F2+A12O3+Fe2O3 content of 75.19%. Utilization of fly ash can be an effort to reduce the impact of fly ash on environmental pollution. The waste produced by pulp and paper obtains a metal value below the quality standard so that it does not have a negative impact on the surrounding environment.

Dynamic Response of Cement–Fly Ash Mixed Pile Composite Foundation Under Wave Load

CFMPs (cement and fly ash mixing piles) are used to reinforce fly ash foundation to solve the problem of a large amount of fly ash accumulation in coastal areas. CFMP-fly ash composite foundation is used as the foundation of coastal and coastal engineering. Through the indoor model test, the bearing characteristics and load transfer mechanism of CFMP-fly ash composite foundation under wave load were investigated. The results show that with the increase of wave load, the horizontal resistance of the fly ash stratum increases gradually, the soil resistance moves down, and the level of resistance shows nonlinear characteristics. The pile bending moment, pile displacement, and horizontal resistance of the CFMP composite foundation are concentrated in the upper pile and fly ash stratum, which can improve the ability of the composite foundation to resist horizontal load by improving the physical and mechanical properties of the upper fly ash stratum. Through the calculation of the load–displacement curve, it is found that the measured displacement value is closer to that obtained using the p–y curve method (a method for solving nonlinear lateral resistance of piles). The hysteretic curve area of cyclic loading decreases with the increase of cyclic number. The accumulation of elastoplastic deformation of pile shows that the properties of fly ash gradually change to elastic stage, cyclic loading can reduce the horizontal deformation modulus of composite foundation CFMP caused pile—fly ash system of weakening, in peak load reaches level under the critical state displacement curve showed a trend of the rapid growth of nonlinear, cyclic cumulative failure occurs, and the cyclic load limit state is reached, which affects the service performance of the whole structure.

Coal fly ash and nitrogen application as eco-friendly approaches for modulating the growth, yield, and biochemical constituents of radish plants

Plants are confronting a variety of environmental hazards as a result of fast climate change, which has a detrimental influence on soil, plant growth, and nutrient status. As a result, the present study aims to evaluate the influence of various fly ash concentrations (5, 10, 15, 20, 25, 30, and 35% FA) mixed with the optimum concentrations of nitrogen in the form of urea (0.5 g pot−1) on the growth, productivity and biochemical constituents of radish plants. Energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM) were used to assess soil physical–chemical properties and FA nutrient status. Results suggested that FA added many essential plant nutrients to the growth substrate and improved some important soil characteristics such as pH, electric conductivity, porosity, and water holding capacity. Also, the results revealed that the low concentrations of FA up to 20% were found to boost radish growth, yield, chlorophyll, carotenoids, and mineral content. While the highest concentrations of FA (25–35%) decreased radish growth and yield, increased oxidative stress through increased lipid peroxidation (MDA) and caused a significant boost in ascorbic acid, proline, protein, and antioxidant enzyme activities. Furthermore, SEM of radish leaf revealed an enhancement in the stomatal pore of radish leaf under different levels of FA. In conclusion, combining 15% fly ash with 0.5 g nitrogen in the form of urea significantly enhanced radish yield by enhancing antioxidant activity such as catalase, peroxidase, ascorbate peroxidase, Guaiacol peroxidase, superoxide dismutase, nitrate reductase and reducing oxidative stress, potentially reducing fly ash accumulation and environmental pollution.

Influence analysis of the different ash plane in the waveguide on the measurement of the carbon content of the fly ash by the microwave method

Microwave attenuation method has been one of the possible methods to measure the carbon content in fly ash online with high accuracy in recent years. However, the uncertainty of the shape of fly ash accumulation in waveguide brings many errors to the measurement of carbon content. To correct the errors, based on the study of ash level measurement, the influences of different inclined planes on the measurement of medium height and transmission attenuation are compared. Then, a model was established to quantify the influence of slope degree on carbon content of fly ash. Finally, the interference of different inclined planes on the measurement of carbon content in fly ash is analyzed. The result shows that with the increase of the inclination angle of the dielectric top slope in the waveguide, the transmission attenuation effect gradually increases. This will lead to the large measured value of carbon content in fly ash.

Eluviation and Leaching of Elements from Broken Fly-Ash-Based Porous Geopolymer.

The fly ash from powerplants used for coal mine end backfilling can effectively reduce the impact of ground fly ash accumulation on the environment. However, due to the long-term action of the overlying strata and groundwater, when the backfilling body is broken, heavy metals will also be leached, thus having an impact on the groundwater. Therefore, in this paper, the eluviation and leaching of elements from a broken fly-ash-based porous geopolymer is studied. The fly-ash-based geopolymer material was prepared to perform a dynamic eluviation and static leaching test, and it was found that the amount of Cu and Zn in the leachate was less abundant, whereas Pb was more abundant, but far less than the limit of the Class III groundwater quality standard. An acidic environment and a smaller solid–liquid ratio can promote the leaching of Cu and Zn, while the leaching of Pb is basically unaffected by the pH value. Moreover, the amount of Cu, Zn, and Pb in the lixivium increased with the increase in leaching time, and the amount of Cu and Zn in the lixivium was still low after 150 h of leaching, whereas the amount of Pb was high, approaching the limit value of the Class III groundwater quality standard, showing a tendency to increase after 100 h of leaching. A leaching orthogonal experiment was designed, and the results showed that the main order of each factor affecting the leaching of heavy metals from the fly-ash-based geopolymer was grain size > pH > solid–liquid ratio; thus, the leaching of heavy metals from fly-ash-based geopolymer can be controlled, which is significant with respect to the extensive use of fly-ash materials underground.

Investigation of fly ash soiling effects on solar modules performances

The increase of solar modules installation worldwide has led to an increase in the investigation of the phenomena that may cause adverse effects on the performance of solar modules, such as soiling. Soiling of solar modules surface leads to a reduction in their performance due to reduced quantity of solar radiation reaching solar cells. Having in mind that (in Serbia) solar modules on the roofs are often located near chimneys, and that for heating fossil fuels are mostly used, during the heating season fly ash is accumulated on solar modules reducing their performances. This paper presents results of the outdoor experimental investigation of the impact of accumulated fly ash during the heating season on solar modules surface set at an angle of 0° (horizontal), and at an optimal angle of 32° for the area of ​​Niš on their power. The experiment was carried out for a period of 168 days. The maximum power reduction (greatest reduction of solar modules power due to fly ash soiling) both for the horizontal and optimally installed module due to the fly ash accumulation was measured on the 45th day of the measurement. The maximum power reduction of the horizontal module was 87.2%, and of the optimally set module 30.6%. The morphology of the fuel oil fly ash was analyzed using scanning electron microscopy (SEM). The fly ash particles were generally spherical in shape, of a porous structure and the largest number of particles had diameters of 20 μm to 50 μm.

SaskPower’s Boundary Dam Unit 3 Carbon Capture Facility - The Journey to Achieving Reliability

SaskPower’s Integrated Carbon Capture and Storage Project on Boundary Dam’s Unit 3 (BD3 ICCS) began operations in October of 2014. By early October 2020, the facility had captured its 3.5 millionth metric tonne of carbon dioxide (CO2). The road to 3.5 million tonnes of CO2 abated was not without difficulties. As a “first of kind” project, the capture facility at BD3 has been a platform for in-depth learning and optimization. The capture facility experienced unforeseen operational challenges and design oversights which hindered overall performance and significantly reduced its reliability and availability in the early days of operation. Availability of the capture facility did not exceed 70% during the first year and a half of operations while the average daily capture rate in the first 12 months of operation was merely 1240 tonnes/day. Based on experience, reduced capture performance can be attributed to difficulties in three broad categories of process flows: limitations in flue gas flow, limitations in amine flow, and limitations in heat transfer. Equipment responsible for facilitating these flows was identified. Major issues included fly ash accumulation, fouling of key heat exchangers and amine foaming. Corrections and additions to the capture facility were made to increase the facility’s reliability and availability. Corrections and additions to the capture facility including the installation of redundancy and isolations to key pieces of equipment was instrumental in correcting the performance of the facility, increasing its reliability and availability. By the summer of 2019 (May to July) the daily average capture rate was 2580 tonnes/day while availability in the 2018 to 2019 period had improved to over 90%. This paper documents the challenges and measures taken over the first five years of operations to improve the performance of the BD3 ICCS facility.

Experimental Study on the Basic Properties of a Green New Coal Mine Grouting Reinforcement Material

Waste tires are internationally recognized as hazardous waste. Many waste tires storing in the open air for a long time will not only waste the land resources but also pollute the environment after the incineration. Meanwhile, the cumulative accumulation of fly ash in China has also been one of the largest sources of solid waste in coal mines. Under the action of high winds, the accumulated fly ash forms flying dust, which pollutes the environment and endangers human health. Herein, a new type of grouting material for floor reinforcement was developed based on solid waste products using the waste tire rubber particles and fly ash. Using this new material, disaster accidents such as flooding and casualties caused by the inrush of the floor-confined water due to floor fractures, activation, and expansion in the mining process can be greatly reduced, thereby ensuring the safety of coal mine production. The grout body was prepared using a large amount of fly ash, waste tire rubber particles and clay, and mixing additives. The ratio optimization test, uniaxial compressive strength test, permeability characteristic test, stability test, and microanalysis of mine water environment were performed. From the test results, the macrophysical and chemical properties including optimal mix ratio, compressive strength, permeability coefficient, and stability of mine water environment were obtained. The microstructural properties of the grouts were analyzed using scanning electron microscopy microanalysis methods. Considering the situation of the coal floor and attempting to use as many solid waste products as possible, the optimized proportion that can meet the requirements of low cost, high bonds, and dense filling is as follows: 20% of rubber particles, 65% of fly ash, 15% of clay, and 1% of nanosilica. Furthermore, this study can provide scientific reference for large-scale floor grouting reinforcement and large-scale utilization of solid waste products.

Experimental investigation on thermal behavior of fly ash reinforced aluminium alloy (Al6061) hybrid composite

In the present study, the thermal behavior of pure Al6061 and fly ash reinforced Al6061 with varying particulate sizes were investigated for the first time. Metal matrix syntactic foams of ceramic fly ash (4 – 16 wt. %) embedded in aluminum (Al6061) matrix have been fabricated by using stir casting technique with different fly ash particulate sizes of size below 50µm and 53µm-100µm, respectively. The microstructural characteristics were studied by using scanning electron microscopy (SEM). It has been observed that there is a uniform distribution of lower particulate size fly ash as compared to higher particulate size in the aluminium matrix respectively. For all the cases, the accumulation of fly ash in Al6061 decreases the thermal conductivity and increases the specific heat carrying capacity of a hybrid composite. Increase in weight percentage of fly ash in Al6061 decreases thermal conductivity and thermal diffusivity respectively.

A conjugative study of Typha latifolia for expunge of phyto-available heavy metals in fly ash ameliorated soil

With the ever-increasing demand for coal, the drawbacks associated with it also increase. Accelerating accumulation of fly ash, a byproduct in coal combustion processes, is of major environmental concern at present. Fly ash finds its maximum utilization in concrete and cement factory due to its pozzolanic property. However, fly ash is also used in the agricultural division as a “fertilizer” especially in West Bengal. However, there is no upper limit to how much fly ash should be added to agricultural soil. Current study deals with fly ash, that has been mixed with soil in four proportions namely, 0% (FA0), 25% (FA25), 50% (FA50) and 75% (FA75). A wetland emerged plant – Typha latifolia - has also been incorporated in the system. Mobility and metal(loids) relation has been established determining soil-ash physico-chemical properties along with nutritional enrichment to the plant system. Sequential Extraction methods are therefore employed to examine the element speciation. Application of 25 percent Fly ash was found to enhance the N(0.11%), P(0.09%), K(0.051%) and Si(7.7%) availability in soil and also resulted in better plant growth and xylem integrity as justified by electron microscopic observation. At end of final sampling, total arsenic concentration was 50.07±0.25mgKg–1 in Typha associated sample comparing to 59.51±0.19mgKg-1 in without Typha system using 25% ash. This study reflects the utility strategies of fly ash and Typha latifolia in combination for the better expunge of phyto-available metals form agricultural soil during a stop gap, before further crop production particularly another wetland plant, rice.

Anthropogenic particle dispersions in topsoils of the Middle Nile Delta: a preliminary study on the contamination around industrial and commercial areas in Egypt

Increased industrialization has adversely affected various components of the environment including soil, which is the ultimate site of settling and accumulation of fly ash. Fine respirable size particles in the atmosphere are detrimental to human health and their ultimate accumulation in the soil leads to soil pollution. In this study, these particles were identified, quantified and subjected to intensive analysis by SEM/EDX. Accordingly, the physical and chemical characteristics, the origin and the pathway of such particulates are documented for the Middle Nile Delta using the magnetic susceptibility as proxy for the industrial emissions. The average bulk density of magnetic spherules varies between 4.4 ± 0.7, 4.8 ± 0.9 and 5.4 ± 0.6 g/cm3 for the >125, 63–125 and 36–63 μm fractions, respectively, and consists predominantly of iron oxides with variable amounts of Ti, Si, Mn, Mg, Al, Ca, Cr and Cu. Their attached grains and adhesive materials are commonly composed of various contents of Si, Al, Fe, Ca, P, Zn, Ba and S depending on their origin. The results indicated that most surface soil samples are enhanced magnetically than the natural local background magnetic signal due to atmospherically deposited urban dust. The industrial sites are characterized by highest average magnetic susceptibility value (47 × 10−5 m3g−1) combined with highest concentration of magnetic spherules (66 sph.g−1). Moreover, the residential area surrounding industrial zones—particularly those located in the windblown (SE) direction—is seriously affected by industrial dust. This study provides a database to evolve strategies for remedial measures to minimize environmental degradation.

Mineralogical Studies of Coal Fly Ash for Soil Application in Agriculture

Coal fly ash procured from Guru Gobind Singh Super Thermal Power Plant, Ropar, Punjab, India, was analyzed for its mineralogical content and thermal stability by x-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and physicochemical properties. XRD studies showed that major crystalline phases observed were quartz (SiO2) and aluminum silicon oxide (Al4.52Si1.48) with macro- and microelement (N, P, K, Mg, Zn, S, and Fe). Fly ash showed thermal stability up to 500°C and reduction in weight was up to 200°C, primarily due to loss of water and decarboxylation as revealed by TGA plots. FTIR of fly ash showed that the most prominent peaks in the spectra corresponded to Si–O and Al–O stretch vibrations. Coarse-grain accumulation of fly ash indicated the presence of 70% of fine-grained particles of 0.075 mm. Coal fly ash was alkaline in nature (pH 7.85 ± 0.03) with an electrical conductivity of 0.14 ± 0.02 µS m−1, water holding capacity of 62%, low bulk density of 0.99 g cm−3, and a surface area of 0.96 m2 g−1. With properties similar to that of soil coal, fly ash represents a suitable material for use in specific quantities as a soil amending agent in agriculture.