Pond Ash Research Articles

Loose Ash Fills Reinforced With the High Confined Encased Stone Columns: Experimental and Numerical Investigation

The use of industrial waste (ash) in large-scale earthworks for civil engineering applications such as construction of highway embankments, the rise of ash dykes, the filling low-lying areas, fillings of buildings, solves the problem of waste disposal besides in addition to the conservation of the natural soils. It is has a low density, low consolidation, lower potential for bearing and higher settlement. To use these areas for construction purposes, it is necessary to reinforce them at deeper depths. The present study uses highly confined stone columns to investigate the strengthening of ash fills. A total of six cases are investigated, including slope reinforced with an encased stone column. Model tests were conducted with pond ash at 40% relative density with a circular footing on untreated and treated ash fills. The enhanced cases include ordinary stone columns,vertically encased columns with geotextile, vertically encased columns with geogrid, highly confined vertically encased columns with both geotextile and geogrids (HC-1) and highly encased columns with both vertical encased geotextile and horizontal geogrid (HC-2) layers. The parametric study includes an examination of load-settlement behavior, load-carrying ratio, settlement reduction ratio, and stiffness factor, modulus of subgrade reaction and post-failure behavior of slopes reinforced with encased stone columns. In all cases, the high confined encased system yields better results. In each case, the stone column failure pattern of was observed at a distance range of 1–3 times the stone column diameter. Post-failure behavior indicates that for steep slopes where massive slip failures are expected, highly confined encased stone columns can be useful. Results are validated by the numerical modelling analysis of Plaxis.

Thermal Power Plant Waste By-product and Its Utility in Concrete

Nearly 117 coal based thermal power station has working conditions in India. About 71% (169 x 103 MW) electricity is generated from four Indian regions i.e. Western, Northern, Eastern, and Southern. All these thermal power plant has produces by-product after burning coal as an energy inputs. The by-product obtained in the form of fine ash which has been known as fly ash and bottom ash. These by-products directly dump on the nearby area or thrown into low lying areas. The utility of these finer materials has proven a feasible substance in the concrete constituents. The paper presents possible advantages to incorporate it into concrete. Fly ash, bottom ash and pond ash has potential to act as a binding and filler agent in concrete.

Stress-Strain Behaviour of Compacted Pond Ash Reinforced with Stone Column

Ash pond deposits are characterized by its high compressibility and low bearing capacity which is unappropriated for the construction of engineering structures over it. There are several techniques to improve the bearing capacity of ash deposits. Stone column is one of the effective techniques employed to increase the bearing capacity for construction of engineering structures over soft soil deposits. Stone columns are extensively used to improve the bearing capacity of poor ground, time rate of settlements, stiffness, reduce the settlement of structure, and liquefaction potential of soft ground. This paper reports the load settlement behaviour of compacted pond ash beds reinforced with stone columns. Both end bearing and floating stone columns of different length ratios and area ratios were introduced in compacted pond ash beds having different densities. The load-settlement behaviour of footings supported on different configurations of stone columns was studied.

Protocol for measuring indoor exposure to coal fly ash and heavy metals, and neurobehavioural symptoms in children aged 6 to 14 years old

IntroductionFly ash is a waste product generated from burning coal for electricity. It is comprised of spherical particles ranging in size from 0.1 µm to over 100 µm in diameter...

Sagardighi Ash Pond: A New Water Bird Habitat in Murshidabad district, West Bengal, India

Flyash is a waste product generated from coal based thermal power plants. Dumping the ash in nearby wastelands is most preferred disposal method. Literature review has shown that despite the toxic nature of flyash, these ash ponds sites harbour significant avian diversity. Avifauna is an important indicator to evaluate different habitats both qualitatively and quantitatively. The Ash Pond of Sagardighi Thermal Power Station, Murshidabad is situated at 24°37’88” N and 88°09’11” E, 36 msl. It is a large water body of average 20m deep. It is rain fed and also fed by water of Sagardighi Thermal Power Plant. This investigation was carried out during November, 2018 to March, 2020. Assessment of the avian diversity in the Sarardighi Ash pond in Murshidabad revealed that of the 42 species of aquatic birds found in this area, 16 are migratory species, 3 are local migrant and 23 species are residential in nature.  The checklist of these birds, along with their IUCN status has been prepared. This paper provides an overview of status of wetland birds in Sagardighi Ash Pond, Murshidabad

Rare earth element distributions in rivers and sediments from the Erdenet Cu–Mo mining area, Mongolia

River water and sediments collected from the Erdenet, Gavil, and Khangal Rivers, near the Erdenet Cu–Mo mine were analyzed for their rare earth elements (REE) and yttrium (YREE) contents. Surface water samples were also collected from the tailing pond and ash pond of the mine, as well as in the seepage from the ash pond, where a part of the effluent flows into the Khangal river. The major chemical compositions of river and surface waters were found to vary slightly with water flow. The river water is Ca–HCO3-dominated in the upstream of the Erdenet and Gavil Rivers and ash pond; Ca–SO4-dominated in the tailing pond and seepage from the ash pond; and Ca–HCO3–SO4-dominated downstream of the Erdenet and Khangal Rivers. Both river and surface water exhibited a significant diatom content and the dissolved organic matter mainly comprise of fulvic acid-like materials, protein-like materials and microbial materials.The concentrations of YREE in river and surface waters ranged from 4.6 to 14.9 ng/L, whereas those of the sediments and rocks were 10–43 mg/kg and 25–34 mg/kg, respectively. Shale-normalized YREE patterns of river and surface waters, irrespective of water type, were characterized by enrichments in the middle REE (MREE) and heavy REE (HREE) relative to the light REE (LREE), exceptionally positive La anomalies, and super-chondritic Y/Ho ratios. The predominant REE species were REE(CO3)2−, REECO3+, and REESO4+ in the Ca–SO4-rich water. The HREE enrichment in both river and surface waters resulted in stronger complexation with carbonate ions and fulvic-acid like materials with increasing atomic number and preferential sorption of LREE onto sediments in neutral to slightly alkaline pH water. The YREE patterns of sediments showed MREE enrichment. Total YREE contents in the river sediments were correlated with Fe2O3, P2O5 and loss on ignition (LOI), suggesting the MREE enrichment fractionated by precipitation of authigenic MREE-enriched minerals such as phosphate, Fe (oxy)hydroxides and organic matter. With the exception of La, there were significant correlations among neighboring YREE concentrations, indicating that most YREEs were fractionated by the same geochemical processes, such as aqueous complexation and sorption onto the sediment surfaces. The concentrations of La did not correlate with those of the other YREE, suggesting that the La anomaly was probably induced by a biogenic activity such as diatom blooming and/or anthropogenic processes. Our results provide better understanding of REE behavior because of (bio)geochemical and anthropogenic contamination in terrestrial water systems.

Coal fly ash exposure and affective disorders in children aged 6 to 14.

Background: Fly ash, a waste product generated from burning coal for electricity, contains neurotoxic heavy metals, like arsenic and manganese. Fly ash is stored in landfills and surface impoundments, which may potentially expose communities to fugitive dust emissions. Small particles that escape from the storage facilities may cause affective disorders in children. Affective disorders include depression, bipolar disorder, and anxiety and have been estimated to impact about 7% of children according to the CDC. Although the toxicity of fly ash is great, limited information exists on the neurobehavioral impact of exposure to fly ash.Methods: We measure fly ash and neurobehavioral disorders in children living near coal ash storage facilities. Using personal modular impactors and lift tapes, we collect particulate matter that is analyzed for fly ash by scanning electron microscopy and energy dispersive x-ray spectroscopy. The child behavior checklist (CBCL) is used to collect information on neurobehavioral outcomes. Logistic regression was used to assess the association between fly ash and affective disorders. Odds ratios were adjusted for age and gender.Results: To date, we have enrolled 229 children, 45% who are female. The mean age is 10.8 years (SD=2.53) and 77% are white. The mean value of indoor PM10 is 22.6 µg/m3 (SD=17.6; Min=3.83, Max=164) and 45% of homes had fly ash. Overall, 14.4% of children had affective disorders. Children who were exposed to fly ash were 1.84 more times likely to have differences in mood and anxiety (AOR=1.84, 95% CI = 0.86-3.96).Conclusion: Although we have not yet collected our full sample of children (N=300), there may be a potential relationship between fly ash exposure and affective disorders in children. Fly ash storage is an emerging environmental health threat throughout the world. This study may provide impetus for understanding the health impacts from exposure and promote improved regulations.

Modification of ACI209R-92 Concrete Shrinkage Model for Partial Replacement of Cement with Fly Ash and Sand with Pond Ash

Abstract A lot of researchers have been committed to studying various mathematical models for forecasting shrinkage strain developed in concrete and have found many computational models. Those models only predict the linear shrinkage of concrete. But volumetric shrinkage gives clear ideas about shrinkage strain produced inside the structure. However, the previous investigation usually focused on the shrinkage of control cement concrete or cement was replaced with one kind of supplementary cementitious material. The influence of multiple supplementary materials as both cement and sand replacement on shrinkage has not been studied, and this is very important in practice for saving cement and sand. In this research, cement has been replaced with fly ash up to 40 % and sand has been replaced with pond ash up to 20 % individually as well as simultaneously. A total of 27 mixes has been prepared by using three water–cement ratios, and the influence of fly ash and pond ash on volumetric shrinkage has been studied. It is found that when cement is replaced with fly ash up to 40 %, the shrinkage of concrete shows 47 % less than the shrinkage result of control concrete. Similarly, the replacement of sand with pond ash up to 20 % results in the reduction of shrinkage of concrete up to 22 %, and the results for the simultaneous replacement of cement with fly ash and sand with pond ash show a reduction of shrinkage of concrete up to 62 % as compared with the shrinkage of control concrete. Shrinkage strains for all 27 mixes have been determined by using different shrinkage models as well as a laboratory test. It is found that the shrinkage strain found from the ACI model matches with shrinkage strain determined from laboratory tests in a better way as compared with other models. Further, the ACI model has been modified to determine the shrinkage strain of concrete, prepared from supplementary cementitious materials.

Examination of mercury contamination from a recent coal ash spill into the Dan River, North Carolina, United States

Coal ash spills occasionally occur due to the accidental failure of surface impoundments, and toxic metal-laden ash can pose a serious health threat to adjacent aquatic ecosystems. Here, we performed an investigation into longitudinal variations of mercury (Hg) contamination in the Dan River (North Carolina, United States) about 17 and 29 months after a February 2014 coal ash spill incident, in which the reported Hg concentrations in the spilled coal ash (210 ng/g) were 1–2 orders of magnitude higher than the river sediments (2–61 ng/g). We examined total Hg (THg) and methyl Hg (MeHg) in sediments from 0 to 65 km downstream of the spill, and found that most of the variations of THg and MeHg in surface sediments (0–16 cm) could be well accounted by the organic matter content and appeared to be not contaminated by Hg derived from coal ash. In examining MeHg bioaccumulation in invertebrates (aquatic and riparian) and fish in the Dan River and fish in a reservoir downstream of Dan River, we found no evidence of elevated MeHg bioaccumulation due to the 2014 coal ash spill. Thus, we concluded that Hg contamination from the coal ash spill is largely absent in the Dan River for both surface sediments and biota within the first three years of spill (until 2017), even though the majority of coal ash may be buried deeper in the sediment in the river channel and/or the downstream reservoir. Alternatively, the Hg associated with the coal ash is largely not bioavailable for extensive microbial Hg methylation. The findings provide useful insights into remediation strategies for this incident and other coal ash spills.

Effective remediation strategies for ash dam sites in coal power plants

Pond ash is one of the main residual wastes from coal combustion. In coal power plants, the pond ash is usually mixed with seawater and stored as stockpiles, commonly known as ash dams. Once the ash dam ‘dries out’, the particles scatter with the wind, giving rise to various health issues. This research study aims to identify effective strategies for remediating the ash dam sites of coal power plants. Initially, the researchers conducted a literature review and expert interviews to identify strategies for remediation. The four alternatives are using (a) a sprinkler system, (b) Nu-Rock technology, (c) silicone extraction technology and (d) tree-planting technology. To validate the expert interview findings, this research quantified all the costs and benefits of the Port Augusta power plant in Australia as a case study. Silicone extraction technology and Nu-Rock technology create up to AU$20 million worth (AU$1 = US$0.718) of jobs within the area. Based on the analysis, it is identified that the Nu-Rock technology, silicone extraction process and plant regeneration alternatives are effective in ash dam remediation. The sprinkler system is a quick and temporary fix to ash dams until a permanent solution is introduced.

Use and Cost Comparison of Pond Ash with Fly Ash for Bricks Casting

Use and Cost Comparison of Pond Ash with Fly Ash for Bricks Casting

Structural performance of exterior beam-column joint using biochar impregnated pond ash concrete

RC Structures when exposed to seismic waves Beam-Column joints are an important part of the construction and play a significant role in the overall behavior. The most significant explanation behind the failure and abrupt breakdown during the seismic tremors is the insufficient provision of shear reinforcement in joints RC Structures. In reinforced concrete frames beam-column joint is the critical zone that should be designed to provide sufficient deformation capacity and ultimate strength. More vulnerable failures of joints around the exterior border of the structure occur than interior joints. In the static load analysis, the priority is strength and ductility So, in ordinary structures joints are designed by considering strength to resist wind and gravity loads. Experimental research is the most significant way to know the parameters which influence both joint performance and those that should be improved to upgrade joint performance. In the present study, two Specimens of Beam-Column joints were prepared one is with conventional concrete and other with concrete using 5% binder replaced with Biochar and 20% fine aggregate replaced with pond ash and the test results showed that the energy absorption and ductility were increased but stiffness was reduced in pond ash concrete when compared to conventional concrete and there is no much difference in deflections within yield stage but deflections were reduced in Ultimate stage in pond ash concrete compared to traditional.

An Investigation on Pozzolanicity of Mechanically Activated Pond Ash

Pond ash (PA) is one of the major industrial solid wastes from thermal power plants. In the present study, PA of different storage durations, i.e. freshly ponded, two year ponded and Six-year ponded ash were collected from Bellary Thermal Plant (BTP). All three kinds of PA were mechanically activated by grinding in Industrial Hammer Mill. Unprocessed Pond Ash (UPA) and Ground Pond Ash (GPA) were characterised for Particle Size Distribution (PSD) by Laser-diffraction analyser. Mineralogical and Morphological characteristics were analysed through X-ray Diffraction and Electron Microscopic studies. Chemical composition of PA was analysed. The pozzolanicity of PA and other Supplementary Cementitious Materials (SCM) was determined and compared by conducting Lime reactivity test. XRD patterns and Chemical analysis clearly indicate the presence of relatively more amorphous phases in a fresh batch of PA compared to the one which is ponded for a longer duration. Lime reactivity strength (LRS) of UPA was far behind the LRS of commonly used SCM’s. Mechanical activation of PA improved the LRS from 0.57 MPa to 2.41 MPa. The results suggest the possibility of enhancing the reactivity of PA with early use and more efficient grinding process, thus add value to PA for its use in concrete.

Strength Characteristics of Pond Ash – Hydrated Lime Admixture Treated Peat Soil

Peat soil is identified as unsuitable soil to support the structure’s foundation in original condition because it has the characteristics that make it fail when the excessive settlement occurred. It will give the effect of the building conditions because the substructure foundation building not safe to use for a long immersion period. Therefore, this study is to increase the strength of peat soil characteristics in an effective way using a low-cost budget. Each variant of 3, 6 and 9% of hydrated lime (HL) were mixed with 5% of pond ash (PA), at which PA is constant. Meanwhile, each variant of the 10 and 15% of PA was mixed with 3% of HL and tested in different soaking time (0, 3 and 7 days). The strength of the sample increases when the percentage of PA and HL increase during soaking time. 15% of PA sample shows the strength increased to the range of 16% at a 7 - day soaking time compares to the natural peat soil. Meanwhile, the 9% of HL sample also shows the strength was achieved in the range of 32% in 7-day soaking time. It was analyzed that the PA and HL addition increase the strength of original peat soil.

Compressive Strength of PPC Based Quaternary Blended Concrete

Production of sewage sludge is increasing day by day all over the world. By disposing of the sewage sludge the environmental issues take place in the society. Hence the research for replacement of cement using sewage sludge ash is essential to reduce the use of natural resources. Certainly as pond ash also coal ash as waste which compresses of bottom ash and fly ash. They contain the major chemical components which cement contain. So the major aim in this research study is to the best use of Biochar and pond ash in concrete. Concrete M20 specimens are prepared according to IS10262-2019 and by replacing cement with 5% Biochar and sand with 2-30% of pond ash by varying percentages in steps of 2 and the compressive strength was determined finally observed that 20% replacement of pond ash and 5% Biochar is giving the optimum value of compressive strength.

Demarcating antioxidant response against aluminum induced oxidative stress in Westiellopsis prolifica Janet 1941

Aluminum metal pollution is considered as a primary limiting factor that reduced crop yield in South Asian subtropical country like India. In national context, Odisha contributes around more than 40% of total ore availability. Moreover, industrial mining and smelting aid are major concern for aluminum metal toxicity in territorial vicinity affecting the soil fertility, ecosystem and human health through food chain. The aluminum metal accumulation limits the soil fertility by antagonistic regulation of photosynthetic and nitrogen fixing microbiota. The increasing concern regarding aluminum pollution enterprise critical investigations for their bioremediation in contamination sites. In this notion, the current study was hypothesized to decrypt the rate limiting factors, their explicit mode of action and intracellular detoxification in a cyanobacterium, i.e., Westiellopsis prolifica isolated from ash pond of NALCO (National Aluminum Company Limited), Angul, Odisha. In the experimental setup, treatment with different concentrations of AlCl3 (0–0.1 mM) was marked a decline in the growth of the strain due to the adverse regulation of photosynthetic pigments. However, the enforcement of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), guaiacol peroxidase (GPX) and glutathione reductase (GR) was critical for sustaining strain viability under oxidative imbalance. The observation of an increase in the antioxidant enzyme and MDA content was evident to sustain strain viability under such oxidative imbalance. The outcome of the anticipated study was apparent to demonstrate a colossal interlink between Al mediated induction of oxidative stress and their cellular detoxification via intracellular antioxidant enzymes and removal of H2O2 accumulation in cyanobacterium, W. prolifica. Statement of novelty Aluminum metal toxicity renders growth of Westiellopsis prolifica via affecting photosynthesis associated pigments. Westiellopsis prolifica deploys antioxidant defense enzymes to combat against aluminum mediated oxidative upset. Intracellular antioxidant enzymes provoke cellular survival of Westiellopsis prolifica under excessive uptake of aluminum in contaminated habitats.

Characterization of cement stabilized pond ash using FTIR spectroscopy

Pond ash is a mixture of fly ash and bottom ash obtained from thermal power plants. It has pozzolanic properties and is commonly treated with cement to impart cohesion and improve strength. The increase in strength gain in cemented pond ash is attributed to the hydration of cement and pozzolanic reactions due to silica present in the pond ash. Unconfined Compressive Strength (UCS) test is commonly used to determine the dosage of cement. While the strength gain is addressed by this test, the interaction mechanisms and the resulting compounds that are responsible for strength gain in such systems have not been identified at this point in time. In this study, an attempt is made to understand the interaction mechanisms between cement and pond ash by quantifying the influence of the dosage of cement, curing period, and curing temperature. FTIR spectroscopy is used for this purpose. Five dosages of cement (2, 4, 6, 8, and 24%), three variations in curing period (7, 14, and 28 days) and two different curing temperatures (27 °C and 50 °C) were adopted. Results showed that pond ash, used in this study, did not undergo any hydration reaction due to its low calcium content. In cemented pond ash, the hydration products formed in cement (Ca(OH)2) triggered pozzolanic reactions with silica present in pond ash to further form C-S-H, which is responsible for increased strength gain. The C-S-H formation did not vary linearly with cement content/curing period/curing temperature due to the pozzolanic reactions and the magnitude of influence exerted by each of these parameters depended on the other two parameters.

Site Characterization of Existing and Abandoned Coal Ash Ponds Using Shear-Wave Velocity from Multichannel Analysis of Surface Waves

AbstractCoal ash ponds or lagoons are surface impoundments constructed to store the unused coal ash generated from thermal power plants. In India, by the end of 2020 nearly 82,200 ha of land will b...

Development of Self Curing Geopolymer Concrete Incorporating Expanded Polystyrene, Recycled Coarse Aggregate and Rubber Crumbs

Sustainable building production includes the effective usage of natural materials by the processing of waste materials. The present work aims to use different waste materials, such as fly ash, industrial waste pond ash, rubber crumbs from rubber tires, recycled coarse aggregate from building waste. In doing so, the goal of reducing building costs will be achieved and can help to solve the issues connected with its disposal, particularly the environmental concerns of the area. Throughout this project, Rubber Crumbs (RC) and Recycled Coarse Aggregate (RCA) were partly substituted instead of coarse aggregate with a percentage of 10, 15, 20, and 5, 10, 15, which were found to improve the flexural strength of concrete. Such products may also be used for renewable building purposes.

Volume change behaviour of an expansive clay blended with lime and pond ash – controlling swell

This paper presents the influence of lime content on free swell index (FSI) of an expansive clay powder passing through a 425 µm sieve and on some significant swell-compressibility characteristics of oven-dry, expansive clay with grains of a size <4.75 mm. One-dimensional swell-consolidation tests were conducted on the expansive clay passing through a 4.75 mm sieve to which lime powder (CaOH 2 ) was added at 0, 1, 2 and 4% by dry weight of the clay. Swell potential, swelling pressure, coefficient of compressibility ( a v ), compression index ( C c ) and linear shrinkage ( LS ) were evaluated. While a v , C c and LS decreased significantly with increasing lime content, swelling pressure increased. Heave and swell potential also decreased with increasing lime content but only up to 2% and were found to have increased at 4% lime content. The paper also compares the swell-compressibility behaviour of 2% lime-blended expansive clay lumps and powders. Heave and swell potential were higher for clay powder than for clay lumps at 2% lime. However, swelling pressure ( p s ) was found to be more for clay lumps than clay powder. Furthermore, the paper also presents the variation of FSI and swell-compressibility characteristics of another expansive clay powder (of different properties) blended with pond ash contents of 0, 5, 10, 15 and 20%. One-dimensional swell-consolidation tests were conducted on clay–pond ash blends in an oedometer. Swell potential and swelling pressure decreased up to 15% of pond ash content and increased thereafter, when pond ash content was increased to 20%. FSI of the ash-blended clay specimens was also determined. FSI continuously decreased with increase in pond ash content.