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The construction industry is experiencing an increasing demand for sustainable alternative materials. There is huge scope for converting the industrial wastes as partial or complete substitution of cementitious materials and fine aggregates. This study focuses on exploring the performance of different industrial waste materials as possible substitutes for flowable fill or controlled low-strength materials (CLSM). The most commonly used waste materials are found to be bottom ash, pond ash, steel slag, alum sludge, waste glass powder, red mud, cement kiln dust, copper slag, treated oil sand waste, and waste oyster shells. In order to verify their  suitability compaas potential CLSM, the plastic properties (flowability, hardening time, segregation, bleeding, and density), hardened or in situ properties (unconfined compressive strength, California bearing ratio, and ultrasonic pulse velocity), durability properties (permeability and freezing-thawing effects), and microstructural properties (X-ray diffraction and scanning electron microscopy) are compared. It is observed that the addition of different industrial wastes could satisfy the provision of CLSM as per ACI standards. There is immense scope for improvising the present utilization through functional optimization as well as investigating the potential of many unused waste materials which are locally available in bulk., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Expansive clays feature high compressibility and large swelling-shrinkage potential, which may cause significant damage to the infrastructures, including pavements. This study investigates the potential use of industrial waste ash generated from municipal solid waste incineration (MSWI) as a more sustainable treatment method to treat expansive soils compared to the use of conventional coal fly ash. A series of tests was conducted to study the mechanical, durability, and environmental performance of the MSWI fly ash in comparison with the coal fly ash. The study reveals that the compressive strength and resilient modulus of 20% MSWI fly ash treated sample increased to 0.86 MPa and 213 MPa respectively, depicting an increase of 150% and 240% of the control clay specimen. Results also indicate that MSWI treated expansive clay shows better performance during the soaked California bearing ratio (CBR) testings, moisture susceptibility and cyclic wetting–drying tests compared to coal fly ash treated samples. Microlevel investigations reveal that the influence of cation exchange is more decisive in the MSWI-treated clays due to the presence of higher Ca2+ ions, during the early stages, and the influence of hydration is stronger at the later stage of stabilisation. X-ray diffraction (XRD) results show that gismondine, albite, calcite, portlandite, andradite, and ettringite are the main crystalline phases formed during the stabilization. Heavy metal concentrations after the stabilisation are within the allowable limit defined by state regulations. Applying MSWI fly ash as a ground treatment for expansive clays can reduce the consumption of natural resources, promoting a "zero landfill" policy. [ABSTRACT FROM AUTHOR]

Due to industrialization, soil heavy metal pollution is a growing concern, with humic substances (HS) playing a pivotal role in soil passivation. To address the long duration of the compost humification problem, coal fly ash (CFA) in situ catalyzes the rapid pyrolysis of the cotton stalk (CS) to produce HS to address Cd passivation. Results indicate that the highest yield of humic acid (HA) (8.42%) and fulvic acid (FA) (1.36%) is obtained when the CS to CFA mass ratio is 1:0.5, at 275 ℃ for 120 min. Further study reveals that CFA catalysis CS humification, through the creation of alkaline pyrolysis conditions, Fe2O3 can stimulate the protein and the decomposition of hemicellulose in CS, and then, through the Maillard and Sugar-amine condensation reaction synthesis HA and FA. Applying HS-CS&CFA in Cd-contaminated soil demonstrates a 26.69% reduction in exchangeable Cd within 30 days by chemical complexation. Excellent maize growth effects and environmental benefits of HS products are the prerequisites for subsequent engineering applications. Similar industrial solid wastes, such as steel slag and red mud, rich in Fe2O3, can be explored to identify their catalytic humification effect. It could provide a novel and effective way for industrial solid wastes to be recycled for biomass humification and widely applied in remediating Cd-contaminated agricultural soil. [ABSTRACT FROM AUTHOR]

CO2 mineralization plays a critical role in the storage and utilization of CO2. Coal fly ash (CFA) and red mud (RM) are widely utilized as CO2 mineralizers. However, the inert calcium species in CFA limit its carbonation capacity, meanwhile the substantial Ca2+ releasing of RM is hindered by a covering layer of calcium carbonate. In this study, CO2 mineralization in a composite system of CFA and RM was investigated to enhance the carbonation capacity. Multiple analyzers were employed to characterize the raw materials and resulting mineralization products. The results demonstrated that a synergistic effect existed in the composite system of CFA and RM, resulting in improving CO2 mineralization rate and efficiency. The produced calcium carbonate was ectopically attached the surface of CFA in the composite system, thus slowing down its coverage on the surface of RM. This phenomenon facilitated further releasing Ca2+ from the internal RM, thereby enhancing CO2 mineralization efficiency. Meanwhile, the inclusion of RM significantly improved the alkalinity of the composite system, which not only promoted the dissolution of Ca2+ of the inert CaSO4(H2O)2 in CFA, but also accelerated CO2 mineralization rate. The investigation would be beneficial to CO2 mineralization using industrial solid wastes. [ABSTRACT FROM AUTHOR]

The search for a sustainable society makes necessary the reuse of residues contributing to the producing high-value product. Producing new materials with high-added value increases technological development and builds up new applications. The present study aimed to use residue from the alumina industry and coal ash generated in thermal plants in energy production to synthesize zeolite for wastewater treatment to remove Cs and Pb. Two types of nanomaterials were synthesized: zeolite 4A (ZEA) and zeolite sodalite (ZSD). The Cs adsorption efficiency achieved 73% and 9.4% for ZEA and ZSD, respectively, fitting better for Lineweaver-Burk isotherm and both zeolites removed 100% of Pb from synthetic solutions. Results here reported may be used to design novel wastewater treatment systems from nuclear plants and other industrial processes. The present study can contribute to achieving Sustainable Development Goals 9, 11, and 12. Cs removal achieved 73% for ZEA fitting better for Lineweaver-Burk isotherm Nanozeolites were obtained from alumina industry residue Nanomaterials were capable to remove elements present in nuclear wastewater Removal of Pb achieved 100% by both zeolites [ABSTRACT FROM AUTHOR]

To solve the environmental pollution problem caused by the accumulation of bulk industrial solid wastes, the current research state on the preparation of mullite materials from industrial solid wastes was summarized. The preparation of mullite materials from alumina-rich and silica-rich industrial solid wastes was analyzed and summarized. The main problems encountered were pointed out, and the future develop-ment direction was looked forward. [ABSTRACT FROM AUTHOR]

AMD (acid mine drainage) with low pH and high content of heavy metals is a serious environmental problem in mining activities. Proper AMD management is crucial to ensure compliance with the standards of environmental quality before allowing the flow to the public water system. The objective of this study was to assess the efficacy of increasing pH and decreasing Fe alongside the concentrations of Mn in AMD with the addition of coal fly ash (CFA) and empty fruit bunch of oil palm (EFBOP). A total of four treatments, namely: (1) control (soil without treatment), (2) soil + EFBOP, (3) soil + CFA, and (4) soil + EFBOP + CFA were tested for the ability to improve AMD quality in a batch reactor experiment for 90 days. Weekly observations were carried out for pH, Fe, and Mn concentrations during the experiment, where part of AMD in the reactor was drained and replaced with fresh ones. The results showed that single treatment of EFBOP or CFA caused a pH increase at 2.8 to 5.1-5.4 and 6.3-6.8, respectively. Furthermore, a greater increase occurred from 2.8 to 7.0-7.8 when EFBOP was combined with CFA application. This combination also showed a greater reduction in the concentrations of Fe and Mn compared to the single treatment of EFBOP or CFA. The increase in pH and decrease in Fe alongside the Mn concentrations began in the 3rd week, and this effect was stable during the 90 days of the experiment. The results underscore the potential of EFBOP and CFA as agricultural and industrial wastes in long-term AMD management. [ABSTRACT FROM AUTHOR]

The utilization of coal ashes to replace different natural aggregates is a standard procedure adopted nowadays for different civil engineering applications. Reutilization of these industrial waste products generated from the thermal power plants for civil engineering applications is beneficial to society and the environment in various ways. Thus, this research paper deals with the studies done to analyse the effectiveness of using pond ash for controlled low strength materials (CLSM) production. Further, stresses and strains developed on the buried pipelines where CLSM was used instead of the standard aggregate-based bedding layer were also analysed. A comparative study of the stresses and strains developed on the buried pipelines was evaluated using PLAXIS 2D software. The results from the studies showed that the plastic and in-service properties obtained for the pond ash-based CLSM mixtures are equivalent to regular aggregates used in bedding layer applications. Further, the analysis of stresses and strains developed on the buried pipelines using the Plaxis 2D numerical tool showed that the stresses and strains developed on CLSM as bedding layer-based pipelines performed better than the normal bedding layers. Thus, pond ash-based CLSM mixtures can be used as an alternative to normal aggregates as the stresses and strains developed were found to be lesser than that of normal aggregatebased bedding layers. [ABSTRACT FROM AUTHOR]

Complex dyes have an adverse impact on the environment since they have a high aqueous solubility and are very challenging to be removed using conventional approaches. A series of batch tests were performed to determine the optimum parameters for the direct blue 78 dye adsorption process as a function of chemically treated coal fly ash (TCFA) Effect of fly ash dose, contact time and dye initial concentration were studied using an industrial wastewater. A pilot plant, consisting of three stages; mixing, sedimentation and filtration was designed and implemented to investigate the ability of TCFA to remove COD, BOD5, TDS and TSS from textile wastewater under optimal conditions. A series of fly ash physico-chemical analysis including particles size analysis, zeta potential, XRD, EDX, BET, SEM and FTIR were investigated. The results showed that the particles size and zeta potential for raw coal fly ash were 1.2 µm and −20.70 mv. Chemical treatment process using hydrochloric acid resulted reducing the particles size of fly ash from 1.2 µm to 0.95 µm. Zeta potential value increased to + 7.20 mv. Batch adsorption process showed that the removal efficiency decreased as the primary dye concentration increased. It increased when fly ash loading and contact time increased. Dyes removal was achieved up to 99.7% using TCFA loading 3gL−1 for initial dye concentration10 mgL−1. Studies on equilibrium revealed that the equilibrium data was closely fitted to the Freundlich and Langmuir isotherm models. Kinetic study of adsorption process was studied in detial. Based on high correlation coefficient (R2 = 0.999), the results were followed pseudo second-order model. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA) is an anthropogenic industrial byproduct that is expected to increase exponentially to fulfill the needs of energy using coal and agro-waste as a cheap fuel. The disposal of this classified human carcinogen is a major concern in developing and underdeveloped economies due to lack of resources. Recycling and value addition of industrial waste, coherence with sustainable development goals is a viable solution. Zeolitization of coal fly ash is an ideal approach for recycling this waste into superior products to be used in a variety of industrial applications. This study was aimed to recycle CFA to useful zeolites using ultrasound assisted hydrothermal process. Sesamum indicum plant stems based fly ash (rFA) was found to belong to class “F" and has very low moisture and carbon contents. To investigate the morphology and elemental composition of rFA and UHSZ, SEM/ EDX was used along with XRD, FTIR and Raman spectroscopy which confirmed the existence of quartz, mullite and anhydrite. SEM/EDX results revealed the presence of Al, Si, S, K, Sb, Mg and Ta in raw ash. Adsorption studies of both rFA and synthesized zeolite(UHSZ) were conducted to determine the quintessential parameters of pH, time, initial dose of adsorbent for optimum results. Fabricated zeolites (2 g/100 mL) from raw fly ash removed 90–98% of chlorazol black E (DB38) from 100 mg/L solution within 40 min at pH ≈ 7. Both Langmuir and Freundlich isotherms gave best fit, which validated that the adsorption of DB38 to UHSZ was a blended process rather than a simple monolayer adsorption mechanism. Pseudo 1st-order and 2nd-order kinetic models were adopted to fit the obtained kinetic data. The pseudo 2nd-order kinetic model was found to be most related. [ABSTRACT FROM AUTHOR]

High-ash coal slime is difficult to utilise as a boiler fuel, and its accumulation results in environmental pollution. In this study, we describe a new method for the preparation of high-ash coal slime silica compound fertiliser (HASF) using CaO–KOH mixed hydrothermal method to optimize the utilization of this industrial waste and relieve the pressure on the fertiliser industry. The coal slime (D0) used in this study and its dry basis ash content by 1 mol/L and 4 mol/L sulfuric acid pre-activation (D1, D4) were greater than 85%. The effective silicon content of D0, D1, and D4 silica compound fertilisers reached 30.24%, 31.24%, and 17.35%, respectively, and the sums of effective silica-calcium-potassium oxides were 57.28%, 58.87%, and 48.16%, respectively, under the optimal reaction conditions of 230 °C, 15 h, and 1 mol/L KOH, which met the market requirements, as determined using single-factor experiments. We used XRD, FTIR, and SEM–EDS analysis techniques to demonstrate that tobermorite and leucite were the main mineral phases of the compound fertiliser, and activated coal slime D4, which contains only quartz single crystals, required more demanding reaction conditions in the synthesis reaction. Subsequently, the cumulative release pattern of HASF silica was well described by the power function equation via repeated extraction and dissolution experiments, with the dissolution rate following D4 > D1 ≈ D0. Furthermore, 4 mol/L sulfuric acid pre-activation resulted in the enrichment of HASF combined with organic matter and increased the slow-release rate of HASF silica. Thus, the synthesized HASF could have potential application prospects in soil improvement and fertilisation. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería (0121-750X) is the property of Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main aim of this study was to develop and monitor an effective and cost-efficient industrial wastewater treatment system that utilizes sand, fly ash, and hearth ash. The latter two are potentially available and inexpensive industrial waste materials that can be used for filtration. The infiltration percolation method was utilized in a vertical cylindrical column to filter the raw wastewater from a detergent manufacturing plant. The main parameters analyzed before and after treatment included suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and pH. The system successfully achieved significant reductions, including 89% in COD, 73% in BOD5, and 54% in suspended solids (SS), along with a 66% to 99% reduction in heavy metals. The COD/BOD5 rejection ratio decreased from above 4.24 before treatment to below 1.73 after treatment. Furthermore, impedance measurements were carried out across the frequency range of 100 to 1 MHz. The analysis of complex conductivity spectra revealed two Cole–Cole relaxation behaviors, and an equivalent circuit was developed to extract the primary parameters and further investigate both relaxation processes. The results of the electrical parameters deduced from the impedance spectra demonstrated a strong correlation with the parameters obtained through conventional methods. [ABSTRACT FROM AUTHOR]

Disposal of dyes wastewater into aquatic streams is considered as a major challenge due to its effect on water ecosystem. Direct dyes have a complex aromatic structure. Therefore, it is difficult to separate them from industrial wastewater. Conversely, fly ash is a main by-product pollutant generated from coal burning to fulfill energy requirements. In this study, thermochemical treatment process was applied to coal fly ash (CFA) in order to increase its surface area, improve its pore's structure and enhancing its adsorption capacity for direct blue 78 dye (DB78) removal. The treated coal fly ash (TCFA) was characterized by physicochemical analyses such as XRD, XRF, TGA, SEM, FTIR, surface area (SBET) and particles size analysis. Batch experiments were conducted to analyze the adsorption behavior for TCFA and to examine the DB78 dye removal efficiency. The physicochemical analysis results indicated that a higher increase in CFA surface area from 9.6 to 60.4 m2g−1 was obtained due to the modification process. The maximum removal efficiency using TCFA was 99.7% for initial dye concentration 10 mg/L and TCFA dose 2 g/L. The adsorption isotherm was studied by Langmuir and Freundlich model using different dye concentrations. The results showed that equilibrium data followed closely Langmuir isotherm model (R2 = 0.99) indicating monolayer and homogeneous adsorption process. [ABSTRACT FROM AUTHOR]

Poland is a country where the commercial power industry mainly uses coal to produce energy. As a result of energy production processes, by-products of combustion are generated, primarily fly ashes. In Poland, these are mostly obtained from conventional coal combustion boilers. Fly ashes from coal combustion account for 1.2% of all industrial waste generated in Poland. In addition, fly ashes are produced by fluidized-bed boilers. These are classified as a mixture of fly ashes and solid calcium-based reaction waste from flue-gas desulphurization, and constitute almost 2% of Polish industrial waste. This paper describes the amounts of fly ashes generated in Poland and considers activities related to their recovery and disposal. The high recovery levels of fly ashes (about 90%) and fluidized ashes (about 98%) mean that these waste products can also be considered anthropogenic raw materials. The use of these materials in the cement industry is an example of industrial symbiosis. Such usage benefits not only the economy but also the environment and, therefore, society as a whole. To describe the use of recovered fly ashes in cement plants, the authors use the anthropogenicity index, which characterizes the level of technological advancement and the substitutability of primary raw materials for secondary raw materials. [ABSTRACT FROM AUTHOR]

Currently, there is an increasing industrial demand for rare earth elements (REE) as these elements are now integral to the manufacture of many carbon-neutral technologies. The depleting REE ores and increasing mining costs are prompting us to consider alternative sources for these valuable metals, particularly from waste streams. Although REE concentrations in most of the alternative resources are lower than current REE ores, some sources including marine sediments, coal ash, and industrial wastes, such as red mud, are emerging as promising with significant concentrations of REE. This review focuses on the alternative resources for REE, such as ocean bottom sediments, continental shelf sediments, river sediments, stream sediments, lake sediments, phosphorite deposits, industrial waste products, such as red mud and phosphogypsum, coal, coal fly ash and related materials, waste rock sources from old and closed mines, acid mine drainage, and recycling of e-waste. Possible future Moon exploration and mining for REE and other valuable minerals are also discussed. It is evident that REE extractions from both primary and secondary ores alone are not adequate to meet the current demand, and sustainable REE recovery from the alternative resources described here is also necessary to meet the growing REE demand. An attempt is made to identify the potential of these alternative resources and sustainability challenges, benefits, and possible environmental hazards to meet the growing challenges of reaching the future REE requirements. [ABSTRACT FROM AUTHOR]

Progressively and projected integration of rare earth metals (REMs) in modern technologies, especially in the clean energy, consumer electronics, aerospace, automotive, and defense sectors, place REMs as critical raw materials in the supply chain and strategic metal from the fourth industrial revolution perspective. Current REM production from the primary mineral resources in the supply chain versus industrial demand is at a bottleneck. Alternatively, REM-bearing anthropogenic wastes are pertinent and potent to addressing the critical supply chain bottleneck. Although secondary REM resources are prudent to address the critical supply chain bottleneck, the absence of effective and efficient technologies to recover these REMs from anthropogenic waste imposes challenges and provides opportunities. Hence, this review analyses and discusses the significance of anthropogenic wastes for REM recovery, the status of recycling technologies for sustainable valorization of REMs, challenges, and opportunities. The current review covers the potential quantitative REM wealth locked in various anthropogenic waste like (i) spent rare earth permanent magnets, (ii) spent batteries, (iii) spent tri-band REM phosphors, (iv) bauxite industry residue red mud, (v) blast furnace slag and (v) coal mines, and coal byproducts and status of valorization technologies for circularizing the REMs. In industrial waste like red mud, steelmaking slag, blast furnace slag, and coal fly ash typically 109,000, 2000, 39,000, and 354,000 tons of REM get scrapped, respectively, in a conservative estimation. In the years 2020 and 2021, respectively, 240,000 and 280,000 tons of REM were produced by mine production in contrast to 504,000 tons of REM that were scrapped with REM-bearing industrial waste. This review revealed that total REM currently getting scrapped with anthropogenic waste versus projected REM demand for the years 2022, 2023, 2024, and 2025 could be standing at 2.66, 2.51, 2.37, and 2.23, respectively. Our investigation revealed that efficient recovery of REMs from anthropogenic waste is significant and promising but associated with challenges like lack of industrial-scale valorization process, lack of a clear strategy, road map, policy, effort, funding, and diversified research. [ABSTRACT FROM AUTHOR]

Copyright of Romanian Journal of Civil Engineering / Revista Română de Inginerie Civilă is the property of Matrix Rom and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water pollution has become one of the most acute environmental problems. One of the pollutants coming to water bodies from industries are dyes, which are harmful to human health, living organisms, and the esthetic appearance of water. Most dyes are toxic, carcinogenic, rarely biodegradable, and highly soluble in water. Therefore, industrial wastewater treatment has become important. Adsorption technique of removal of dyes from water is simple, efficient, and inexpensive as compared to other techniques. Adsorption efficiency depends on the type and surface area of adsorbents. Iron-rich coal fly ash (IRCFA)–Polydopamine (PDA)@ Silver (Ag) nanocomposite was prepared by separating the iron-rich part (IRCFA) from coal fly ash and coated with polydopamine. IRCFA was mixed with 10 mM tris buffer solution containing 1 g dopamine. The prepared IRCFA-PDA was added to an aqueous solution of silver nitrate, heated at 60 °C, and then 30 mL of flower waste extract was added to this solution. Solid IRCFA-PDA@Ag was obtained, and the prepared nanocomposite was used for the removal of methylene blue (MB) dye from water. The nanocomposite used was prepared by a cost-effective method and has high reusability, separability, and fast regeneration ability. The mechanism of removal of MB dye has been discussed in detail. [ABSTRACT FROM AUTHOR]

To reduce the filling cost of high-water backfilling material (HWBM) in mining backfill and improve the recycling utilization of the industrial waste such as the coal fly ash. The ultra-fine fly ash (UFA) was added to the HWBM as a partial replacement in this work. Therefore, a series of experiments were performed to investigate the effect of UFA on the mechanical properties of the HWBM at the different curing conditions, then the hydration mechanism of the HWBM blended with UFA was analyzed by XRD and SEM method. The result indicates that the strength of the HWBM decreased with the increasing of UFA dosages, but the addition of UFA can improve the residual strength of the initial HWBM. Additionally, when the HWBM was cured at the laboratory air condition, its carbonation process was restrained obviously as the UFA dosages were less than 15% at the ages of 28 days, which indicates the UFA can improve the weathering resistance of the HWBM with the curing ages increasing effectively. The XRD and SEM results also shows that the degree of crystallinity of the HWBM increased when UFA dosages were less than 15% effectively, while there were few obvious changes on types of hydration products. It indicates that the main affects of UFA on the performance of HWBM is filler and dilution, which reduced the contact area between hydration products of HWBM and CO2 in the air, further improved the carbonation resistance of HWBM. [ABSTRACT FROM AUTHOR]

Calcium looping (CaL) process relying on CaO as high-temperature CO 2 sorbents is a prospective alternative technology for simultaneously cyclic CO 2 capture and thermochemical energy storage. However, the cyclic stability and the energy storage density of the CaO-based sorbents decay drastically over repeated carbonation-calcination cycles. Herein, we yielded CaO-based sorbents derived from all industrial solid wastes with carbide slag (CS) as precursor and coal fly ash (CFA) as stabilizer featuring superior carbonation characteristics, stable CO 2 cyclic uptake and high thermochemical energy storage density over multiple operation cycles. The optimal sorbent (CCS–H-G-CFA-D) exhibited a high initial CO 2 uptake of 0.38 g CO2 /g sorbent , superior cyclic stability with an average decay rate of 1.05% per cycle and remarkably stable energy storage density of 1375 kJ/kg, retaining 89.5% after 10 repeated cycles. Thereby, the simultaneously enhanced cyclic CO 2 capture and thermochemical energy storage are attributed to adding CFA stabilizers in CS-derived CaO-based sorbents, forming stable skeleton to alleviate sintering, improving the uniform mixing degree between sorbent particles and promoting the carbonation reaction via synergistic effect. This simple and eco-friendly approach of cost-effective sorbents totally derived from industrial solid wastes provides a new avenue for large-scale practical CO 2 capture and energy storage processes. Coal fly ash (CFA)-stabilized carbide slag-derived CaO-based sorbents feature superior carbonation characteristics, stable CO 2 cyclic uptake and high thermochemical energy storage density over multiple reversible operation cycles. [Display omitted] • A process coupled calcium looping and thermochemical energy storage is proposed. • Facile cost-effective strategy to synthesize all-solid-waste-derived CaO-based sorbent. • Modified carbide slag with coal fly ash is employed in coupled process. • The optimal sorbent retains 89.5% initial capacity with stable energy storage density. • New-formed solid solutions and uniform doping enhance stability by isolating CaO grains. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zeolites are promising materials for the uptake of toxic pollutants from water. • The structure of zeolites has been discussed in this review. • The up-to-date advancement in zeolite-based materials for dye removal is presented. • The scope of future research is also provided. • The mechanism of adsorption and photodegradation is shown. One of the main causes of environmental contamination is the textile sector. Approximately 20 % of global industrial water pollution is caused by the textile dye industries. Although many different kinds of pollutants exist in industrial wastewater, dyes are particularly relevant to this work. Dyes are the class of emerging pollutants that severely affect water quality. Secondly, coal-powered thermal power plants, in addition to their major share in air pollution, also produce a huge amount of coal fly ash (CFA), which adds to land pollution. Disposing of CFA and removing textile dyes from water has remained a challenging problem for the world. However, with the innovation of science and technology, thanks to the discovery of synthetic zeolites, which significantly helped reduce the pollution caused by industries and thermal power plants. The synthesis of zeolites from CFA solves the problem of its disposal; additionally, zeolites are proven to be excellent adsorbents and support for photocatalysts, which aided in removing dyes from wastewater. The present articles discuss the structure and synthesis of zeolites from CFA, along with their application as adsorbents and photocatalysts for water treatment. This review aims to present an overview of the latest advancements in synthesizing and utilizing zeolite-based nanocomposites as photocatalysts and adsorbents for removing dyes from wastewater. [ABSTRACT FROM AUTHOR]

Electrolytic manganese residue (EMR) is known for high concentrations of Mn2+, NH 4 +, and heavy metals. Failure to undergo benign treatment and landfill disposal would undeniably lead to negative impacts on the quality of the surrounding ecological environment. This study sought to mitigate the latent environmental risks associated with EMR using a cooperative solidification/stabilization (S/S) method involving coal fly ash (CFA). Leveraging leaching toxicity tests, the leaching behavior of pollutants in electrolytic manganese residue-based geopolymer materials (EMRGM) was determined. At the same time, mechanistic insights into S/S processes were explored utilizing characterization techniques such as XRF, XRD, FT-IR, SEM-EDS, and XPS. Those results confirmed significant reductions in the leaching toxicities of Mn2+ and NH 4 + to 4.64 μg/L and 0.99 mg/L, respectively, with all other heavy metal ions falling within the permissible limits set by relevant standards. Further analysis shows that most of NH 4 + volatilizes into the air as NH 3 , and a small part is fixed in the EMRGM in the form of struvite; in addition to being oxidized to MnOOH and MnO 2 , Mn2+ will also be adsorbed and wrapped by silicon-aluminum gel together with other heavy metal elements in the form of ions or precipitation. This research undeniably provides a solid theoretical foundation for the benign treatment and resourceful utilization of EMR and CFA, two prominent industrial solid wastes. [Display omitted] • The optimal formulation for preparing C-A-S-H gel using EMR and CFA is determined. • Leaching tests demonstrate the environmental friendliness of EMRGM. • The Mn2+ and NH 4 + S/S mechanisms have been analyzed and discussed. • Correlation analysis of test outcomes was conducted using the Spearman method. • Endorsement offered for the harmless and resourceful utilization of EMR and CFA. [ABSTRACT FROM AUTHOR]

• Rare earths are main source of revenue among coproducts of most secondary sources. • Different sources within each category shows large variability in contained value. • Industrial waste revenues are driven by scandium, electronic waste by neodymium. • Contained rare earth value increases as power law of total rare earth oxide content. Expanding use of rare earth elements (REEs) necessitates characterizing deposits. Challenges include variable REE concentrations (e.g., coal ash ranges from 267 to 843 ppm) and price volatility. For a range of sources, we estimate distributions in the REE value per tonne of material, by collecting multiple data points for each type and using mean-reversion price forecasting. The study covers primary ores (e.g., bastnaesite), industrial wastes (e.g., red mud) and consumer wastes (e.g., NiMH batteries). Electronic wastes have highest value, driven by neodymium, industrial waste value is driven by scandium. Variability exists within resource types, e.g., the value of Australian monazite > Bayan Obo bastnaesite > Malaysian monazite. Using a power-law relationship, the total REE value of a sources correlates well with its ore grade. These results inform investment decisions to develop primary and secondary sources by clarifying potential variability and providing a useful rule of thumb to estimate revenues. [Display omitted] [ABSTRACT FROM AUTHOR]

Increasing the percentage of recycling of various industrial waste is an important step towards caring for the environment. Coal ash is one of the most large-tonnage wastes, which is formed as a result of the operation of thermal power plants. The aim of this work is to develop a technology for the complex processing of coal ash. The tasks to achieve this aim are to develop a technology for the complex enrichment and separation of coal ash into components, with the possibility of their use in various applications, in particular: processing the aluminosilicate part as a pozzolanic additive to cement; carbon underburning for fuel briquettes; the iron-containing part for metallurgy and fertilizers. Complex enrichment and separation into components of coal ash were carried out according to the author's technology, which includes six stages: disintegration, flotation, two-stage magnetic separation, grinding, and drying. The aluminosilicate component has a fairly constant granulometric composition with a mode of 13.56 μm, a specific surface area of 1597.2 m2/kg, and a bulk density of 900 kg/m3. The compressive strength for seven and twenty-eight daily samples when Portland cement is replaced by 15% with an aluminosilicate additive, increases to 30–35%. According to the developed technology, high-calorie fuel briquettes are obtained from underburnt with a density of 1000–1200 kg/m3, a calorific value of 19.5–20 MJ/kg, and an ash content of 0.5–1.5%. The iron-containing component, recovered by two-stage magnetic separation, has the potential to be used in metallurgy as a coking additive, in particular for the production of iron and steel. In addition, an effective micro-fertilizer was obtained from the iron-containing component, which: is an excellent source of minerals; improves the quality of acidic soil; helps soil microorganisms decompose organic matter faster, turning it into elements available to plants; promotes rooting of seedlings; helps to more effectively deal with many pests and diseases. As a result, the complete utilization of coal ash in various applications has been achieved. [ABSTRACT FROM AUTHOR]

Geopolymer is an emerging material that is known to have excellent properties. Numerous applications of geopolymer have been reported in various studies, for example, in the construction and building sector, nuclear waste management, and wastewater treatment industry. It gains popularity in the wastewater treatment sector as it can effectively adsorb pollutants (e.g., heavy metals). However, the performance of this material varies depending on different factors such as the type of precursors, mix formulation, process conditions, etc. Moreover, optimal selection should also consider the potential environmental impact and safety to the general public before field application. The utilization of coal fly ash and other potential material was investigated to develop a pervious geopolymer. In this study, selection of optimized geopolymer mix for heavy metal removal using TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) and AHP (Analytic Hierarchy Process) with a spherical fuzzy approach was employed. An illustrative case study is presented for the proposed decision modeling technique in optimally selecting pervious geopolymer mix. [ABSTRACT FROM AUTHOR]

In this work, coal bottom ash was modified by alkaline fusion route in order to improve its pore properties and make it a potential adsorbent to remove crystal violet dye from aqueous medium. The solids were characterized and posteriorly subjected to kinetic, isotherm, and thermodynamic studies, as well as regenerated and reused for five adsorption tests. The alkaline fusion step resulted in the amorphization of material and generation of high surface area (102 m 2 g −1) and pore volume (0.180 cm 3 g−1), resulting in superior performance compared to the raw material. Kinetic and equilibrium studies showed that the adsorption process was better adjusted by the pseudo-second order and Langmuir models, respectively. The maximum adsorption capacity at equilibrium was 177. 37 mg g−1, with the adsorptive step occurring spontaneously and endothermically. The adsorbent maintained notable levels of dye removal after five consecutive cycles of thermal regeneration and reuse. Besides, the adsorbent was able to remove 64% of the colour of simulated industrial wastewater. Therefore, the alkaline fusion step proved to be a route capable of transforming the coal bottom ash into an adsorbent with improved textural and adsorptive properties. [ABSTRACT FROM AUTHOR]

Burnt clay bricks are one of the most important building units worldwide, are easy and cheap to make, and are readily available. However, the utilization of fertile clay in the production of burnt clay bricks is also one of the causes of environmental pollution because of the emission of greenhouse gases from industrial kilns during the large-scale burning process. Therefore, there is a need to develop a new class of building units (bricks) incorporating recycled industrial waste, leading toward sustainable construction by a reduction in the environmental overburden. This research aimed to explore the potential of untreated coal ash for the manufacturing of building units (coal ash unburnt bricks). Coal ash unburnt bricks were manufactured at an industrial brick plant by applying a pre-form pressure of 3 MPa and later curing them via water sprinkling in a control shed. Various proportions of coal ash (i.e., 30, 35, 40, 45, 50, and 55%) were employed to investigate the mechanical and durability-related properties of the resulting bricks, then they were compared with conventional burnt clay bricks. Compressive strength, flexural strength, an initial rate of water absorption, efflorescence, microstructural analysis via scanning electron microscopy, and cost analysis were conducted. The results of the compressive strength tests revealed that the compressive strength of coal ash unburnt brick decreased with an increase in the content of coal ash; however, up to a 45% proportion of coal ash, the minimum required compressive strength specified by ASTM C62 and local building codes was satisfied. Furthermore, bricks incorporating up to 45% of coal ash also satisfied the ASTM C62 requirements for water absorption. Coal ash unburnt bricks are lighter in weight owing to their porous developed microstructure. The cost analysis showed that the utilization of untreated, locally available coal ash in brick production leads us on the path toward more economical and sustainable building units. [ABSTRACT FROM AUTHOR]

Improving the dewatering performance of sludge is a necessary advancement for collaborative sludge disposal and energy-efficient utilization in power plants. Herein, the effects of temperature changes and the addition of drying accelerators derived from agricultural and industrial waste on the drying characteristics of sewage sludge (SS) were investigated from the perspectives of drying kinetics and micromorphology. According to the results, the drying time for sludge significantly showed a clear downward trend via medium–low temperature (160 °C) thermal drying, which subsequently reduced the energy input substantially. When the drying temperature was 160 °C, the ideal addition proportions of rice husk (RH), sludge ash (SA), and coal ash (CA) comprised 15%. The addition of SA prominently boosted the drying rate constant of the original sludge by 48%. Additionally, SEM images along with the spectral dimension obtained via fractal theory explicitly clearly demonstrated that SS + SA had more loose pore channels than other mixed samples. This provided a convenient approach to ensure the evaporation and migration of moisture and thereby shorten the drying time effectively. Consequently, the addition of sludge ash as a drying accelerator can promote the deep dewatering of sludge. [ABSTRACT FROM AUTHOR]

White mud is residue discharged during the acid method in the aluminum extraction process from coal fly ash, and this material is harmful to the environment. The implementation of an environmentally friendly and valuable way to use white mud is a key factor restricting the commercial application of the acid method in the fly ash alumina extraction technology. An analysis of white mud revealed the following: (1) it was highly enriched in SiO2 (70–80%) while concentrations of acid-soluble elements, such as Na, Al, and Fe, and some hazardous heavy metals, including Pb and Cr, were significantly lower than raw fly ash; (2) approximately 80% of SiO2 had relatively high reaction activity because of the foregoing Al-extraction treatment. Through an ingenious green chemical process, the complete conversion of white mud into silicon–calcium fertilizer (SCF) was achieved under very mild reaction conditions (approximately 100 °C and atmospheric pressure). Waste liquor was totally recycled, and no secondary solid waste was generated. The SCF had an available silicon content (ASC) of 35%, significantly higher than the commercial standard (20%). Converting them into soil conditioners or ecological remediation materials with the lowest possible energy consumption and secondary pollution may be the most promising approach for the future disposal of aluminosilicate industrial solid wastes. [ABSTRACT FROM AUTHOR]

High value-added NaHS zeolite was prepared using the microwave-assisted alkali fusion hydrothermal method from industrial solid waste coal fly ash as raw material without adding silicon and aluminum sources. The effect of mass ratio of alkali to coal fly ash, crystallization temperature, and crystallization time on the preparation of NaHS zeolite was investigated. The NaHS zeolite was characterized using XRD, SEM, BET, and FT-IR. The experimental results showed that the NaHS zeolite with complete crystal structure could be synthesized at m(sodium hydroxide):m(coal fly ash) = 2:1, crystallization temperature of 140°C, and crystallization time of 48 h. The prepared HS zeolite had high purity, complete crystal structure, and uniform grain size (2 μm). The NaHS zeolite was beneficial for CO2 adsorption properties with 110.9 cm3/g at 25°C. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA), an industrial by-product of high-temperature combustion of coal in coal-fired power plants, is one of the most complex and largest amounts of industrial solid wastes generated in China. It is widely recognized that CFA should be considered as a potential alumina resource to substitute bauxite. In this review, the features of high-alumina fly ash and aluminum recovery technologies are first described. Later, the merits and drawbacks of alumina extraction technologies in recovering more valuable materials are compared in terms of extraction mechanisms and equipment requirements. It is shown that "predesilicating-sodium carbonate (Na2CO3) activation-acid leaching" is currently a promising method in achieving multimetal synergistic extraction. Finally, the hydrochloric acid and sulfuric acid combination process is proposed as a sustainable development of the predesilicating-Na2CO3 activation-acid leaching process. The findings of this review provide theoretical guidance for novel developments and applications of aluminum extraction technologies. [ABSTRACT FROM AUTHOR]

Using synthetic zeolite from fly ash to treat high concentration phosphorus wastewater does not only improve the utilization of fly ash as solid waste but also reduce the environmental pressure caused by eutrophication. A synthetic zeolite was prepared from coal fly ash by one-step hydrothermal synthesis and applied for phosphorus adsorption from industrial wastewater (∼8,000 mg-P/L), and its adsorption characteristics and performance were studied. The results indicated that the product was a well-crystallized Na-P1 zeolite with typical morphology of plate- and rod-shaped crystals. Compared with the original fly ash, the specific surface area and average pore volume of the synthetic zeolite were nine and six times larger than the fly ash, reaching 43.817 m2/g and 0.122 cm3/g. The results from phosphorus adsorption onto the synthetic zeolite showed that the synthetic zeolite had good phosphorus adsorption properties. The adsorption process highly conformed to the pseudo-second-order kinetic model with the regression coefficient R2 of 0.998. Phosphorus adsorption on the synthetic zeolite was fitted to the Langmuir monolayer adsorption model, and the regression coefficient R2 was 0.989. The maximum phosphorus adsorption capacity was 84.4 mg-P/g-zeolite. [ABSTRACT FROM AUTHOR]

The combined processing of industrial wastes of titania-bearing slags with coal fly ash is an important part of the circular economy. In the present work, the effect of Al 2 O 3 on the 1400 °C liquidus isotherms of the perovskite, rutile and tridymite primary phase fields in the CaO–SiO 2 –TiO 2 –Al 2 O 3 system has been determined by employing a high-temperature equilibration-quenching technique, followed by X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry. Titanium was confirmed to be stable as TiO 2 in the present equilibria. The equilibrium solid phases of perovskite CaO·TiO 2 , rutile TiO 2 and tridymite SiO 2 were confirmed to be coexisting with the liquid oxide phase. The comparison of the addition of 0–15 wt% Al 2 O 3 was beneficial for expanding the primary phase field of perovskite to lower TiO 2 concentrations. Comparisons of the experimental 1400 °C isotherm with the predictions using FactSage and MTDATA databases confirmed some differences to the present experimental data, thus demonstrating the direction for updating the present thermodynamic titania-bearing oxide databases. [ABSTRACT FROM AUTHOR]

Coal fly ash, commonly produced from thermal power plants, is not only an industrial waste but an aluminum-rich resource that needs to be disposed of properly. This study aims to extract aluminum from coal fly ash using pressurized sulfuric acid (H2SO4) leaching and to investigate the dissolution mechanism during the leaching process. The effects of initial concentration of H2SO4, reaction temperature and time on the extraction of aluminum were investigated. Under optimized conditions (3 mol/l H2SO4, 220°C and 180 min), the extraction of aluminum reached 82.51%. It was found that mullite (3Al2O3·2SiO2) contained in coal fly ash was completely dissolved during the leaching, while the dissolution of silica-alumina glass beads was at a limited degree. The un-leached aluminum was found to be locked inside the glass beads which H2SO4 was unable to access. [ABSTRACT FROM AUTHOR]

There is a growing demand for the development of sustainable electrical energy generation devices with a high energy-to-price ratio. On the other hand, industrial waste, such as fly ash is a hazard to environmental pollution. However, here for the first time, water-based self-rechargeable batteries have been fabricated by using bio-waste (golden shower tree bark ash (TBA)), a rural pollutant (cow dung ash), and industrial pollutant (coal fly ash). The TBA-based battery, out of all three batteries, shows the highest open-circuit voltage of ∼1.48 V and a specific capacity of 183 mAhg−1. Further, the TBA based cell has retained ∼97% columbic efficiency even after 2000 cycles. It has been found that pH of TBA ash is the highest, i.e. ∼12 in presences of tap water and it is found that the TBA ash is composed of a large number of metal oxides. The materials present in the ash powder have generated oxides and hydroxides ions which have, in turn, caused the generation of the potential difference between the two electrodes. The fabricated devices are portable and can power up a large number of electronic gadgets, including light-emitting diodes (LEDs). It is envisioned that this work may open the door to the development of sustainable, environment-friendly, and low-cost bio-waste ash-based self-rechargeable energy devices in future. Environment friendly self-rechargeable water-based bio-waste ash battery. [Display omitted] • Fabrication of commercial electrolyte free, bio-waste based self-rechargeable batteries. • The TBA based battery shows the highest open-circuit voltage of ∼1.45 V. • The TBA-based cell shows the highest specific capacity of 183 mAhg−1. • The TBA-based battery has retained of 97% columbic efficiency even after 2000 cycles. [ABSTRACT FROM AUTHOR]

The article provides information about the environmental impact of man-made waste generated in industrial regions. Mineralogical and chemical properties of technogenic wastes of industrial regions, in particular, waste of coal mining, mining and industrial complex of phosphate and siliceous raw materials extraction in the Karatau phosphorite basin of the Republic of Kazakhstan are presented. The data on the chemical and mineralogical composition of ash and slag waste generated by the combustion of coal from the Karaganda and Ekibastuz basins are presented. The results of differential thermal and X-ray analyses of carbonate - siliceous dolomitized phosphate raw materials of the Aksai Deposit and its chemical composition are shown. The results of analyses of brown and hard coal ash from the Ekibastuz and Karaganda basins are presented. In addition, the reflectivity of ash formed after burning coal from the Bogatyr section of the Ekibastuz basin, as well as its physical and chemical properties and characteristics for macro and microelements, is given. [ABSTRACT FROM AUTHOR]

Design of new efficient membranes from sustainable sources such as coal fly ash (CFA) has been receiving rapidly growing attention. In the present work, alumina-based tubular asymmetric membranes were incorporated with different amounts of CFA using the centrifugal casting technique. The amount of CFA added to the matrix of the alumina tubes was varied from 10 to 40 wt% on a dry weight basis. The development of the ceramic membranes containing CFA comprised the following steps: raw materials dispersion, membrane preparation by centrifugal casting using high-speed mold rotation, drying of the green body followed by sintering at 1200 °C. The techniques used for membrane characterization included measuring mechanical strength, apparent porosity, morphology by scanning electron microscopy, linear shrinkage, hydraulic performance, and cornstarch retention. High CFA fraction in the alumina-based membranes resulted in higher porosity and higher water permeability, accompanied by a decrease in mechanical strength and linear shrinkage. The observed permeate flux was between 116 and 370 L m−2 h−1 bar−1, and the observed retention was above 99% for all the membranes tested. The addition of CFA for the preparation of asymmetric tubular membranes based on alumina allows utilization of industrial waste, reduces the cost and is interesting from both an economic and environmental points of view. These membranes have the potential for applications such as wastewater treatment and as a support for selective layer coatings. [ABSTRACT FROM AUTHOR]

The use of different types of zeolites (X, Na-P1, and 4A) synthesized by different methods and scales were tested in this work to adsorb nutrients present in synthetic solutions and industrial effluents for later application as fertilizer. Modifications with calcium chloride were performed on the zeolite with the best performance to increase its adsorption capacity. The best performing zeolite was type X (ZXH) produced on a pilot scale by the hydrothermal process. Its adsorption capacity without modification was 149 mg P-PO4/g zeolite and 349 mg K/g zeolite. With the change, there was a fourfold increase in these results, which were up to threefold higher than reported in the literature. The kinetic model that best characterized the adsorption process was the intraparticle diffusion model, and the equilibrium isotherm was that of Freundlich. The adsorption tests performed with industrial effluent showed high removal of the nutrients of interest (> 90% for PO43− and > 95% for K+). The desorption tests with zeolites nutrient-loaded from synthetic solutions showed 13 to 24% PO43− and 14 to 47% K+ release within 24 h, while for zeolite nutrient-loaded from effluent the release were 7 and 100% for PO43− and K+, respectively. The results we obtained in this work indicated the potential use of zeolites in the treatment of effluent and its application as a fertilizer. [ABSTRACT FROM AUTHOR]

Modern agriculture in Kazakhstan is carried out by an extensive method and accompanied by a noticeable decrease in soil fertility, in particular the biological and agrochemical properties as the main reason of insufficient fertilizer applications. The objectives of the research were to study the Agrobionov doses effect applied during soil preparation on microflora species composition, microbiological activity, availability of plant nutrients in soil, and barley grain yield. The preparation substances are produced from industrial wastes - coal ash, slag and carbon black. The experiments were carried out in the Northern Kazakhstan on the experimental field of Ualikhanov Kokshetau State University. The soil is represented by ordinary chernozem, carbonate, medium-power, lowhumus, heavy-loam. The cellulose-decomposing activity of soil bacteria was determined by the application of flax cloth. Microflora was studied on solid nutrient media, the productivity of barley grain by the continuous method. It has been established that preparation substances promote an increase in the total number of microorganisms, including nitrogen consuming microorganisms, oligonitrophils, phosphorus mobilizing, cellulose-decomposing, fungi, nitrogen nutrition improvement of soil, the increase of grain yield. The preparation substances improve biological properties, nutritional regime of soil, raises barley productivity, and also has ecological significance in terms of production waste utilization. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA) as an industrial solid waste has an extremely adverse influence on the environment. The high value utilization of CFA was a hot research topic with sustainable development for years. In this work, we found that CFA exhibits underoil superhydrophobicity and underwater superoleophobicity due to the special microstructures and chemical composition. And for the first time, CFA was used as a filter material for the separation of various oil/water mixtures and emulsions under the driven of gravity without any further chemical modification. Both light oil/water and heavy oil/water immiscible mixtures can be completely separated through CFA with almost 99.9% efficiency. More importantly, due to the "size-sieving" effect, CFA was capable of purifying various emulsions with high separation efficiency. After being pre-wetted with water, CFA displayed excellent separation capacity more than 92% and good flux as fast as 1050 L m−2 h−1 for water-in-oil emulsions. After being pre-wetted with oil, CFA exhibited a higher separation efficiency of 99.5% and a flux of over 935 L m−2 h−1 for water-in-oil emulsions. Therefore, this work provided an innovative, green, and low-cost approach for various oil/water mixtures and emulsions separation, which can also be widely used in wastewater treatment. Image, graphical abstract • CFA shows underwater superoleophobicity and underoil superhydrophobicity. • CFA was used for various emulsions separation without extra chemical treatment. • High efficiency of oil-in-water and water-in-oil emulsions separation was achieved. • The research presented an innovative approach for oil/water emulsion separation. [ABSTRACT FROM AUTHOR]

Featured Application: In this paper, the idea of the sustainability of durable solutions is very much present. The effect of four pozzolanic materials employed in four percentages in mortars made with two different reactive aggregates is assessed regarding alkali-silica reaction (ASR). The findings encountered here will help to optimize the cement-based materials mix design. The increased use of industrial wastes and by-products to produce concretes and blended cements is a lever to achieve carbon neutrality. Furthermore, they could improve their durability. Some pozzolanic additions can minimize the alkali-silica reaction (ASR), which is a well-known deleterious process that occurs between some reactive aggregates and the alkaline pore solution found in mortars and concretes. This work quantifies the efficiency of four pozzolanic materials (natural pozzolan, P, siliceous coal fly ash, V, silica fume, D, and blast-furnace slag, S) assessed by means of compressive strength testing, open porosity, ASR-expansion measurements, and SEM microscopy. Accelerated expansion tests were performed in mortar bars with a cement/sand ratio of 1/2.25 and a water/cement ratio of 0.47, two reactive aggregates and a non-reactive one. The major contributions of this paper are: (i) The more aggregate reactivity is, the higher ASR mitigation level was found when additions were added and (ii) The best additions for ASR inhibition are silica fume and fly ash. [ABSTRACT FROM AUTHOR]

The use of industrial wastes such as coal fly ash (CFA) and carbide lime (CL) can enhance the long-term performance of recycled asphalt pavements under freeze–thaw conditions as well as reduce consumption of natural resources. Further improvement of the mechanical properties of such blends can be achieved by adding small quantities of sodium chloride (NaCl). Blends of recycled asphalt, CFA, CL and sodium chloride were therefore assessed in terms of their durability to freeze–thaw exposure. Additional splitting tensile tests were performed to evaluate strength improvements after adding sodium chloride. Specimens were moulded with three different dry unit weights and two different lime percentages, and cured for 7 d. The accumulated loss of mass was evaluated as a function of the porosity/lime index, which broadens the applicability of this index by demonstrating it, and influences not only strength but also long-term performance. The improvement in engineering properties provided by sodium chloride was found to be related to the formation of mineral phase thomsonite and to sodium chloride acting as a catalyser. [ABSTRACT FROM AUTHOR]

A kind of mesoporous aluminosilicate oxides (MAOs) were fabricated from industrial waste, coal fly ash. After loaded with zinc on MAO, the product MAO‐Zn was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy (SEM). MAO‐Zn was incorporated with intumescent flame retardant (IFR) together and used in polypropylene (PP). Basic characterization including limiting oxygen index (LOI), vertical burning test (UL‐94), and cone calorimeter test (CCT) were finished. The result showed the LOI value of PP was only 17.7 and cannot pass UL‐94 grade; however, 25 wt% IFR in PP help the composite obtained LOI value of 27.6 and passed UL‐94V‐1 grade. Surprisingly, with only 2 wt% MAO‐Zn substitution of IFR, the LOI of PP/IFR composite sharply went up to 37.2 and passed V‐0 grade. CCT results documented that heat, smoke, and fatal gas release were obviously suppressed by IFR/MAO‐Zn combination. By SEM observation and quantitative analysis of TGA results, the contribution of MAO‐Zn was summarized as adsorption of heat/smoke and promotion on charring. It was worth mentioning that the low dose of MAO‐Zn (≤ 3 wt%) did not bring further deterioration on mechanical properties. J. VINYL ADDIT. TECHNOL., 26:135–143, 2020. © 2019 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Generally, conventional concrete does not conduct electricity but conducts when some conductive components are added to the conventional concrete. This concrete is called Electrically Conductive Concrete (ECC). The paper studies the suitability of industrial waste materials for making ECC. Different industrial wastes such as lathe turns of aluminum and steel, powder of brass and cast iron, copper slag and lignite bottom ash were used as conductive materials. It was observed that industrial wastes such as bottom ash and copper slag were suitable materials for making concrete by replacing fine aggregate. From the number of trials, the optimum quantity of industrial waste to replace the conventional fine aggregate river sand was found. Then two different ECC mixes, Mix with Bottom Ash (MBA) and Mix with Copper Slag (MCS), were prepared based on volume basis. The strength, electrical resistivity and thermal properties of both the ECC specimens were studied. [ABSTRACT FROM AUTHOR]

Due to increase in the growth of industrial sectors the power requirement of the country is rapidly increasing. India depends on Thermal Power as its main source, thus there is increase in power requirement every year. Present scenario of our country shows 75 % of country's total installed power generation is thermal of which coal-based generation is 90%. The coal reserves of the country are predominately of lower grades (average of 35% ash content), non-cooking and as a result more than 110 million MT coal ash is being generated every year. Ash generation may likely reach to 170 million MT by 2012. Use of coal brings huge amount of ash every year. Research related to new and innovative use of waste materials is being undertaken worldwide. Properties of materials include strength, hardness, density, resistance to corrosion, etc. Materials in industrial wastage has properties like unit weight, specific gravity, shrinkage, absorption, resistance to freezing, etc. The industrial waste material is a bye-product of construction industries and other industries and their wastes are fly ash, pond ash, marble dust, store dust, slag and many more. In this research study modifications in normal concrete materials such as cement aggregate and sand were carried out. Properties of concrete were replaced by fly ash and pond ash. The construction waste material which gives better performance in special concrete was identified. Fly ash and pond ash materials were selected which simultaneously replaces the cement and sand of the special concrete and better results were obtained related to the properties of concrete. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA), a byproduct of coal combustion, is a hazardous industrial solid waste. Its excessive global production, coupled with improper disposal practices, insufficient utilization and limited awareness of its inherent hazards, poses a significant threat to both ecological environment and human health. Based on the physicochemical properties of CFA and its leachates, we elucidate the forms of CFA and potential pathways for its entry into the human body, as well as the leaching behavior, maximum tolerance and biological half-life of toxic elements present in CFA. Furthermore, we provide an overview of current strategies and methods for mitigating the leaching of these harmful elements from CFA. Moreover, we systemically summarize toxic effect of CFA on organisms across various tiers of complexity, analyze epidemiological findings concerning the human health implications resulting from CFA exposure, and delve into the biotoxicological mechanisms of CFA and its leachates at cellular and molecular levels. This review aims to enhance understanding of the potential toxicity of CFA, thereby promoting increased public awareness regarding the disposal and management of this industrial waste. • The properties of CFA determine its pathway into organisms and toxicity. • High CFA levels have detrimental to soil microbial activity and plant growth. • CFA exposure causes more toxic effects on lab animals than wild animals. • CFA exposure linked to neurological issues in children and respiratory/cardiovascular problems in adults. • Endocytosis and pinocytosis are the primary means by which cells ingest CFA particles. [ABSTRACT FROM AUTHOR]

• Solid industrial wastes were the selected precursors for alkali activated material. • Physico-chemical properties and natural radioactivity of materials were evaluated. • Dosimetric indexes of the precursors, paste and mortars were determined. • It was found that geopolymers (in paste and mortar form) comply to Euratom Directive. Alkali-activated materials were prepared from four typical precursors (coal fly ash, granulated blast furnace slag, metakaolin, and brick waste powder) characterized for granulometry, elemental composition, and microstructure. High-resolution gamma-ray spectrometry was used to determine the activity concentration of Naturally Occurring Radioactive Materials (NORM) in all the materials to assess their radiological impact. All the investigated materials have been found to comply with the European dosimetric index (I) according to Directive 2013/59/Euratom. The results suggest the need for an accurate check of radioactivity throughout the mixing phases to prevent I exceedances. The productive chains were also evaluated by principal component analysis. [ABSTRACT FROM AUTHOR]

Coal ash (CA) is an industrial waste product that has been shown to contain several neurotoxic constituents such as cadmium, selenium, mercury, lead, and arsenic. Contaminant-laced leachates enter the environment via seepage, runoff, permitted discharge, or accidental spills from CA storage ponds or landfills which may pose a risk to wildlife residing in receiving waterways. In this study, we assessed 1) the presence and concentration of thirteen trace elements (Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, Fe, B) in surface water and sediment grab samples using ICP-OES, 2) the temporal variability of trace elements using Pb-210 dated sediment core samples, 3) differences in species diversity using environmental DNA (eDNA) analyses, and 4) the presence and concentration of trace metals in banded killifish (Fundulus diaphanus) epaxial muscle tissue collected from waterways surrounding the Possum Point Power Station (Stafford, VA). Results showed the highest concentrations of As, Cd, Cr, Cu, Fe, Mg, Se, Zn, and B in Quantico Creek (QC) adjacent to the coal ash ponds and elevated average cadmium and zinc concentrations compared to both upstream and downstream locations along the Potomac River. Sediment core profiles and Pb-210 analyses showed historical enrichment of several trace elements in QC beginning after the commissioning of the power plant in 1948. When compared to upstream and downstream sites, species diversity was drastically reduced in Quantico Creek based on eDNA identification. Muscle tissues of banded killifish collected in Quantico Creek displayed increased Al, Cd, and Zn concentrations compared to upstream and downstream sites. Collectively, our results demonstrate the potential impacts of coal ash landfills on aquatic ecosystems and suggest that further research is needed to fully inform risk assessment and remediation efforts. [Display omitted] • Elevated sediment As, Cd, Cr, Cu, Fe, Mg, Se, Zn, and B found adjacent to landfill. • Pb210 shows enrichment beginning after commissioning of power plant in 1948. • Fish tissues near coal ash landfill contained elevated Al, Cd, Zn concentrations. • Species richness declined near coal ash landfill based on eDNA assessment. [ABSTRACT FROM AUTHOR]