Search Results (104)

Artificial aggregates (AAs) are man-made construction materials, and their properties greatly depend on their manufacturing process (e.g., granulation and hardening) and the raw materials used. The conducted research aimed to determine the most advantageous composition of artificial aggregates prepared based on three wastes simultaneously: municipal waste incineration ash (MWIA), sediment from the bottom of a water reservoir (SBWR), recycled cement mortar (RCM)- which was the main waste. A production process of such aggregates was also developed, with the setting of the hardening temperature (20 °C, 200 °C, 400 °C). The X-ray diffractometry (XRD), differential thermal analysis (DTA), and thermogravimetry analysis (TGA) were used to characterize the waste. Then, the properties of cementitious composites prepared with artificial aggregate with the best strength parameters of 0–100% of the natural aggregate were determined. Carbon footprint calculations were performed for the production of artificial aggregate, depending on its composition and for cementitious composites. Full article

The present research aimed to design innovative wheat cultivation systems that are less resource-intensive, promote biodiversity, and show greater resilience to both biotic and abiotic stress. It was focused on the cultivation and characterization of two evolutionary populations (EPs) of common wheat, namely EP_Floriddia and EP_Li Rosi, grown in Italy, over two growing seasons. The EPs were cultivated in organic management under legume or wheat precessions. Physico-chemical analyses included thousand kernel weight (TKW), test weight (TW), and ash content. Location and genotype mostly influenced TKW; TW, instead, was affected only by year. Wholemeal flour from each sample was assessed for protein content (PC), total starch (TS), total antioxidant capacity (TAC), and total dietary fiber (TDF). Protein content was higher on leguminous precessions than on wheat; the opposite behavior was observed for TS. The growing season predominantly impacted on TAC and TDF values. Technological and rheological parameters such as alveograph W and P/L value, SDS sedimentation test, farinograph quality, gluten index, and falling number revealed EP_Li Rosi as the best for baking aptitude, although both EPs were characterized by weak gluten. These findings support the use of EPs under legume precession as an agroecological approach to pursue agrifood biodiversity, quality, and sustainability. Full article

This study investigates the concentrations and geochemical behaviour of strategic elements—including Li, Co, Ni, Cu, Ga, Ge, rare earth elements (REEs), and yttrium (Y)—in bottom ash samples from the Afşin–Elbistan thermal power plant, Türkiye. Thirty bottom ash samples were analysed, revealing average ∑LREE and ∑HREE concentrations of 86.3 µg/g and 3.3 µg/g, respectively, resulting in an L/H ratio of 24.9, indicating pronounced enrichment in light REEs. The total ∑REE + Y concentration (111 µg/g) is comparable to the background value for coal but approximately 1.5 times lower than those reported for average Chinese coals and the upper continental crust (UCC). REE contents significantly exceed those of sedimentary (5.36 µg/g), mafic (16.77 µg/g), and felsic (3.60 µg/g) rocks. Elevated Li (30.5 µg/g) and Ni (114.4 µg/g) concentrations point to a mafic magmatic source, whereas Cu (28.7 µg/g) likely originates from basic volcanic rocks such as those of the Dağlıca Complex and the Kemaliye Formation. Chondrite-normalised REE patterns show Dy depletion relative to mafic rocks and Ho depletion compared to sedimentary rocks. Positive δEu anomalies (>1) support a mafic or UCC provenance, while slightly positive δCe values indicate hydrothermal leaching influences. The co-precipitation of Ce with Ca–Mg hydroxides and clay minerals in coal-bearing lacustrine sediments is suggested. Ga enrichment is attributed to aluminium-rich clay minerals and organic matter. Overall, these geochemical signatures reflect combined inputs from hydrothermal leaching and volcanic weathering within a coal-bearing lacustrine environment. Full article

With intensifying watershed pollution pressures and growing ecological vulnerability, scientifically revealing and enhancing the water environmental carrying capacity is crucial for ensuring the long-term health of the basin and the sustainable socioeconomic development of the region. However, the dynamic regulatory mechanisms linking narrow-sense and broad-sense water environmental carrying capacity remain poorly understood, limiting the development of integrated management strategies. This study systematically investigated the changing trends of both the narrow-sense and broad-sense water environmental carrying capacity in the Harbin section of the Songhua River basin through model calculations, along with the regulatory mechanisms of its key influence indicators. The results of the study on the carrying capacity of the water environment in the narrow sense show that permanganate, total phosphorus, and ammonia nitrogen exhibited partial carrying capacity across water periods, while dissolved oxygen decreased during flat and dry periods, with only limited capacity remaining at the Ash River estuary and in the Hulan River. The biochemical oxygen demand in the Ash River was consistently overloaded, and total nitrogen showed insufficient capacity except during the abundant water period. Broad-sense analysis indicated that improving urbanization quality, water supply infrastructure, and drinking water safety could effectively reduce future overload risks, with projections suggesting a transition from critical to loadable levels by 2030, though latent threats persist. Correlation analysis between narrow- and broad-sense indicators informed targeted control strategies, including stricter regulation of nitrogen- and phosphorus-rich industrial discharges, restoration of aquatic vegetation, and periodic dredging of riverbed sediments. This work is the first to dynamically integrate pollutant and socio-economic indicators through a hybrid modelling framework, providing a scientific basis and actionable strategies for improving water quality and achieving sustainable management in the Songhua River Basin. Full article

Alkali metals in fuel seriously affect the normal operation of generator sets. Using agricultural waste (AW) from a corn field as raw material, the dynamic change of alkali metal K migration and transformation and the effect of competition between chlorine and sulfur on the behavior of AW were studied systematically. The results showed that transformation between different forms of K, especially water-soluble K, occurred. At low temperatures, K remained in the ash in the form of inorganic salt, and high temperature precipitated K and formed insoluble alkali metal compounds. Via FactSage thermodynamic equilibrium calculations, it was confirmed that KCl reacted with SiO₂ to form a K₂O·nSiO₂ molten mixture in combustion. K initially existed in the form of KCl (s) and K₂SO₄ (s), high temperature promoted its transformation and decomposition, and it was eventually released as KCl (g). During combustion, Cl was more volatile than K, while S reduced the release of K and Cl through sulfation reaction to reduce the sediment viscosity. Full article

Traditional landfill cover materials have low strength and poor dry–wet durability. Municipal solid waste incineration fly ash (MSWI FA) can be used to partially replace cement solidification dredging sediment (DS). This article investigates the possibility of using MSWI FA and ordinary Portland cement (OPC) composite cured DS as a covering material. The mechanical properties, permeability, and wet–dry durability of the cured system were investigated under the conditions of MSWI FA content ranging from 0% to 60% and OPC content ranging from 10% to 15%. The microscopic mechanism was analyzed by scanning electron microscopy and X-ray diffraction. The results showed that when the OPC and MSWI FA contents were 15% and 20%, respectively, the comprehensive performance of the cured specimens was best after 28 days of natural curing. The unconfined compressive strength reached 1993.9 kPa, and the permeability coefficient decreased to below 1 × 10⁻⁷ cm/s, fully meeting the requirements for landfill coverage. C-S-H gel is the main strength source of the solidified body, while Friedel salt and ettringite enhance the compactness of the matrix. An excessive moisture environment promotes the water absorption of soluble salts produced by MSWI FA hydration, leading to sample expansion and reduced strength. MSWI FA and OPC cured DS exhibit good compression performance in the intermediate cover system of landfills, and can maintain good engineering performance under periodic dry–wet cycles. This dual strategic synergy solves the hazardous disposal problem of MSWI FA and the resource utilization demand of DS, demonstrating enormous application potential. Full article

The use of mineral waste for the production of lightweight artificial aggregate is an important element of activities for sustainable development in construction and the implementation of the objectives of the circular economy. The article presents the physical, mechanical, and ecological properties of an innovative artificial aggregate produced from bottom sediments, concrete dust, and municipal solid waste incineration fly ash. The obtained research results confirm that the developed material achieves technological properties comparable to artificial aggregates available on the market, both commercial and those derived from recycling. However, the increased leachability of chlorides and sulphates remains a significant challenge, which may limit the scope of its applications. Despite this, the material shows the potential for use, among others, in the production of lightweight concrete. The analyses carried out have shown that the thermal hardening processes (200–400 °C) and autoclaving do not guarantee full immobilization of harmful substances contained in the raw materials for the production of this type of aggregate. Full article

The incorporation of mineral admixtures plays a crucial role in enhancing the performance and sustainability of geopolymer systems. This study evaluates the influence of fly ash (FA), silica fume (SF), and metakaolin (MK) as typical mineral admixtures on slag–Yellow River sediment geopolymer eco-cementitious materials. The impact of varying replacement ratios of these admixtures for slag on setting time, workability, reaction kinetics, and strength development were thoroughly investigated. To understand the underlying mechanisms, microstructural analysis was conducted using thermogravimetric–differential thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS), and mercury intrusion porosimetry (MIP). The results indicate that the incorporation of FA, SF, and metakaolin delayed the initial reaction, prolonged the induction period, and reduced the acceleration rate. These effects hindered early strength development. At 30% FA content, the matrix exhibited excellent flowability and sustained heat release. The 28-day splitting tensile strength increased by 42.40%, while compressive strength decreased by 2.85%. In contrast, 20% SF significantly improved compressive strength, increasing the 28-day compressive and splitting tensile strengths by 11.19% and 6.16%, respectively. At 15% metakaolin, the strength improvement was intermediate, with 28-day compressive and splitting tensile strengths increasing by 3.55% and 10.59%, respectively. However, dosages exceeding 20% for SF and metakaolin significantly reduced workability. The incorporation of FA, SF, and metakaolin did not interfere with the slag’s alkali-activation reaction. The newly formed N-A-S-H and C-S-H gels integrated with the original C-A-S-H gels, optimizing the pore structure and reducing pores larger than 1 µm, enhancing the matrix compactness and microstructural reinforcement. This study provides practical guidance for optimizing the use of sustainable mineral admixtures in geopolymer systems. Full article

Wheat plays a crucial role in global food security; however, in recent years, Fusarium Head Blight (FHB) has severely impacted both wheat yield and quality. Strong oxidative free radicals, with high oxidation potential and rapid reaction rates, offer an effective approach for pollutant degradation and microbial inactivation. In this study, the control effect of strong oxidizing radicals on FHB was evaluated by comparing the untreated control group (JM23), which was infected with FHB, to the experimental group (FG06), which was treated with strong oxidizing radicals following FHB infection. The results show that FG06 achieved a control effectiveness of 87.87%. The study also assessed grain characteristics and milling quality. Statistical analysis revealed that FG06 had a slightly lower flour extraction rate (71.24%) compared to the control wheat (JM23), but it exhibited competitive flour whiteness (81.30) and a gluten index of 85.50%. The dough stability at 10 min was 27.00 FE, while several gelatinization parameters were significantly lower than JM23. However, FG06 had higher protein content (10.94%), flour protein content (10.70%), ash content (0.58%), wet gluten content (28.70%), dry gluten content (9.40%), and sedimentation value (73.00 mL), all significantly higher than those of JM23. Additionally, FG06 had a gelatinization temperature of 68.61 °C, similar to JM23. Overall, Strong oxidizing radicals as an alternative to conventional pesticides not only effectively controls FHB but also maintains or even enhances wheat milling and processing quality, promoting more sustainable agricultural practices. Full article

The research hypothesis assumes that Fusarium culmorum infection affects the baking value of wheat. The aim of the research was to determine the effect of the cultivar on the rheological properties of wheat dough in response to Fusarium culmorum infection of wheat. A two-factor experiment conducted during the 2018–2020 growing seasons in Osiny, Poland, was set up using the completely randomized block design with three replications. The first factor was winter wheat cultivars (six cultivars), while the second factor was inoculation (two levels—Fusarium culmorum and distilled water—control). The immunoenzymatic ELISA method was used to determine the content of deoxynivalenol (DON) in grain. The DON content in the grain varied between cultivars. Fusarium culmorum inoculation resulted in an increase in protein, ash content, and flour water absorption, changes in dough rheological properties, and a decrease in the sedimentation index. Inoculation also caused negative changes in starch properties. The observed interaction between Fusarium culmorum inoculation and cultivars in shaping the qualitative parameters and rheological properties of the dough indicates that there are wheat cultivars less susceptible to Fusarium infection, which do not show any significant changes as a result of infection. Full article

This research presents the impact of diesel blends with tire pyrolysis oil (TPO) as an additive for minimizing the wear and tear of engine components. This study investigates the blends of normative diesel oil with TPO content ranging from 5% m/m to 20% m/m. Reference measurements are made for pure diesel oil (D100) and pure TPO. This investigation included an evaluation of the corrosion effect and the effect of the fuels tested on abrasive wear. For each fuel, the sulfur content, water content, lubricity (which is defined as the corrected average diameter of the wear trace during the high-frequency reciprocating rig (HFRR) test), and impurity content are determined. Impurities are assessed using indicators such as ash residue, coking residue from 10% distillation residue, determination of wear metals and contaminants, insoluble impurity content, and total sediment by hot filtration. All parameters are determined using recognized methods described in international standards. Approximation models are built for all the analyzed parameters, which can be used in future studies. At the same time, the individual values of the analyzed factors are compared with the threshold values specified in selected standards and regulations. Consequently, it is possible to assess the usefulness of individual fuels in terms of meeting the requirements for minimum wear of engine components. The results show the suitability of pyrolysis oil and the potential for its use as an additive to fossil fuels in terms of meeting most factors. Some of the fuels tested did not meet the standards for acceptable sulfur content. However, in terms of sulfur content, all of the analyzed fuels can be used to power watercraft and land-based power and thermal power plants equipped with flue gas desulphurization systems. A second indicator for not meeting the standards is the ash residue value, which indicates the high content of non-combustible, mainly metallic, substances in the pyrolysis oil used for the tests. Post-recycled oils must, therefore, undergo appropriate purification before being used as an additive to diesel fuels for internal combustion engines. Once the post-recycling oil has been subjected to desulfurization and advanced filtration, it can be used as a fuel additive for land vehicles, which fits in with closed-loop economies and sustainable development strategies. Full article

Two sets of sediment samples were collected from the Sarigiol basin, Greece, aiming to evaluate the environmental consequences of the industrial activity in the area by assessing their magnetic properties with the magnetic susceptibility method. Chemical composition and morphological characteristics of magnetic particles were defined by EDX analysis and scanning electron microscopy, respectively. Based on the results, most of the study area shows positive values of the difference between X_LF values of the samples, indicating the influence of fly ash dispersion from Agios Dimitrios and Kardia power plants and the conveyor belt, down to a depth of 50 cm. Negative values in the NE, W and S parts of the study area are attributed to ophiolite complexes. Anthropogenic and lithogenic magnetic particles were identified at a 50 cm depth, in the form of spheres and octahedrons, respectively. Fe is the dominant element while Al, Si, Mg and Ca were found in minor amounts. Cr increases with depth, pointing mainly to a lithogenic source, while Ti decreases, suggesting a relationship with the dispersed fly ash particles. Mn and Zn were found in limited magnetic spheres. These findings highlight the need for effective environmental management strategies and are valuable keys for soil pollution control. Full article

Agro-industrial activities generate significant amounts of organic waste and a variety of effluents thus posing environmental challenges. Viticulture in Argentina, which covered 204,847 ha in 2023, faces water scarcity as a limiting factor conditioning its production. This industry produces large volumes of grape marc, sediments, and stalks, which can be valorised into products like alcohol, tartaric acid, and compost. However, these valorisation processes generate effluents with high organic load and salinity, further stressing water resources. This study explores the potential of utilising these effluents to cultivate plant biomass in arid regions (sorghum or perennial pasture), which could serve as bioenergy, animal feed, or composting co-substrates, contributing to circular bioeconomy principles. The combined use of effluent as a water resource and the sowing of sorghum and pasture increased soil organic matter content and led to a slight reduction in pH (depth: 0.30–0.60 m) compared to the control treatment. The sorghum plots showed better establishment and higher dry biomass yield (32.6 Tn/ha) compared to the pasture plots (6.5 Tn/ha). Sorghum demonstrated better tolerance to saline soils and high salinity effluents, aligning with previous studies. Although pasture had a lower biomass yield, it was more efficient in nutrient uptake, concentrating more NPK, ash, and soluble salts. Sorghum’s higher yield compensated for its lower nutrient concentration. For biomass production, sorghum is preferable, but if nutrient capture from effluents is prioritised, summer polyphytic pastures are more suitable. These results suggest that the final selection between plant biomass alternatives highly depends on whether the goal is biomass generation or nutrient capture. Full article

The sedimentation process of coal slurry water is influenced by numerous factors and has complex mechanisms. Its nonlinear and large hysteresis characteristics pose great challenges to process optimization control, making it a current research hotspot. This paper takes the typical slime water treatment process of a coal preparation plant as the object, and, on the basis of selecting raw coal quantity, flocculation dosage, coagulation dosage, overflow turbidity, raw coal ash content, underflow concentration, and slime quantity as the key variables, establishes a quality control method for process detection data consisting of data acquisition → data anomaly detection → data filling and noise reduction; subsequently, different machine-learning algorithms are used to predict the performance of coal-slurry-settling agents. It was found that Long Short-Term Memory shows the highest prediction accuracy for coagulants, with corresponding root mean square errors of 2.72% and 6.23%. Finally, using iFix software (version 5.5), an intelligent control system for the settling process of coal slurry water was constructed, which reduced the usage of coagulants by 31.56% and 37.21%. Full article

Investigation of the critical metal elements in coal and coal-bearing strata has become one of the hottest research topics in coal geology and coal industry. Coal-hosted Ga-Al-Li-REE deposits have been discovered in the Jungar and Daqingshan Coalfields of Inner Mongolia, China. Gallium, Al, and Li in the Jungar coals have been successfully extracted and utilized. This paper reviews the discovery history of coal-hosted Ga-Al-Li-REE deposits, including contents, modes of occurrence, and enrichment origin of critical metals in each coal mine, including Heidaigou, Harewusu, and Guanbanwusu Mines in the Jungar Coalfield and the Adaohai Coal Mine in the Daqingshan Coalfield, as well as the recently reported Lao Sangou Mine. Gallium and Al in the coals investigated mainly occur in kaolinite, boehmite, diaspore, and gorceixite; REEs are mainly hosted by gorceixite and kaolinite; and Li is mainly hosted by cholorite. Gallium, Al, and REEs are mainly derived from the sediment-source region, i.e., weathered bauxite in the Benxi Formation. In addition, REE enrichment is also attributed to the intra-seam parting leaching by groundwater. Lithium enrichment in the coals is of hydrothermal fluid input. The content of Al₂O₃ and Ga in coal combustions (e.g., fly ash) is higher than 50% and ~100 µg/g, respectively; concentrations of Li in these coals also reach the cut-off grade for industrial recovery (for example, Li concentration in the Haerwusu coals is ~116 µg/g). Investigations of the content, distribution, and mineralization of critical elements in coal not only provide important references for the potential discovery of similar deposits but also offer significant coal geochemical and coal mineralogical evidence for revealing the geological genesis of coal seams, coal seam correlation, the formation and post-depositional modification of coal basins, regional geological evolution, and geological events. Meanwhile, such investigation also has an important practical significance for the economic circular development of the coal industry, environmental protection during coal utilization, and the security of critical metal resources. Full article