Search Results (3,253)

The discharge of metal-complex dyes from textile industries poses significant environmental challenges due to their chemical stability and resistance to conventional biological treatment. This study examined the degradation of Acid Black 194 (AB–194), a 1:2 chromium-complex azo dye, using Co²⁺-activated peroxymonosulfate (PMS). A central composite design based on response surface methodology was used to evaluate the effects of Co²⁺ (5.93–20.07 µM), PMS (1.67–7.33 mM), and dye (13.79–56.21 mg L⁻¹) concentrations on decolorization and mineralization. The polynomial models demonstrated strong predictive accuracy (R² > 0.9896), identifying Co²⁺ and dye concentrations as the most influential factors. Under optimal conditions (18.0 µM Co²⁺, 6.5 mM PMS, 20.0 mg L⁻¹ dye), 99.19% decolorization was achieved at 30 min and 41.43% TOC removal at 240 min. Degradation kinetics were described by a mechanistic model incorporating 15 elementary reactions that comprise the Co²⁺/Co³⁺ redox cycle, radical generation, and dye oxidation, yielding a global R² of 0.9617. Estimated rate constants for dye oxidation (k₁₄ = 3.52 × 10⁹ M^–1 s^–1 for and k₁₅ = 2.00 × 10¹⁰ M^–1 s^–1 ) were consistent with values reported for aromatic compounds in sulfate radical systems. Radical contribution analysis confirmed sulfate radicals as the principal oxidizing species, accounting for 96.75% of the overall process. Full article

The construction of green mines is a core strategy for promoting ecological civilization in China’s mining sector, yet its long-term ecological effects require quantitative assessment. Using a cement-grade limestone mine operated by Linyi Zhonglian Cement Co., Ltd. in Shandong Province as an illustrative case, we employed Landsat 8 OLI/TIRS imagery acquired in 2015, 2020, and 2025 to develop a five-indicator framework for assessing ecological environment quality. The selected indicators comprised greenness (NDVI), wetness, dryness (NDBSI), land surface temperature (LST), and dust concentration (MECDI). These five indicators were subsequently integrated via principal component analysis to generate the Mine Ecological Quality Index (Mine-EQI). Using this index, we applied the Theil–Sen median slope estimator alongside zonal statistics to examine ecological change trajectories across the full study area and three functional zones—the industrial square, haul roads, and active mining area—over the 2015–2025 period. The ecological outcomes attributable to the green mine policy were then quantified. The results show that (1) the mean Mine-EQI of the study area decreased from 0.3713 in 2015 to 0.3460 in 2025, exhibiting a slight overall decline. However, the rate of decline decreased from −6.1% during 2015–2020 to −0.7% during 2020–2025, yielding a Temporal Change Intensity index (TCI) of +88.5%, indicating that the ecological degradation trend has been effectively curbed. (2) Significant spatial heterogeneity was observed. The industrial square showed substantial improvement (Theil–Sen slope = +0.0726), while the haul roads (slope = −0.0705) and mining area (slope = −0.0408) continued to exhibit degradation trends. The improved areas (9.7% of the study area) were spatially coincident with green mine engineering projects. (3) The dust indicator (MECDI) decreased by 24.7% during 2020–2025, and the vegetation index (NDVI) increased by 19.5% over the decade, representing the dominant contributors to ecological improvement. This study reveals that China’s green mine policy has yielded remarkable ecological improvements in relatively stable functional zones such as industrial squares. In contrast, ecological restoration within persistently disturbed areas, including haul roads and mining pits, demands long-term sustained investment and governance. By integrating remote sensing techniques with policy analysis, this research establishes a replicable framework for evaluating progress toward sustainable mining practices. The findings directly support the monitoring of SDG 12 (Responsible Consumption and Production) and SDG 15 (Life on Land), providing a quantitative pathway to balance mineral resource extraction with ecological protection—a core sustainability challenge for resource-dependent regions. Full article

Smolt production in freshwater is an essential component of the salmonid aquaculture production chain. But it generates sludge (feed waste and fish feces) that must be managed to meet environmental regulations. While sludge can be reused as a resource, there are limited empirical results about cost structures, market conditions, and energy implications in industrial aquaculture. This study analyzes sludge collection, processing, and utilization based on a single-case study of a Norwegian smolt producer (Sisomar AS). The analysis combines company-level production data, accounting information, and process descriptions. In 2023, the company produced approximately 9.2 million smolt (1184 tons of biomass), generating 140 tons of dried sludge. Sisomar’s value creation from production of bio-based fertilizer from sludge is relatively close to that of comparable mineral fertilizers, but a direct comparison here is difficult because of large variations in the prices of mineral fertilizers. The energy consumption is significantly lower for organic fertilizer from Sisomar compared to standard technology for mineral fertilizer production. Bio-based fertilizers are looked at as an important contribution to dealing with environmental challenges, and this study discusses the characteristics of how market structures have importance for this. Full article

This study assesses export concentration risk in four Central Asian economies (Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan) by examining trade specialization patterns in 31 mineral, chemical, textile, and metallurgical product groups over 2017–2024. Using a multi-index framework based on Revealed Symmetric Comparative Advantage (RSCA), Relative Trade Advantage (RTA), and the Lafay Index (LI), the paper distinguishes structurally embedded competitive advantages from export signals that are weak, import-dependent, or potentially transient. The revised analysis adds explicit data consistency checks, a clarified classification rule, and robustness tests based on sign concordance, majority-index rules, and RSCA-only thresholds. The results show that Central Asia’s risk profile is highly persistent but heterogeneous: Tajikistan is exposed to extreme single-commodity risk in aluminium and cotton-related segments; Kazakhstan remains vulnerable to mineral-fuel concentration and energy-price volatility; Uzbekistan has broader but still labour-intensive textile specialization; and Kyrgyzstan shows ambiguous competitiveness that may partly reflect re-export and transit-related trade. Fully competitive product groups are confined mainly to resource- and labour-intensive activities, while chemicals and technologically complex manufacturing remain non-competitive across the region. The findings support risk-differentiated policy responses, including commodity-price hedging, counter-cyclical stabilization tools, downstream processing, textile upgrading, and regional value-chain development. Full article

Hops (Humulus lupulus L.) is a plant species with a multitude of uses in medicine, food science and agriculture. Xanthohumol, the major prenylflavonoid in hop cone extract, possesses anti-cancer activity. Xanthohumol also exhibits strong antimicrobial activity against Gram-positive bacteria (e.g., S. aureus), but not against Gram-negative bacteria. Xanthohumol can reduce blood glucose levels and body fat in obese male rats (not females), and mature hop bitter acids (MHBAs) have been found to decrease visceral and abdominal human fat. Xanthohumol can increase bone mineral density, decrease osteoclast numbers, and protect osteoblasts from oxidative stress in osteoporotic mice. Further clinical research, xanthohumol and bitter acids could be sourced from hop cone extracts to formulate novel drugs that can successfully treat a variety of diseases and potentially replace current therapies that have negative effects. In the food industry, hop cone extracts are mainly used in the brewing industry, with 98% of the world’s hop cones being used in brewing beer. Hop cone extracts are also used as food/drink preservatives due to their antimicrobial abilities, as previously mentioned, although there is less of a need for hops in extending food/drink shelf-life. Finally, hop cone extracts have several uses in agriculture, mainly as pesticides. For example, hop extracts can kill varroa mites, a parasite that impairs honeybee health. This benefits honeybee farmers as increased bee survival means more honey production, increasing profits. Overall, this review paper brings together recent studies that highlight hop extracts as valuable bioactive compound mixtures with many useful applications. Full article

Chromium slag, a chromium-bearing solid waste characterized by substantial environmental hazards yet with appreciable resource potential, has become a focal topic in solid-waste pollution control and the circular economy. Centered on the overarching logic of “evidence chain–system boundary–scalable and verifiable acceptance,” this review systematically synthesizes recovery technologies, industrial-scale utilization pathways, and the key challenges associated with the detoxification and resource utilization of chromium slag. From the perspective of recovery technologies, we examine pyrometallurgical and hydrometallurgical routes, solidification/stabilization (S/S), and bioelectrochemical coupling approaches, elucidating their fundamental principles, applicability boundaries, and critical nodes where environmental burdens may be transferred across media. We emphasize that process design should concurrently consider detoxification efficiency, resource recovery performance, and whole-process pollution control. Regarding utilization pathways, this review highlights three major routes with strong scale-up relevance—metallurgical process co-treatment (CAP–sintering–blast furnace), bulk utilization in construction materials, and high-value utilization—and analyzes their industrial potential and engineering constraints. Particular attention is given to the lack of long-term leaching and durability evidence, which represents a central bottleneck limiting product-side credibility. Furthermore, we discuss cross-cutting challenges including the long-term stabilization of Cr(VI), the verifiability of “green utilization” concepts, cost and economic feasibility, and standardized acceptance criteria. We propose that future research should shift from single-process optimization toward multi-objective, system-level evaluation, and establish a full-chain evidence system covering “speciation/mineral phases–process mechanisms–environmental behavior–risk assessment–engineering scale-up–standardized acceptance.” This review aims to provide a systematic analytical framework and practical reference for improving comparability across resource-utilization technologies and supporting engineering decision-making for chromium slag management. Full article

Under grazing conditions, it is difficult for lactating Yili mares to meet their nutritional requirements and those of their suckling foals solely through the consumption of natural pasture. Furthermore, seasonal variations and rainfall significantly influence the quality and nutrient content of forage, which severely constrains the healthy breeding of Yili horses and the industrial development of mare milk resources. Therefore, this study aimed to investigate the effects of concentrate supplementation on lactation performance and milk concentrations of amino acids, fatty acids, and mineral elements in Yili horses under grazing conditions. Twenty-two healthy Yili mares in early lactation, with similar ages (3–4 years), foaling dates, and body weights (391.5 ± 13.74 kg), were randomly assigned to either a grazing group (G, n = 11) or a grazing + supplementation group (GS, n = 11). Mares in group G grazed naturally on pasture, while those in group GS received 1 kg of concentrate supplement twice daily (totaling 2 kg/day) in addition to grazing. The experimental period lasted for 100 days, including a 10-day adaptation period and a 90-day formal experimental period. The results showed that: (1) In terms of lactation performance, the GS group exhibited highly significant increases in milk yield and lactose yield (p < 0.01), as well as significant increases in milk protein and milk fat yields (p < 0.05), with an extended duration of the peak lactation period. (2) Regarding the amino acid profile, the concentrations of threonine (Thr), serine (Ser), glycine (Gly), and alanine (Ala) in the milk of the GS group were significantly higher than those in the G group (p < 0.05), whereas the proline (Pro) content was significantly lower (p < 0.01); supplementation improved the uptake of certain functional amino acids by the mammary gland. (3) Concerning the fatty acid profile, the concentrations of polyunsaturated fatty acids (PUFA) and alpha-linolenic acid in the milk of the G group were significantly or highly significantly higher than those in the GS group (p < 0.05 or p < 0.01). (4) For mineral elements, concentrate supplementation highly significantly decreased the potassium (K) content and the K/Na ratio in horse milk (p < 0.01), highly significantly increased the levels of iron (Fe) and cobalt (Co) (p < 0.01), and significantly enhanced the chromium (Cr) content (p < 0.05). In conclusion, concentrate supplementation during grazing improved lactation performance in Yili mares, primarily by increasing milk yield and extending the peak lactation period. However, grazing alone was more favorable for maintaining higher PUFA and α-linolenic acid proportions in milk. Therefore, concentrate supplementation should be regarded as a nutritional strategy that increases milk output and modifies amino acid and mineral element composition, but may involve a trade-off with some beneficial fatty acids. Full article

The asbestos mine “Stragari” (Kragujevac municipality, central Serbia) operated for approximately four decades, exploiting chrysotile asbestos and generating several million tons of tailings composed primarily of finely crushed serpentinite rock. These tailings are rich in magnesium (≈25 wt.%); yet, efficient magnesium recovery is hindered by the high acid consumption associated with serpentinite mineral dissolution. The objective of this study was to optimize the extraction of magnesium as magnesium chloride hexahydrate (MgCl₂×6H₂O) from asbestos mine tailings using hydrochloric acid as the leaching agent. The effects of key process parameters (including thermal activation—roasting, hydrochloric acid concentration, leaching temperature, and leaching duration) were systematically investigated. Experiments in this study were conducted using concentrations of HCl 0.5, 1, 1.5 and 2 M, temperatures of 60, 70 and 80 °C and durations of 60 and 180 min, with constant stirring speed (350 rpm) and 20% initial pulp density. The resulting pregnant leach solution was purified by controlled neutralization with Mg(OH)₂ followed by evaporation to obtain MgCl₂×6H₂O. A preliminary techno-economic assessment indicates that the proposed process is economically feasible and provides a foundation for future scale-up studies. The results demonstrate that balancing acid consumption with magnesium recovery, rather than pursuing maximum extraction efficiency, can enable profitable industrial-scale production of a value-added magnesium compound while contributing to asbestos tailings remediation. Full article

The stability of upstream tailings remains a critical geotechnical challenge due to the inherently weak mechanical properties of fine-grained mine tailings. This study investigated a tailing improvement method using (i) emulsified polymer and (ii) combinations of recycled gypsum and cement kiln dust (CKD). A comprehensive experimental program—including unconfined compressive strength (UCS) analysis, direct shear tests (DSTs), and oedometer consolidation tests—was conducted to assess the performance of various treatment mixtures. The results showed that blends of CKD and gypsum, particularly at a 1:2 ratio and a 10% dosage, significantly improved shear strength, reduced compressibility, and lowered hydraulic conductivity by over an order of magnitude. The inclusion of plaster (commercial gypsum) further enhanced the UCS by more than 100% compared to recycled gypsum and increased the cohesion (c’) values from 0 to 32.8–47.2 kPa. The compression index (c_c) decreased from 0.15 to 0.05, and the maximum volumetric strain (ε_v) at an applied effective stress of 800 kPa decreased from 17% to 5%. Emulsified polymer treatments also enhanced the mechanical and hydraulic properties of the clayey tailings; however, the overall improvements were lower than those achieved with CKD–gypsum blends, suggesting that further optimization of the polymer concentration or its combination with mineral additives may yield better results. These findings offer a foundation for further research into the use of polymers in geoenvironmental applications, particularly for erosion control, contaminant encapsulation, and hydraulic barrier development. Overall, this study highlights the potential of using industrial by-products, such as CKD and gypsum, as sustainable, cost-effective materials to improve tailing performance, while identifying promising directions for polymer-based solutions in geotechnical engineering. Full article

Clay minerals in coal play a key role in controlling mineralogical composition, geochemical signatures, and the industrial behavior of coal and its combustion residues. This study investigates the occurrence, provenance, and potential applications of clay minerals in Carboniferous ash-rich coals from the Bogatyr, Lenin, and Saradyr coal mines in northeastern Kazakhstan. A total of 60 coal samples were analyzed using XRD, SEM–EDS/BSE, XRF, and ICP-OES following acid leaching. Based on ash yield, 52 samples were classified as coal (<50% ash), while 8 samples were classified as carbonaceous shale or mudstone (>50% ash). Mineralogical assemblages show clear variability among the studied mines. Saradyr samples are strongly quartz-dominated with lower clay proportions, Bogatyr samples exhibit highly heterogeneous quartz–clay–mica assemblages, whereas Lenin samples are relatively more clay-rich and dominated by kaolinite and illite-group minerals. Across all samples, kaolinite is the dominant clay mineral (16.6–46 wt.%), occurring mainly as authigenic pore- and cell-filling aggregates. Minor phases include illite–muscovite (7.1–29.9 wt.%), illite–smectite (up to 7.6 wt.% in Bogatyr), and smectite–montmorillonite (0.4–0.7 wt.%). Clay minerals occur as discrete particles, coatings, and pore fillings, contributing to ash formation; however, their correlation with ash yield is weak (R = 0.03–0.05), reflecting heterogeneous mineral inputs and diagenetic overprinting. All geochemical data are reported on a high-temperature coal ash (HTA) basis (815 °C). Geochemical indices (CIA, CIW, CIX) and Al₂O₃/TiO₂ ratios (1.8–17.4) indicate variable provenance and moderate to high weathering intensity, reflecting mixed mafic to intermediate source rocks. A total of 23 trace elements were identified. Au occurs at trace levels (up to 0.02 ppm), while selected rare earth elements (REE: Ce, Dy, Eu, La, Nd, Sm, Y, Yb) average 0.2–0.3 ppm, indicating negligible economic recovery potential. REEs show a strong positive correlation with clay minerals (r = 0.93), indicating adsorption and minor structural incorporation. In contrast, Au correlates with As, V, Zn, Cu, Ni, and Nb, suggesting sulfide association. HTA is enriched in SiO₂–Al₂O₃ phases dominated by kaolinite and quartz, indicating strong potential for cement, geopolymer, ceramic, and zeolite applications. Full article

Petroleum is a valuable mineral resource from which base fuels and innumerable materials are produced. Its optimized utilization requires a deeper understanding of its chemistry, that can be obtained by improved characterization and molecular modeling approaches. Since the introduction of the molecular modeling strategy in 1989 up to now the number of publications has increased exponentially, but a comprehensive review, that tracks the evolution in the development of molecular modeling, based on improved oil characterization methods, and process simulation in petroleum research and industry, has not appeared yet. For that reason 459 published studies, dedicated to the progress in petroleum characterization methods, which support the advance in molecular reconstitution, and to process simulation in petroleum refining, found in Scopus, American Chemical Society (ACS), Wiley, Springer, Taylor and Francis, MDPI, Google Scholar and others for the period 1989–2025 and the beginning of 2026, were reviewed. From virtual oil molecules used in the pioneering studies of molecular modeling the advance in the semi-quantitative characterization of petroleum enabled the molecular models of petroleum to become molecular-characterization-informed models. The advance in the optimization algorithms together with the progress of the hardware allowed 423-fold reduction in computation time, that enabled involvement of the molecular reconstruction models in refining process models and optimizing refining performance. The progress achieved in the molecular reconstitution of petroleum allows its application in crude oil selection in petroleum refining and for geochemistry studies. Full article

The global transition toward low-carbon energy and advanced technologies has intensified demands for rare earth elements (REEs), while available data remain fragmented across government and academic sources. To address this gap, this study compiles and standardizes a publicly accessible geochemical database of REE concentrations (among other variables) across Peru, motivated by the need for consolidated, evidence-based resource assessment. The dataset integrates over 30,000 records from national agencies and university repositories, classified by sample source (stream sediments, rocks and minerals, deep and surface soils, tailings, and industrial materials). This structure enhances comparability and interpretation across geological and environmental contexts. By providing a centralized, high-resolution dataset for an undercharacterized mineral province, this work offers a resource for exploration, policy development, and sustainable management amid growing global demand and strategic interest in critical minerals. Full article

This study examined alkali-activated granular aggregates produced from biomass fly ash, coal fly ash, and basalt dust. The work focused on multicomponent industrial waste mixtures activated with two sodium silicate-based systems and on the effect of carbonation curing on aggregate properties. Twelve designed mixtures and reference series were evaluated in terms of particle density, water absorption, and mechanical performance. The response to carbonation was also analysed to assess the potential for CO₂ uptake. Mechanical performance ranged from low to moderate and depended on mixture composition, activator type, and carbonation treatment. In most cases, the blended activator produced higher strength before carbonation than sodium silicate alone, whereas carbonation frequently reduced strength. Mixtures containing more basalt dust and less biomass fly ash generally showed the most favourable combination of properties. The results indicate that these industrial mineral wastes can be used to produce alkali-activated granular aggregates with adjustable properties, while carbonation curing may additionally contribute to phase changes and limited CO₂ binding. Full article

Phthalate acid esters (PAEs) are persistent organic pollutants (POPs) widely prevalent in industrial wastewater, posing significant threats to both ecological environments and human health. Although Advanced Oxidation Processes (AOPs) are recognized as efficient technologies for PAE degradation, conventional synergistic systems typically employ a simultaneous dosing mode. This approach often leads to the instantaneous quenching of excess radicals, low oxidant utilization, and imbalanced degradation kinetics. Despite its critical role in determining efficiency and costs, the dosing strategy remains an overlooked factor in current research. In this study, dimethyl phthalate (DMP) was selected as the target pollutant to evaluate a synergistic FeSO₄/H₂O₂/K₂S₂O₈ system. An innovative continuous dosing strategy was implemented to optimize radical utilization. A laboratory-scale continuous flow apparatus was developed to simulate industrial onsite conditions, enabling a systematic comparison of degradation kinetics, mineralization characteristics, and radical evolution between the two dosing modes. Results indicated that the degradation rate constant for the continuous dosing system reached 0.659 h⁻¹, representing a 21.1% increase over the simultaneous dosing system (0.544 h⁻¹). Electron Paramagnetic Resonance (EPR) analysis confirmed that the continuous dosing mode maintains a sustained and stable radical flux (^•OH and SO₄^•−) during the critical mid-stage of the degradation, effectively mitigating radical–radical quenching. When applied to real industrial wastewater (salinity: 2083 mg/L), the continuous dosing system achieved a Total Organic Carbon (TOC) removal efficiency of 86.0% at ambient temperature and initial raw water pH, outperforming the simultaneous dosing system (82.0%). GC-MS analysis further confirmed the thorough mineralization of complex organic compounds, especially those containing ester groups and aromatic rings. This research addresses a critical gap in dosing strategy studies, providing an efficient, cost-effective, and industrially viable solution for recalcitrant wastewater treatment while establishing a theoretical foundation for large-scale continuous dosing applications. Full article

Significant amounts of food waste come from fruit processing, causing economic and environmental impacts. The waste generated is a valuable source of compounds due to its concentration of nutrients, such as dietary fiber, vitamins, minerals, lipids with mono- and polyunsaturated fatty acids, and bioactive compounds. Despite the nutritional and functional qualities of the waste, it is still commonly discarded and underutilized, demonstrating the importance of studying it. The selected fruits described in this study are widely consumed by various populations around the world and are used at an industrial scale. The objective of this review is to discuss the use of seeds from grapes, passion fruit, melon, watermelon, papaya, guava, raspberry, and pomegranate and their benefits for human consumption. The seeds stand out for the possibility of oil extraction, creating a sustainable and healthy mode of production. Due to their nutritional composition rich in polyunsaturated fatty acids, they have been shown to be beneficial to health, promoting development, strengthening the immune system, and promoting the growth and maintenance of cell membranes, cardiovascular benefits, and antimicrobial and antioxidant activity, in addition to innovation in the cosmetics sector and applicability as biofuel. Therefore, the exploitation of this type of by-product shows promise in the search for alternative sources of vegetable oils and bioactive compounds with high added nutritional value and potential nutraceutical application, helping to increase the value of food waste and thus contributing to a better use of plant resources. Full article