Search Results (9,633)

Clay mineral diagenesis occurs in all buried siliciclastic sediments, albeit fine-grained and low-permeable or coarse-grained and highly permeable. Because of the limited permeability after compaction, this sheds doubt on the presumption that fluid flow is a causal factor in burial diagenesis besides temperature and effective pressure conditions. To assess the influence of fluid flow on their diagenesis, a number of sandstones have been studied focusing on clay minerals. In the studied sandstones, the authigenic clay minerals show a considerable variation in their chemical composition and mineralogy. In particular, authigenic illite and chlorite are common as authigenic cements in sandstones, often forming grain-rimming cements. Each of these two authigenic clay minerals varies distinctly in chemical composition, mineralogy and crystal habit at a small scale, compared to individual pores and laminae/beds. This indicates that local conditions determined not only which authigenic clay minerals formed, but also their chemical composition. Local conditions include the detrital mineral assemblage, specific textural features including clay grain coatings, and the ratio of the volume of susceptible components to pores. During burial diagenesis, a number of elements involved in clay mineral authigenesis, including Al, K, Mg and Fe, are locally fixed by clay mineral precipitation. In addition, diagenesis is driven by the amount and distribution of susceptible detrital components and the changes in physical conditions including temperature and effective pressure. The physical conditions allow chemical processes to commence and continue. The evidence presented is inconsistent with external fluid flow as a causal agent of burial diagenesis, supporting a largely closed, diagenetic system. Full article

To control the quality of mineral-medicinal waters and ensure their therapeutic benefits, spas often rely on periodic discrete sampling to analyze the physico-chemical properties of their pools. The AQUAPRED project aims to digitize this process by deploying IoT systems within the spa facilities, enabling real-time data acquisition via calibrated multi-parameter probes. Using data collected by these pilot systems, we develop and validate a predictive machine learning model capable of forecasting the short-term evolution of the thermal water properties. Historical data from each facility allow the model to learn the specifics dynamics of each spa. As a practical application, we propose an anomaly detection module based on residual analysis from predicted and observed values. Significant discrepancies signal events of interest and emergent trends, such as anomalous readings, contamination or sensor drift. The methodology is evaluated using real data from six spas associated with the AQUAPRED project. The results demonstrate the model’s effectiveness and support its feasibility for deployment in other thermal establishments. Full article

Water composition is a key factor influencing brewing performance and beer quality due to its impact on mash chemistry, fermentation kinetics, and fermentation-derived metabolites. This study evaluated the effect of four Albanian spring waters (Bogova, Germenji, Selita, and Lajthiza), each with distinct mineral compositions, on the fermentation behaviour and physicochemical characteristics of Pale Ale beer produced under standardised brewing conditions. All beers were brewed using the same malt formulation, hopping regime, yeast strain, and fermentation parameters, with water source as the sole experimental variable. The produced worts showed only moderate differences in pH, colour, extract, free amino nitrogen (FAN), bitterness, and density, whereas alcoholic fermentation proceeded efficiently in all treatments and was completed within seven days. Final alcohol contents ranged from 5.56 to 5.70% v/v, confirming comparable fermentation performance among treatments. More pronounced differences were observed in acidity-related parameters and fermentation-derived compounds. Volatile acidity ranged from 0.19 to 0.93 g/L, with the highest values in beers produced with Selita and Lajthiza waters. Glycerol concentrations varied from 0.88 to 1.24 g/L, with Germenji beer showing the highest value, whereas acetaldehyde ranged from 3.16 to 6.04 mg/L, with the lowest concentration in Germenji beer. Pearson correlation analysis and exploratory principal component analysis (PCA) identified associations between water mineralisation and selected physicochemical and fermentation-derived beer parameters. Calcium, magnesium, conductivity, and hardness were positively associated with glycerol concentration, whereas bicarbonate concentration was associated with beer pH and acidity-related parameters. The first two principal components explained 87.7% of the total variance. Overall, the results indicate that Albanian spring waters are suitable for Pale Ale production and show that differences in water mineral composition were associated with variations in the physicochemical and fermentation-derived characteristics of the final beers. These findings highlight that brewing water should not be regarded as a neutral processing medium but rather as an important technological factor associated with differences in the physicochemical characteristics of beer, while supporting the valorisation of Albanian spring waters for geographically distinctive craft brewing applications. Full article

Biomass thermochemical conversion-derived hydrochar has been increasingly recognized as a functional resource for environmental remediation, but knowledge about the effect of the carbonization conditions on the surface chemistry and binding behaviour of hydrochar is still limited. In this study, hydrochar from two different processing pathways, pressure reactor carbonization (P-RC) and microwave-assisted carbonization (M-RC), is compared to understand the mechanisms of contaminant interaction and the changes in structure that occur during the carbonization processing. P-RC was synthesized at the hydrothermal temperatures (180, 220, and 250 °C) for 2 and 5 h, while M-RC was synthesized at microwave irradiation for 30 min and 1 h. TGA, SEM–EDS, FTIR, and XRD were used for comprehensive characterization, which revealed systematic differences in functional group distribution, mineral phases, and microstructural development between the two carbonization methods and at different carbonization temperatures. The increase in P-RC temperature led to greater aromatic condensation, thermal stability, and mineral reorganization, while M-RC maintained a higher percentage of oxygenated functionality and a more heterogeneous surface morphology. Batch adsorption experiments indicated that the M-RC hydrochar had a faster adsorption rate, attributed to its greater number of reactive oxygenated functionalities, whereas the P-RC hydrochar produced at higher temperatures exhibited a more even distribution of adsorption sites and stronger mineral-assisted interactions. The kinetics and isotherm modeling also showed different interaction pathways: for M-RC, surface complexation on heterogeneous sites was favored, whereas for P-RC, a more monolayer-like adsorption was observed. These results collectively show how the method and temperature of carbonization affect reactivity and support the establishment of mechanistic relationships crucial to maximizing the utility of hydrochar as a functional material for environmental remediation. Full article

Marine by-products, including fishery discards, seafood-processing residues, aquaculture wastes, crustacean shells, and seaweed-derived side streams, are heterogeneous feedstocks rich in proteins, lipids, minerals, chitinous materials, polysaccharides, and bioactive compounds. This review examines insect-mediated bioconversion as a controlled biorefinery strategy for transforming these unstable marine residues into functional aquafeed ingredients and value-added bioproducts. We compare major marine feedstock classes and industrially relevant insects, with emphasis on substrate–insect matching, moisture control, salinity, lipid and ash load, texture, spoilage risk, and safety. Particular attention is given to how marine substrates can tailor insect meal, insect oil, chitinous fractions, hydrolysates, frass, and functional feed additives. The review further summarizes aquafeed applications of insect-derived products, including fishmeal and fish-oil replacement, protein and amino acid quality, lipid enrichment, gut health, immunity, and disease resistance in aquatic animals. Microbiome-assisted strategies, such as fermentation, enzymatic pretreatment, and gut or substrate microbial management, are discussed as tools to improve substrate stability, digestibility, and product quality. Finally, safety, regulation, scale-up, life cycle assessment, and techno-economic issues are considered. Overall, marine insect biorefineries should be optimized not only for biomass yield, but also for product quality, traceability, and application-specific safety. Full article

Granite is a major lithology of stone-built cultural heritage across East Asia, the Iberian Peninsula, the Indian subcontinent, Egypt and Italy. Long regarded as durable, it nonetheless undergoes mineralogical, microstructural and macroscopic alteration through pathways that are mechanistically universal yet regionally distinctive in expression. This review synthesizes granite weathering within a multianalytical framework spanning mineralogy, microstructure, geochemistry, environmental drivers and conservation science. Mineral-specific reactions—feldspar hydrolysis, biotite oxidation coupled to clay-mineral genesis, iron-bearing transformations driving surface coloration, quartz-mediated thermal microcracking and accessory-mineral pathologies—are examined as coupled processes governing macroscopic decay. A suite of complementary analytical methods, including non-destructive, minimally invasive and laboratory-based techniques, delivers mechanistic and prognostic resolution unattainable by any single method. Two case settings—the tenth-century rock-carved Buddhas of Gyeongju Namsan and the urban granite of Jongmyo Shrine, Seoul—illustrate how integrated diagnostics resolve coupled decay on natural outcrops and how cumulative atmospheric exposure is recorded in monument-scale fabrics. Chemical weathering indices, environmental controls and conservation implications are unified into a single framework, and key gaps—standardization, time-resolved diagnostics, climate projection, multi-omics coupling, consolidant durability and machine learning—are articulated as a research agenda for granite heritage science. Full article

Date syrup is a product processed from date (Phoenix dactylifera L.) flesh through a multi-unit operation process. This nutritious liquid is rich in carbohydrates, dietary fibres, polyphenols, minerals, and vitamins, and may provide functional and bioactive compounds with potential health-promoting properties. In this review, a summary of current literature related to the technological aspects of date syrup production was given with a focus on traditional, conventional, and novel extraction methods. Further, a systematic analysis of available data describing the compositional quality of date syrup based on biochemical, functional, antioxidant, and pro-healthy properties was highlighted. Finally, the potential applications of date-based syrup in several fields of food industry were discussed by highlighting the importance of using date syrup as an emerging alternative for sugar substitution in numerous food products and formulations. Full article

The growing demand for acrylic acid, driven by its widespread use in polymers and specialty chemicals, raises concerns regarding the environmental impact of its conventional fossil-based production. In this context, the present study evaluates the techno-environmental performance of a glycerol-based acrylic acid route compared to the conventional propylene pathway. Process simulations were carried out using CHEMCAD for an annual capacity of 50,000 tons. The environmental impact is assessed through Life Cycle Assessment (LCA) methodology and LCA for Experts software, following the ReCiPe 2016 (H) impact method. The results show that the glycerol-based route requires higher raw material input (1.90 kg/kg acrylic acid) than the propylene pathway (0.84 kg/kg acrylic acid), yet generates slightly lower liquid wastes (3.25 kg/kg acrylic acid vs. 3.60 kg/kg acrylic acid). From an environmental standpoint, the glycerol route performs better in 12 of 16 impact categories. The conventional process is dominated by the propylene supply chain, contributing up to 62% of the global warming impact, while electricity demand ranks second in the glycerol-based route. Scenario analysis based on future European electricity mixes (EU-2030 and EU-2050) further reduces climate and fossil depletion impacts, although with increased mineral resource use. Overall, the results highlight the potential of glycerol as an alternative feedstock and the key role of electricity sourcing. Full article

The increasing demand for seafood over the years has led to an increase in by-products produced by the seafood processing sector. These by-products, which can represent up to 70% of processed products, are rich in nutrients and bioactive compounds, allowing them to be used in several sectors, such as food, packaging, cosmetics and pharmaceutics, provided that recovery occurs in an eco-friendly manner. In the present work, two lactic acid bacteria (Lactobacillus lactis and L. brevis) and the yeast Yarrowia lipolytica, which are organisms capable of producing organic acids and proteases during the fermentation process, were used separately to extract chitin from deep-water shrimp (Aristeus antennatus) by-products. The results showed that L. lactis was the most effective microorganism in removing both the mineral and protein fractions; therefore, it was chosen to optimize the chitin extraction technique, after which chitin was eventually converted into chitosan. The obtained chitosan showed a deacetylation degree (DDA%) of 82%, indicating good film-forming capacity. The developed biological technique allowed the valorization of shrimp by-products by recovering chitin and eventually chitosan, allowing us to produce biofilms that could help prolong seafood shelf life and, from a circular economy point of view, contributing further to promoting the sustainability of the production sector. Full article

Mining of sulfide-rich deposits enhances the oxidation of sulfide minerals, generating acid mine drainage (AMD) characterized by high sulphate and dissolved metal concentrations and the formation of secondary iron minerals (hematite, goethite, and jarosite). As these minerals display diagnostic features in the visible–near-infrared (VNIR) region, multispectral satellite data provide a cost-effective means of monitoring. Here, the performances of Sentinel-2 and the VNIR bands from WorldView-3 are assessed and compared for the mapping and discrimination of secondary iron minerals in Sierra Minera de Cartagena–La Unión (SE Spain). Both datasets were analyzed using a band ratio and a parabola fitting technique focused on reflectance maxima. Band ratio results were interpreted as broad spectral patterns rather than definitive mineral identifications. Mineral maps were validated by applying X-ray diffraction on 74 surface soil samples. Although both sensors were able to reproduce the main spatial patterns of iron mineral distribution, Sentinel-2 data better discriminated hematite, goethite, and jarosite, especially when using the parabola fitting approach, whereas WorldView-3 VNIR data distinguished mainly hematite from the combined goethite–jarosite group. The better performance of Sentinel-2 is attributed to its red-edge and near-infrared band configuration. These findings indicate that freely available Sentinel-2 imagery can support systematic monitoring of oxidation processes in mining environments and contribute to environmental risk assessment in degraded landscapes. Full article

The Alappuzha district in Kerala, India, has large deposits of high-grade silica sand, which is mainly used for glass manufacturing. The primary objective of the study is to map these mineral deposits using multispectral satellite data and machine learning algorithms (MLAs). Moreover, detailed geochemical and structural characterisation was performed using Energy-Dispersive X-ray Fluorescence (ED-XRF) and X-ray diffraction (XRD), which confirmed the characteristics of the silica sand, with a SiO₂ content of 96.93–99.13%. The laboratory proximal spectra in the range of 400–2500 nm were processed and compiled as a reference spectrum for mapping using Landsat and ASTER remote sensing datasets. The support vector machine (SVM) outperforms other algorithms with an overall accuracy of 97.82%. Integrating remote sensing techniques, mineral characterization, and field data facilitates eco-friendly, sustainable mining of these strategic minerals. Full article

Chalcopyrite and molybdenite exhibit similar surface wettability and high floatability, which has long hindered their efficient and selective separation in mineral processing. In this work, the novel chalcopyrite depressant 2-mercapto-5-benzoimidazole sulfonate dihydrate (2MBI5SA) was investigated for its effect on the flotation behavior of chalcopyrite and molybdenite. Compared with the conventional depressant sodium sulfide (Na₂S), 2MBI5SA exhibited stronger selective depression toward chalcopyrite; under conditions yielding a Mo recovery of 81.46% and a Mo grade of 4.46%, the Cu recovery decreased to 13.03%. To clarify the origin of this selectivity, interfacial properties were systematically characterized using adsorption measurements, contact angle measurements, zeta potential measurements, FTIR, XPS, and SEM-EDS, and the adsorption mechanism was further elucidated using SCC-DFTB calculations. The results demonstrate that 2MBI5SA chemisorbs onto the chalcopyrite surface via bidentate coordination, forming a stable adsorption layer that effectively suppresses chalcopyrite flotation. Moreover, structure−function relationship analysis confirmed that introducing hydrophilic and ionizable functional groups into the collector framework can convert a collector into a selective depressant, thereby providing new insights into the rational design of selective organic depressants with potential environmental advantages over conventional highly toxic inorganic depressants. Full article

The Shaximiao Formation in the Sichuan Basin possesses favorable exploration potential for unconventional oil and gas, whereas systematic studies on the genetic mechanism of its tight sandstone reservoirs remain insufficient. In this study, tight sandstones of the study area were comprehensively investigated through multiple analytical methods, including thin section observation, scanning electron microscopy, cathodoluminescence, electron probe microanalysis, fluid inclusion testing, and reservoir physical property measurement. The Shaximiao Formation belongs to typical low-permeability tight reservoirs, which are predominantly composed of lithic arkose, followed by feldspathic litharenite and arkose. A variety of authigenic minerals are widely developed in the reservoirs, including laumontite, calcite, quartz overgrowth, feldspar overgrowth, and clay minerals. The main reservoir spaces consist of primary pores, feldspar dissolution pores, and laumontite dissolution pores. The reservoirs have reached middle diagenetic stage A. A full set of diagenetic events can be identified in the study interval. These processes consist of gypsum cementation, chlorite cementation, feldspar dissolution, quartz overgrowth, kaolinite precipitation, laumontite cementation and dissolution, carbonate cementation, and pyrite cementation. Synthetic analysis of microscopic inclusion occurrences, homogenization temperature, and salinity data reveals that the Shaximiao Formation experienced three successive charging episodes of three different fluid endmembers, namely indigenous formation brine, organic acid fluid, and low-salinity surface-derived fluid. These multiphase mixed fluids sequentially altered authigenic minerals and pore spaces under variable open–closed diagenetic systems. The diagenetic system evolved progressively from an early closed environment dominated by laumontite precipitation to a middle–late semi-open-to-open environment dominated by calcite and siliceous cementation. Differential fluid migration controls diagenetic processes and the spatial distribution of cements, which fundamentally accounts for the strong heterogeneity of the reservoirs. Three types of diagenetic environments are classified in the study area, namely compaction-dominated, cementation-dominated, and dissolution-dominated environments, which jointly control the diagenetic assemblages and physical property evolution of the reservoirs. Compaction acts as the primary pore-reducing factor, causing a total porosity loss of 23.34%. Dissolution of feldspar and laumontite serves as the major pore-enhancing process, increasing the porosity by 5.26% and 4.32%, respectively. The mudstone and carbonate rock fragments in western Sichuan provide essential materials for calcite cementation, while intermediate-acid pyroclastics and plagioclase albitization collectively promote laumontite enrichment. The infiltration of meteoric freshwater and the upward migration of organic acids along faults induce feldspar dissolution, further resulting in the formation of kaolinite and quartz overgrowths. The brackish diagenetic environment under arid climatic conditions facilitates the development of early gypsum, which is finally transformed into anhydrite through burial dehydration. Full article

Phenolic compounds represent a class of highly toxic, bioaccumulative, and persistent pollutants in industrial wastewater. Conventional treatment methods often fail to degrade these recalcitrant pollutants efficiently. Advanced oxidation processes, particularly semiconductor-based heterogeneous photocatalysis utilizing titanium dioxide (TiO₂), have exhibited highly effective strategies for complete pollutant mineralization. Pristine TiO₂ is a widely utilized photocatalyst. However, it is severely constrained by its wide band gap (active only under UV light) and rapid electron–hole recombination rate, restricting its efficiency under visible light for practical applications. Surface modification using iron (Fe) doping and reduced graphene oxide (rGO) coupling with TiO₂ has emerged as a promising strategy to overcome these challenges. Thus, this review evaluates the latest advancements in Fe-TiO₂ and rGO-TiO₂ photocatalysts for phenolic wastewater treatment. The fundamental photocatalytic mechanisms of TiO₂, binary (Fe-TiO₂ and rGO-TiO₂), and ternary (Fe-TiO₂/rGO) composites are examined. Additionally, it evaluates various synthesis techniques, including green synthesis routes, characterization techniques, prospects of Fe and rGO, and real-world application efficacy. Furthermore, a comparative performance matrix evaluates the performance progression from pristine TiO₂ to binary systems, and ultimately to ternary Fe-TiO₂/rGO composites. The ternary configuration exhibits remarkable synergy effects, where iron doping shifts the optical absorption into the visible light spectrum, and rGO acts as an electron sink to suppress recombination. Moreover, the long-term stability and reusability performance, toxicity, commercial capability, and life cycle assessment of the photocatalysts are discussed. Finally, the performance of these composites in real wastewater matrices was examined to determine the gap between laboratory success and industrial viability. Full article

The Casas Novas gold deposit is located in the Escoural Gold District of the Ossa Morena Zone (OMZ, SW Iberia) and consists of an orogenic gold system characterized by structurally controlled mesothermal lodes, which are related to a major shear zone. The mineralization shows evidence of two distinct metallogenic phases during regional metamorphism: (i) an early higher-temperature stage marked by Co-Ni-rich loellingite hosting Au-(Ag) alloys accompanied by pyrrhotite, and (ii) a later low-temperature stage with arsenopyrite, gold, maldonite and Bi-Te sulfosalts. Detailed textural analysis documents the evolution from initial Au-Ag alloys enclosed in Co-Ni-rich loellingite to subsequent Au-Bi-Te phases and newly formed arsenopyrite. The results show the thermal and chemical changes in the system, demonstrating the importance of fluid–rock interactions in the redox conditions, which became more oxidized, controlling the gold deposition. The comprehensive overview of the processes that led to the concentration of gold in the Casas Novas deposit provides a valuable contribution to the ongoing studies into the auriferous region of the Escoural Gold District. Full article