Search Results (4,121)

Laboratory incubation experiments were conducted to investigate the effects of coal fly ash (FA) amendment (0%, 2.5%, 7.5%, and 15%) and moisture regimes (40%, 70%, and 100% water holding capacity (WHC)) on the mineralization of carbon (C) in an acidic agricultural soil. The results showed that the soil C mineralization intensity initially increased and subsequently decreased throughout the incubation period, with the mineralization dynamics well described by the first-order kinetic model (0.9633 ≤ R² ≤ 0.9972). Carbon mineralization increased with the application rate of FA, while moisture effect followed the order 70% WHC > 100% WHC > 40% WHC. Indicators showing highly significant correlations with total C mineralization amount included FA application rate, pH, water-soluble organic carbon, (WSOC) and cellulase (CEL) activity. Specific bacterial (Acidobacteriota, Gemmatimonadota, Pseudomonadota, and Actinobacteriota) and fungal phyla (Chytridiomycota, Glomeromycota, and Olpidiomycota) exhibited stronger correlations with C mineralization. The microbial taxa exhibiting significant responses to FA and moisture conditions were not consistent. Although the addition of high proportions of FA, especially with adequate moisture conditions, can enhance soil microbial activity and C mineralization, the potential risks of soil C loss and the accumulation of toxic elements necessitate the prudent implementation of elevated FA application rates in practical scenarios. Full article

Almond hulls and shells, the byproducts of the almond industry, were analyzed to assess their potential valorization pathways. Shells showed a higher content in lignin and polysaccharides, but very low levels of extractives and inorganics. Hull’s high polar extractives fraction showed poor phenolic preponderance and antioxidant activity, but high sugar and mineral contents, and its lipophilic extracts were highly enriched in triterpenes (from 73.5% to 91.3%), while shells presented more fatty acids (27.4% to 34.2%) and sterols (17.4% to 29.1%). Shells exhibited much higher S/G ratio (syringyl to guaiacyl units) in their lignin polymer (1.0 to 1.4), compared to hulls (0.5 to 0.6). After mineral analyses, hulls showed high amounts of potassium (3.7–4.9%). Fixed carbon content was similar for both materials, but shells showed a higher energetic content, ~20 MJ/kg. Finally, both hulls and pellets increased the water holding capacity (WHC) of the soil by 50%, when added in weight percentages of 6.25% (hulls) and 25% (pellets). With these results, the range of possibilities for these waste materials is exciting: shells could be used to obtain hemicellulose oligosaccharides, while hulls could be used in sugar extraction for biotransformation or as a soil amendment. Full article

Microwave-induced oxidation has emerged as an effective approach for water purification. In this study, bismuth ferrite-supporting carbon nanotubes with strong microwave absorption and magnetism were successfully fabricated for the degradation of brilliant green. The reactivity of bismuth ferrite in microwave fields and the role of carbon nanotubes was revealed by systematic characterization methods. Our results demonstrated that the addition of bismuth ferrite in microwave-induced system can enhance the ability of microwave-induced absorption and further induce the degradation and mineralization of brilliant green within 10 min, significantly surpassing conventional heating methods. The brilliant green decomposition by bismuth ferrite in microwave-induced process is a heterogeneous process. Its excellent performance achieved by active species-trap experiments can be attributed to microwave-induced holes. Overall, this study presented a promising material for microwave-induced elimination of brilliant green and other dyes in aqueous media, which can provide the basis for the environmental application of microwave radiation to water purification and wastewater treatment. Full article

Peatlands are vital carbon reservoirs, but their ecological roles are increasingly being compromised by land use change. While tropical peatlands are often associated with lowlands, distinct highland peatlands also occur, they remain insufficiently explored. The Humbang Hasundutan peatlands formed on the southern flank of the Toba caldera following the ~74 ka super-eruption, where persistent waterlogging in cool, wet uplands enabled accumulation of predominantly woody peats. This study investigated the effects of recent land use changes on the chemical and biological properties of peat soils in Humbang Hasundutan (elevation 1350–1430 m.a.s.l.), comparing forests, open lands, and cultivated areas. Soil samples were collected from three sub-districts (Dolok Sanggul, Pollung, Lintong Nihuta) at two depths (10 cm and 40 cm) and analysed for carbon (C), nitrogen (N), pH, and microbial respiration. Results revealed the significant degradation in cultivated lands, with C content dropping to 10–15%, compared to 57.30% in forests. Nitrogen levels were highest in Dolok Sanggul (1.38% in cultivated land) and Pollung (1.32% in open land). C:N ratio varied from 66 in forests to 34 in cropping lands. Soil pH varied by land use, with cultivated areas showing elevated pH (5.09) due to mineral soil mixing, while natural forests retained acidic conditions (pH 3.9–4.4). Microbial respiration was highest in forests (5.49 mg CO₂/day) but decreased in disturbed areas. These results stress the climate-mitigation value of intact highland peat forests and the urgency of tailored restoration via rewetting and native revegetation, alongside cautious agroecological management. Full article

The Permian Xiashihezi Formation in the Ordos Basin is a typical tight sandstone gas reservoir, which is characterized by low porosity and strong heterogeneity. Diagenesis plays a crucial role in controlling reservoir quality. However, the multiple phases and types of diagenetic processes throughout geological history make the compaction mechanisms highly complex. This study employed a high-temperature and high-pressure diagenesis simulation system to conduct geological simulation experiments. Typical reservoir samples from the 2nd Member of the Permian Xiashihezi Formation were selected for these simulations. The experiments replicated the diagenetic evolution of the reservoirs under various temperature, pressure, and fluid conditions, successfully reproducing the diagenetic sequences. The diagenetic sequence included early-stage porosity reduction through compaction, early carbonate cementation, quartz overgrowth, chlorite rim formation, feldspar dissolution, and late-stage illite and quartz cementation. Mechanical compaction is the primary factor reducing reservoir porosity, exhibiting a distinct four-stage porosity reduction pattern: (1) continuous burial stage (>4000 m); (2) stagnation stage of burial (3900 m–4100 m); (3) the secondary continuous burial stage (>5000 m); (4) tectonic uplift stage (3600 m). The experiments confirmed that the formation of various authigenic minerals is strictly controlled by temperature, pressure, and fluid chemistry. Chlorite rims formed in an alkaline environment enriched with Fe²⁺ and Mg²⁺ (simulated temperatures of 280–295 °C), effectively inhibiting quartz overgrowth. Illite appeared at higher temperatures (>300 °C) in platy or fibrous forms. Feldspar dissolution was noticeable upon injection of acidic fluids (simulated organic acids), providing material for authigenic quartz and kaolinite. The key mineral composition significantly impacts reservoir diagenesis. The dissolution released Mg²⁺ and Fe²⁺ ions, crucial for forming early chlorite rims in the overlying sandstones, confirming the importance of inter-strata interactions in “source-facies coupling.” Through physical simulation methods, this study deepened the understanding of the diagenetic evolution and compaction mechanisms of tight sandstones. This provides significant experimental evidence and theoretical support for predicting “sweet spot” reservoirs in the area. Full article

Zibai Jade is a recently identified hydrogrossular-dominant jade originating from Shaanxi Province, China. It constitutes a polymineralic aggregate composed predominantly of hydrogrossular, with minor proportions of vesuvianite, diopside, chlorite, uvarovite, and calcite. A multi-method analytical approach was employed to characterize this jade, incorporating conventional gemological testing, polarizing microscopy, SEM, XRD, BSE, XRF, and EPMA, as well as UV-Vis and infrared (IR). These techniques enabled a detailed examination of its mineralogy, surface features, and color origin. The stone displays a heterogeneous color distribution, featuring a base hue of light green to yellowish-green, accompanied by distinct occurrences of emerald-green spots, dark green spots, mossy green inclusions, white patches, white veinlets, and a black dot with a green ring. Microanalytical results indicate that the emerald-green spots are principally composed of uvarovite; the dark green spots are dominated by hydrogrossular, diopside, and chlorite; fibrous green inclusions consist mainly of chlorite and Cr-bearing grossular; white patches and veinlets are primarily composed of calcite; and the black dot with a green ring predominantly comprises chromite and uvarovite. Coloration is attributed to the combined influence of Fe and Cr³⁺. The formation of Zibai Jade involved three mineralization stages: deposition of a carbonate protolith, high-temperature metasomatism, and retrograde alteration. The metasomatism was driven by hydrothermal fluids derived from granodioritic and ultramafic rocks, which provided Si, Al, and the essential Cr, respectively. The interplay of these processes resulted in the development of Zibai Jade, which exhibits a dense texture and attractive coloration. Full article

Multi-centennial C budgets in forested watersheds require information on forest growth, detritus turnover, and disturbances, as well as the transfer to and fate of terrestrial C in aquatics systems. Here, a sediment gravity core was collected from a drinking water reservoir in Canada, and analyzed for temporal changes in charcoal, magnetic susceptibility, carbon, and nitrogen. These indicators were used to assess disturbance history and terrestrial C sequestration in sediments. During the reservoir development period from 1910 to 2012, charcoal flux and magnetic susceptibility increased ca. 10 years after nearby fire and forest-clearing events associated with reservoir expansion. Total C and δ¹³C gradually declined during the development period, likely due to increased inputs of mineral soil from human activity. Concurrently, total terrestrial C sequestered in sediments, estimated using three or eight marker compounds, ranged between 3557 and 5145 Mg C/100 yrs, accounting for 11%–17% of DOC exports to the reservoir (30,640 Mg C/100 yrs), as estimated from a previously developed terrestrial carbon budget model. In comparison, mixed-severity fires burned around the reservoir during the pre-development period (pre-1910), as evidenced by stand ages and/or increases in charcoal flux. In general, decreased terrestrial C flux was associated with higher-severity fires that burned between 1870 and 1890 and perhaps around 1790. Further, comparisons show that soil erosion was up to 3× greater in the development versus the pre-development period. Overall, this investigation revealed the impact of land use change and fire on watershed carbon budgets and advanced a previously developed pyGC-MS methodology that demonstrated the amount of terrestrial and aquatic C being buried in sediment. It also identified the fraction of terrestrial C that was exported from the forest to the reservoir and sequestered in the sediment, uncommon data that could inform current and future landscape C budget modelling studies in this region. Full article

Organic manure and grass mulching are widely recognized as modifiers of soil microbial communities and nutrient dynamics; however, the combined effects of these practices on nitrogen fractionation and microbial functionality in orchard ecosystems remain poorly understood. This study conducted a comprehensive evaluation of soil nitrogen fractions, enzymatic activity, microbial diversity and functional traits in walnut orchards under three management practices: organic manure (OM), grass mulching combined with manure (GM), and chemical fertilization (CF) in China’s Loess Plateau. The results revealed that OM and GM significantly enhanced soil nutrient pools, with GM elevating total nitrogen by 1.96-fold, soil organic carbon by 97.79%, ammonium nitrogen by 128%, and nitrate nitrogen by 54.56% relative to CF. Furthermore, the OM significantly increased the contents of total hydrolysable nitrogen, amino sugar nitrogen, amino acid nitrogen, ammonia nitrogen, hydrolysable unidentified nitrogen, non-acid-hydrolyzable nitrogen compared to the CF and GM treatments. Meanwhile, ASN and AN had significant effects on mineral and total nitrogen. The OM and GM had higher activities of leucine aminopeptidase enzymes (LAP), α-glucosidase enzyme, β-glucosidase enzyme (βG), and N-acetyl-β-D-glucosidase enzyme (NAG). Microbial community analysis revealed distinct responses to different treatments: OM and GM enhanced bacterial Shannon index, while suppressing fungal diversity, promoting the relative abundance of copiotrophic bacterial phyla such as Proteobacteria and Chloroflexi. Moreover, GM favored the enrichment of lignocellulose-degrading Ascomycota fungi. Functional annotation indicated that Chemoheterotrophy (43.54%) and Aerobic chemoheterotrophy (42.09%) were the dominant bacterial metabolic pathways. The OM significantly enhanced the abundance of fermentation-related genes. Additionally, fungal communities under the OM and GM showed an increased relative abundance of saprotrophic taxa, and a decrease in the relative abundances of potential animal and plant pathogenic taxa. The Random forest model further confirmed that βG, LAP, and NAG, as well as Basidiomycota, Mortierellomycota, and Ascomycota served as pivotal mediators of soil organic nitrogen fraction. Our findings demonstrated that combined organic amendments and grass mulching can enhance soil N retention capacity, microbial functional redundancy, and ecosystem stability in semi-arid orchards. These insights support the implementation of integrated organic management as a sustainable approach to enhance nutrient cycling and minimize environmental trade-offs in perennial fruit production systems. Full article

Well cementing is an important step in oil and gas development. It uses cement to seal the formation and the casing, preventing fluid leakage. However, when conducting offshore oil well cementing operations, deep-water formations are usually weakly consolidated soils, and it is difficult to form a good cementation between the cement and formation. Therefore, enhancing the strength of the formation is one of the effective measures. This study uses the microbial-induced carbonate precipitation technology to cement sandy formations containing clay minerals. The triaxial tests were conducted to evaluate the consolidation effectiveness in the presence of three clay minerals: montmorillonite, illite, and kaolinite. X-ray computed tomography was utilized to characterize microscopic pore parameters, while thermogravimetric analysis, X-ray diffraction, and surface potential measurements were applied to analyze the mechanisms of clay minerals affecting microbial consolidation. The results showed that microbial mineralization mainly affects the cohesion of the samples. The cohesion of the montmorillonite sample increased from 20 kPa to 65.4 kPa, an increase of up to 3.27 times. The other two samples (illite and kaolinite) had increases of only 0.33 times and 1.82 times. Although the strength of the montmorillonite sample increased the most, unexpected large pores appeared with a diameter of over 120 µm, accounting for 7.1%. This is mainly attributed to the mineral expansion property. The expansion of the minerals will trap more microorganisms in the sample, thereby generating more calcium carbonate. And it also reduced the gaps between sand particles, creating favorable conditions for the connection of calcium carbonate. Although the surface charge of the minerals also affects the attachment of microorganisms, all three minerals have negative charges and a difference of no more than 0.84 mV (pH = 9). Therefore, the expansion property of the minerals is the dominant factor affecting the mechanical and microstructure of the sample. Full article

Detailed description of phase composition and geochemistry of the Muschelkalk carbonate rocks of the Upper Silesian Province in Poland were presented in this article. The tests were carried out to determine mineralogical features and geochemical properties. The samples were collected from the formations of the Lower Muschelkalk (Gogolin Unit), Middle Muschelkalk (Diplopore Dolomite Unit) and Upper Muschelkalk (Tarnowice Unit, Boruszowice Unit). The following research methods were used: macroscopic description, X-Ray Diffraction, Fourier transform infrared spectroscopy, X-Ray Fluorescence and Atomic spectrometry with plasma intensification. The following carbonate phases were identified: a low-Mg calcite, a high-Mg calcite, a proto-dolomite, an ordered dolomite and a huntite. The results of XRD analysis allowed the determination of the chemical formulas of the mineral phases. XRF and ICP AES analyses allowed to establish the content of following trace elements: Sr, Ba, Al, Si, Fe, Mn, K, Na, S, Cl, Ti, Cr, Ni, Zn, Rb, Zr, Pb, As, V, Be, B, Co, Cu, Br, Mo and Cd. Apart from Sr and Ba, they are not fundamental components of carbonate rocks. They indicate the presence of minerals such as silicates, aluminosilicates, oxides and sulfides. Full article

Pistachio (Pistacia vera L.) holds significant importance due to its diverse applications and nutritional benefits. The nuts are rich in essential amino acids, antioxidants, fiber, healthy fats, and minerals, making them highly valuable for human nutrition. However, pistachios are significantly challenged by salinity stress, which negatively affects their growth and metabolism. Understanding the impact of salinity stress on pistachios is crucial for developing effective strategies to enhance their tolerance, improve growth, and ensure sustainable production in saline environments. To investigate the effects of salinity on energy metabolism and amino acid composition, we monitored key metabolites and free amino acid levels in UCB-1 pistachio leaves at 7- and 21-day salt stress treatments using Liquid Chromatography–Mass Spectrometry (LC-MS) and Ultra Performance Liquid Chromatography (UPLC). Our findings revealed that salinity affected nearly all analyzed metabolites, with varied patterns observed at different time points. Notably, all free amino acids except threonine accumulated significantly in response to salt stress. Meanwhile, reductions in 3PGA, Fru1,6bP, and Glu6P+Fru6P (glycolysis and Calvin cycle intermediates) suggest a decrease in photosynthetic activity, which may ultimately impact respiration rates. These results demonstrate that salinity stress affects both amino acid metabolism and central carbon metabolism, with the magnitude and pattern of these changes depending on the duration of exposure. The observed metabolic adjustments likely represent an adaptive response, enabling the plant to partially mitigate the detrimental effects of salt stress. Full article

Mineral water content strongly depends on the geologic layer characteristics. Therefore, the aim of the present study is to make a comparison between two renowned mineral water sources in Romania, Borsec and Tusnad. Two public springs were selected from each location: Boldizsar (about 6600 L/day) and Lazar (about 500 L/day) from Borsec and Mikes (about 5000 L/day) and Young’s spring (about 600 L/day) from Tusnad. All investigated springs are naturally carbonated. Water properties were measured in situ and in laboratory for the collected samples; the results found that Borsec mineral water has a pH of about 7.5, while Tusnad mineral water is slightly acid (pH = 6.5). TDS strongly depends on the spring’s flow (for instance, Boldizsar has a TDS of about 900 mg/L, while Lazar has a TDS of about 1529 mg/L due to its high mineralization, while Young’s spring has a TDS of 165 mg/L due to its low mineralization, although it has low flow). Borsec mineral water has a lower salinity of about 1.22 PSU, while Tusnad water has a salinity of about 2 PSU, caused by a high amount of Na and Fe ions. Mineral waters dissolve ions from the geological layers, which react with carbonic acid during drying, generating specific crystallized compounds. The crystallized matter was investigated using XRD coupled with mineralogical optical microscopy (MOM); their microstructural features were observed using SEM coupled with elemental spectroscopy. Borsec water generates mainly Ca, Mg, and Na minerals like calcite, aragonite, pseudo-dolomite, natron, and traces of halite. Tusnad mineral waters have significant amounts of Ca, but also have Fe and much more Cl, since calcite and aragonite are mixed up with large amounts of halite and iron compounds. It looks like the presence of iron ions in the Tusnad mineral water collected from Mikes and Young’s spring explains the acidic pH. All these aspects are useful for further investigation regarding specific therapeutic purposes like chronic colitis and biliary lithiasis symptom amelioration (Boldizsar), chronic colitis, and enterocolitis symptoms (Lazar). Tusnad waters, like the water from Mikes spring, are recommended for anemia and neurasthenia, while Young’s spring is recommended for renal lithiasis amelioration. Full article

The rapid rise in atmospheric CO₂ concentrations has intensified the need for scalable, sustainable, and economically viable carbon sequestration technologies. This study introduces a cost-effective CaO/Ca(OH)₂-based mineralization process that not only enables efficient CO₂ removal but also allows the simultaneous recovery of high-purity calcite nanoparticles as value-added products. The process involves hydrating CaO, followed by controlled carbonation under optimized CO₂ flow rates, temperature conditions, and and additive use, yielding nanocrystalline calcite with an average particle size of approximately 100 nm. Comprehensive characterization using X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy confirmed a polycrystalline structure with exceptional chemical purity (99.9%) and rhombohedral morphology. Techno-economic analysis further demonstrated that coupling CO₂ sequestration with nanoparticle production can markedly improve profitability, particularly when utilizing CaO/Ca(OH)₂-rich industrial residues such as steel slags or lime sludge as feedstock. This hybrid, multi-revenue strategy—integrating carbon credits, nanoparticle sales, and waste valorization—offers a scalable pathway aligned with circular economy principles, enhancing both environmental and economic performance. Moreover, the proposed system can be applied to CO₂-emitting plants and facilities, enabling not only effective carbon dioxide removal and the generation of carbon credits, but also the production of calcite nanoparticles for diverse applications in agriculture, manufacturing, and environmental remediation. These findings highlight the potential of CaO/Ca(OH)₂-based mineralization to evolve from a carbon management technology into a platform for advanced materials manufacturing, thereby contributing to global decarbonization efforts. Full article

This study examines the pigments and materials used in Girolamo Romanino’s Musicians fresco (1537–1538), located in the Duomo Vecchio in Brescia, with the aim of identifying and analyzing the artist’s colour palette. Ten samples of the pictorial layer and mortar were collected from two frescoes and characterized using microscopic and spectroscopic techniques. Confocal laser scanning microscopy (CLSM) was used to define the best positions where single-point, spectroscopic techniques could be applied. Raman spectroscopy and micro-Fourier transform Infrared spectroscopy (micro-FTIR) were used to detect pigments and organic binders, respectively. X-ray powder diffraction (XRPD) provided additional insights into the mineral composition of the pigmenting layers, in combination with environmental scanning electron microscopy equipped with energy-dispersive spectroscopy (ESEM-EDS). The analysis revealed the use of traditional fresco pigments, including calcite, carbon black, ochres, and copper-based pigments. Smalt, manganese earths, and gold were also identified, reflecting Romanino’s approach to colour and material selection. Additionally, the detection of modern pigments such as titanium white and baryte points to restoration interventions, shedding light on the fresco’s conservation history. This research provides one of the most comprehensive analyses of pigments in Romanino’s works, contributing to a deeper understanding of his artistic practices and contemporary fresco techniques. Full article

Global urbanization has led to massive generation of high-water-content waste slurry, creating serious environmental challenges. Conventional treatment methods are costly and unsustainable, while cement-based foamed lightweight soils typically exhibit low strength and limited CO₂ sequestration. To address this issue, this study proposes a novel stabilization pathway by integrating a MgO–mineral powder–carbide slag composite binder with CO₂ foaming–carbonation. The approach enables simultaneous slurry lightweighting, strength enhancement, and CO₂ fixation. A series of laboratory tests were conducted to evaluate flowability, density, compressive strength, and deformation characteristics of the carbonated lightweight stabilized slurry. Microstructural analyses, including SEM and XRD, were used to reveal the formation of carbonate phases and pore structures. The results showed that MgO content strongly promoted carbonation, leading to denser microstructures and higher strength, while mineral powder and carbide slag optimized workability and pore stability. Orthogonal testing indicated that a mix with 25% mineral powder, 12.5% MgO, and 7.5% carbide slag achieved the best performance, with unconfined compressive strength up to 0.48 MPa after carbonation. Compared with conventional cement- or GGBS-based foamed lightweight soils, the proposed system exhibits superior strength development, improved pore stability, and enhanced CO₂ sequestration potential. These findings demonstrate the feasibility of recycling high-water-content waste slurry into value-added construction materials while contributing to carbon reduction targets. This study not only provides a sustainable solution for waste slurry management but also offers new insights into the integration of CO₂ mineralization into geotechnical engineering practice. Full article