Search Results (8,073)

This study presents an integrated approach to processing the heavy fraction of coal tar (HFCT) using oil shale (OS) from Shubarkol Komir JSC to simultaneously increase the yield of valuable hydrocarbon fractions and extract rare and dispersed trace elements. The lack of data on the effect of shale on the process and the kinetics of multi-component “tar + shale” systems limits the development of effective technologies. TG/DTG analysis was combined with the Friedman, Ozawa–Flynn–Wall, and Šesták–Berggren methods for the first time to evaluate the role of oil shale (OS). It was shown that the addition of 13% OS provides a sustained reduction in activation energy (~85–86 kJ/mol) and optimal conditions for hydrometallization. At 420 °C, an initial H₂ pressure of 4 MPa, and a reaction time of 60 min, the yield of light fractions reaches 62.6%, and the solid residue concentrates Ti, Mo, Ge, and other rare and dispersed elements reach up to 66,000 g/t in total. The possibility of extracting Ge using the Purolite C100 sorbent has also been confirmed. The novelty of the study lies in demonstrating the donor–catalytic effect of shale and the practical prospects of solid residue as a secondary mineral raw materials. Full article

This study provides the first comprehensive multiscale evaluation of raw coconut fibers as biosorbents for crude oil removal, encompassing laboratory adsorption tests, mesoscale hydrodynamic simulations, and field trials in marine environments. Fibers were characterized by SEM, FTIR, XRD, XPS, and chemical composition analysis (NREL method), confirming their lignocellulosic nature, high lignin content, and functional groups favorable for hydrocarbon adsorption. At the microscale, a 2⁵⁻¹ fractional factorial design evaluated the influence of dosage, concentration, contact time, temperature, and pH, followed by kinetic and equilibrium model fitting and regeneration tests. Dosage, concentration, and contact time were the most significant factors, while low sensitivity to salinity highlighted the material’s robustness under marine conditions. Adsorption followed pseudo-second-order kinetics, with an equilibrium adsorption capacity of 4.18 ± 0.19 g/g, and it was best described by the Langmuir isotherm, indicating chemisorption and monolayer formation. Mechanical regeneration by centrifugation allowed for reuse for up to five cycles without chemical reagents, aligning with circular economy principles. In mesoscale and field applications, fibers maintained structural integrity, buoyancy, and adsorption efficiency. These results provide strong technical support for the practical use of raw coconut fibers in oil spill response, offering a renewable, accessible, and cost-effective solution for scalable applications in coastal and marine environments. Full article

Consumption of meat singed with non-standard fuels is a common practice in many low- and middle-income settings, yet it may introduce combustion-derived toxicants with serious health consequences. While the toxicological effects of pollutants such as polycyclic aromatic hydrocarbons and heavy metals are well documented, the specific impact of singed meat consumption on endocrine regulation remains poorly understood. Of particular concern is the reproductive hormonal network, which not only serves as a sensitive biomarker of systemic disruption but also represents an evolutionary safeguard of fertility and generational continuity. Our study addresses this knowledge gap using male Wistar rats fed for 90 days (week 0 to week 12) on diets containing increasing proportions (25%, 50%, 75%) of meat singed with firewood, liquefied petroleum gas (LPG), or tyres. Firewood- and tyre-singed meat induced dose- and source-dependent toxicity, including hepatocellular injury, impaired protein metabolism, elevated blood urea nitrogen and creatinine, organ hypertrophy, and pronounced oxidative stress. Hormonal analysis revealed reduced testosterone alongside increased FSH, LH, and prolactin, indicating hypothalamic–pituitary–gonadal axis disruption and reproductive risk. In contrast, LPG-singed meat caused only minor alterations. These findings highlight reproductive hormones as sensitive biomarkers, underscoring the health risks of singeing practices and their evolutionary implications for fertility and population fitness. Full article

The present investigation provides a comparative six-month analysis of atmospheric pollution by polycyclic aromatic hydrocarbons (PAHs) in the urban region of Opole, Poland. The study employs dual monitoring methods: traditional quartz filter-based active air sampling and active moss biomonitoring using Pleurozium schreberi, Sphagnum fallax, and Dicranum polysetum mosses. The experimental campaign took place from August 2021 to February 2022, spanning the autumn and winter seasons. PAH concentrations were measured using gas chromatography–mass spectrometry (GC-MS) following methodical sample extraction protocols. Filters documented transient air changes in PAHs, particularly high-molecular-weight (HMW) components such as benzo[a]pyrene (BaP), which exhibited considerable increases during the colder months due to heightened heating activities and less dispersion. The size of particles deposited on the filters varied from 0.16 to 73.6 μm, with an average size of 0.71 μm. Mosses exhibited cumulative uptake trends, with D. polysetum showing the greatest bioaccumulation efficiency, particularly for low- and medium-molecular-weight PAHs, followed by P. schreberi and S. fallax. Meteorological indices, including sun radiation and air temperature, demonstrated significant negative relationships with PAH buildup in mosses. Diagnostic ratio analysis verified primarily pyrogenic sources (e.g., fossil fuel burning), although petrogenic contributions were detected in D. polysetum, indicating its increased sensitivity to evaporative emissions. The study shows that the integration of moss biomonitoring with traditional filter samples provides a strong, complementary framework for assessing air quality, particularly in fluctuating meteorological settings. The results advocate for the integration of moss-based methodologies into environmental monitoring initiatives and provide significant insights into contaminant dynamics influenced by seasonal and meteorological factors. Full article

Crude oil exploration and transportation have led to significant soil contamination in nearby communities, yet seasonal and depth-related variations remain poorly understood. This study assessed physicochemical properties, potentially toxic elements, and polycyclic aromatic hydrocarbons in surface (0–15 cm) and subsurface (15–30 cm) soils from the Ibaa community and its pipeline Right of Way (ROW) in Rivers State, Nigeria. Samples were collected during wet and dry seasons from five locations, and analyses were conducted using standard methods. Results showed that soil temperature ranged from 27.5 to 31.2 °C, reflecting natural environmental conditions, while nitrate concentrations (1.23–3.45 mg/kg) and moisture content (14.3–23.9%) were within acceptable WHO limits. The pH values (4.61–5.72) suggested acidic conditions, particularly in the unremediated areas. Total Organic Carbon exceeded 3%, with a maximum of 6.23% recorded in the wet season, suggesting persistent hydrocarbon contamination. Phosphorus levels (2.65–6.02 mg/kg) were below the 15 mg/kg threshold. Notably, As (4.93 mg/kg) and Cd (1.67 mg/kg) concentrations exceeded the permissible WHO limits. Positive correlations were observed between As–Cd (r = 0.79), Cd–Cu (r = 0.85), and Pb–Cu (r = 0.64). Principal Component Analysis identified four components for physicochemical parameters (81.9% variance) and two for metals (82.6% variance), suggesting crude oil combustion and vehicular emissions as dominant pollution sources. Pb also correlated significantly with total PAHs in the dry season (r = 0.54, p < 0.05). The study highlights the influence of season and depth on contaminant behavior and emphasizes the urgent need for remediation and monitoring to mitigate ecological and public health risks. Full article

High-molecular-weight polycyclic aromatic hydrocarbons (PAHs), such as pyrene, are persistent environmental pollutants that threaten soil health and agricultural productivity due to their resistance to degradation. This study evaluated the efficacy of domesticated bacteria isolated from contaminated farmland soil and activated sludge, used alone and in combination with corn (Zea mays L.), to remove pyrene from soil, enhance plant growth, improve tolerance, and ensure crop safety. Six bacterial strains were isolated: three from polluted farmland soil (WB1, WB2, and WF2) and three from activated sludge (WNB, WNC, and WH2). High-throughput 16S rRNA amplicon sequencing profiled bacterial communities after 30 days of treatment. Analytical tools, including LEfSe, random forest, and ZiPi analyses, identified biomarkers and core bacteria associated with pyrene degradation, assessing their correlations with plant growth, tolerance, and pyrene accumulation in corn straw. Bacteria from activated sludge (WNB, WNC, and WH2) outperformed farmland soil-derived strains and the inoculant strain ETN19, with WH2 and WNC achieving 65.06% and 87.69% pyrene degradation by days 15 and 30, respectively. The corn–bacteria consortium achieved up to 97% degradation. Activated sewage sludge (ASS)-derived bacteria were more effective at degrading pyrene and enhancing microbial activity, while soil-derived bacteria better promoted plant growth and reduced pyrene accumulation in straw. Microbial communities, dominated by Proteobacteria, exhibited high species richness and resilience, contributing to xenobiotic degradation. The corn-domesticated bacteria consortia effectively degraded pyrene, promoted plant growth, and minimized pollutant accumulation in crops. This remediation technology offers a promising strategy for rapid and sustainable bioremediation of agricultural soils contaminated with organic compounds such as PAHs or other complex pollutants, while promoting the development of efficient bacterial communities that enhance crop growth. Full article

Welsh onion (Allium fistulosum L.) is a globally significant culinary vegetable with extensive cultivation and high application value. In China, Welsh onion is vulnerable to drought and strong-light stress in summer production, resulting in growth inhibition and quality decline. This study utilized LED-intelligent spectral-customized lamps to simulate high-light stress and a 10% PEG-6000 Hoagland solution to simulate drought stress. The effects of different stress treatments on the nutritional quality, volatile compounds, and mineral element composition of the edible portions were systematically analyzed. The results demonstrated that drought stress significantly promoted the accumulation of alcoholic compounds in leaf tissues while reducing the content of sulfur-containing compounds. High-light stress markedly increased the levels of hydrocarbon compounds in leaves. Sulfur-containing compounds in leaf tissues were predominantly disulfides, but under combined drought and high-light stress, their content decreased, while the proportion of trisulfides significantly increased. Volatile compounds in pseudostems were primarily composed of sulfur-containing and aldehyde compounds, yet their levels markedly declined under combined stress. Additionally, combined stress led to reductions in pyruvic acid, soluble sugars, and soluble protein content in the edible portions, while the crude fiber content increased, thereby significantly impairing nutritional quality. This study provides a scientific basis for understanding the abiotic stress response mechanisms of Welsh onion and offers valuable insights for cultivation management and quality regulation. Full article

Fracture systems critically govern coal seam permeability, influencing hydrocarbon migration pathways and well placement strategies. We established a predictive framework for fracture characterization in thin-interbedded coal reservoirs by integrating seismic response analysis with multi-domain validation. Utilizing borehole log statistics and staggered-grid wave equation modeling, we first decode azimuthal amplitude anisotropy patterns in fractured coal seams under varying lithological contexts. Key findings reveal that (1) isotropic thick surrounding rocks yield distinct fracture symmetry axis alignment (ellipse long-axis orientation shifts with layer velocity), while (2) anisotropic thin-interbedded host strata amplify azimuthal anisotropy ratios at mid–far offsets but induce prediction ambiguity under comparable fracture intensities. By applying azimuthally partitioned OVT data with optimized mid–long offset stacking, our amplitude ellipse fitting method demonstrates unique fracture solutions validated against structural, logging, and production data. This workflow resolves the multi-solution challenges in thin-layered systems, enabling precise fracture parameter prediction to optimize coalbed methane development in geologically complex basins. Full article

This study presents a comprehensive morphological and structural analysis of carbon materials produced via simple thermal methane pyrolysis conducted under laboratory conditions in a quartz reactor without the use of catalysts. The process, carried out at 1000 °C, achieved moderate methane conversion (36.5%), process efficiency (36.1%), and very high selectivity (98.9%) towards hydrogen production, highlighting its potential as a CO₂-free hydrogen generation method. Distinct carbon morphologies were observed depending on the formation areas within the reactor: a predominant flake-like silver carbon formed on reactor walls at temperatures between 600 and 980 °C (accounting for 91% of the solid product) and a minor powdery carbon formed near 980–1000 °C (9% of the solids). The powdery carbon exhibited a high specific surface area (125.3 m²/g), substantial mesoporosity (60%), and porous spherical aggregates, indicating an amorphous structure. In contrast, flake-like carbon demonstrated a low surface area (1.99 m²/g), high structural order confirmed by Raman spectroscopy, and superior thermal stability, making it suitable for advanced applications requiring mechanical robustness. Additionally, polycyclic aromatic hydrocarbons were detected in cooler zones of the reactor, suggesting side reactions in low-temperature areas. The study underscores the impact of temperature zones on carbon structure and properties, emphasizing the importance of precise thermal control to tailor carbon materials for diverse industrial applications while producing clean hydrogen. Full article

This study presents an integrated petrophysical workflow for the comprehensive characterization of the Upper Dalan and Kangan carbonate gas reservoirs in the Shanul Field, southwest Iran. By combining advanced cross-plot techniques (including M-N, MID, and RHOma-Uma plots) with probabilistic porosity modeling calibrated to core data, this work achieves a higher-resolution discrimination of lithology and more robust estimation of fluid properties compared to conventional single-log approaches. The results reveal significant heterogeneity within both formations but demonstrate the superior reservoir quality of the Upper Dalan, particularly within the UD2 subzone, and in the Ka-2a subzone of the Kangan. The improved workflow enables more accurate zonation and identification of high-quality, productive intervals, supporting optimized field development strategies. These findings provide methodological advances for challenging and heterogeneous carbonate systems, offering a reference framework for similar reservoirs in the Zagros Basin and beyond. Full article

Currently, the potential environmental concerns around the world for polycyclic aromatic hydrocarbon carcinogenic (PAHCs) contamination as carcinogenic compounds in industrial soils (automobile industry) are rising day by day. At present, the technology of treating contaminated soils using photocatalysts is commonly used; however, this study tested photolysis and photocatalysis through ultraviolet light (306 nm) due to its high treatment efficiency. FeCl₃ (0.3, 0.4 M) was used as an iron catalyst for each treatment in the presence of H₂O₂ (10%, 20%) as an oxidizing agent. The impact of light treatment on soils that contained various concentrations of PAHCs like naphthalene (NAP), chrysene (CRY), benzo(a) pyrene (BaP), indeno (1,2,3-cd) pyrene (IND) was investigated. The QuEChERS method was used to extract PAHCs, and a gas chromatograph mass spectrometer (GCMSMS) was used to determine concentration. The concentrations of PAHCs were measured for soils at intervals of every 2 h after exposure to ultraviolet rays. The results showed a decrease in PAHCs concentrations with increased exposure to UV irradiation, as the initial values were 26.8 ng/g (NAP), 97 ng/g (CRY), 9.1 ng/g (BaP) and 9.7 ng/g (IND), which decreased to 2.17 ng/g (NAP), 3.14 ng/g (CRY), 0.33 ng/g (BaP) and 0.46 ng/g (IND) at 20, 40, 30 and 40 h of UV exposure; moreover, with an increase in concentration of the catalyst (0.4 M FeCl₃ with 20% H₂O₂), NAP, CRY, BaP and IND became undetectable at 8, 26, 14 and 20 h, respectively. It was concluded that a significant effect of ultraviolet rays on the photolysis of PAHCs, along with Photovoltaic at 306 nm wavelength, was observed while using FeCl₃ (0.4 M) combined with H₂O₂ (20%) produced better results in a shorter time compared to FeCl₃ (0.3 M) with H₂O₂ (10%). Full article

Dry reforming of methane and ethanol is a promising catalytic process for the conversion of carbon dioxide and hydrocarbon feedstocks into synthesis gas (H₂/CO), which serves as a key platform for the production of fuels and chemicals. Over the past decade, substantial progress has been achieved in the design of catalysts with enhanced activity and stability under the demanding conditions of these strongly endothermic reactions. This review summarizes the latest developments in catalyst systems for DRM and EDR, including Ni-based catalysts, perovskite-type oxides, MOF-derived materials, and high-entropy alloys. Particular attention is given to strategies for suppressing carbon deposition and preventing metal sintering, such as oxygen vacancy engineering in oxide supports, rare earth and transition metal doping, strong metal–support interactions, and morphological control via core–shell and mesoporous architectures. These approaches have been shown to improve coke resistance, maintain metal dispersion, and extend catalyst lifetimes. The review also highlights emerging concepts such as multifunctional hybrid systems and innovative synthesis methods. By consolidating recent findings, this work provides a comprehensive overview of current progress and future perspectives in catalyst development for DRM and EDR, offering valuable guidelines for the rational design of advanced catalytic materials. Full article

Polymer-based product usage in modern society is increasing day by day. Following usage, these inert products and hydrophobic materials contribute to environmental pollution, often accumulating as litter in ecosystems and contaminating water bodies. The rapid socio-economic development in the Kingdom of Saudi Arabia (KSA) has resulted in a significant increase in waste generation. This study was conducted on the utilization of recycled plastic waste (RPW) polymer along with commercial polymer (CP) for the modification of the local binder. The hot environmental conditions and increased traffic loading are the major reasons for the permanent deformation and thermal cracks on the pavements, which require improved and modified road performance materials. The Ministry of Transport and Logistical Support (MOTLS) in Saudi Arabia, along with other related agencies, spends a substantial amount of money each year on importing modifiers, including chemicals, hydrocarbons, and polymers, for modification purposes. This research was conducted to investigate and utilize available local recycled plastic materials. Comprehensive laboratory experiments were designed and carried out to enhance recycled plastic waste, including low-density polyethylene (rLDPE), high-density polyethylene (rHDPE), and polypropylene (rPP), combined with varying percentages of commercially available polymers such as Styrene-Butadiene-Styrene (SBS) and Polybilt (PB). The results indicated that incorporating recycled plastic waste expanded the binder’s susceptible temperature range from 64 °C to 70 °C, 76 °C, and 82 °C. The resistance to rutting was shown to have significantly improved by the dynamic shear rheometer (DSR) examination. Achieving the objectives of this research, combined with the intangible environmental benefits of utilizing plastic waste, provides a sustainable pavement development option that is also environmentally beneficial. Full article

JP-10 (exo-tetrahydrodicyclopentadiene) is a high-energy-density hydrocarbon broadly used in advanced aerospace propulsion as a regenerative cooling fluid; in this study, we aimed to clarify how fuel pressure affects its thermal degradation (oxidative and pyrolytic) in near-isothermal flowing reactor. Experiments were performed under oxidative conditions (wall temperature 623.15 K, p = 0.708–6.816 MPa) and pyrolytic conditions (wall temperature 793.15 K, p = 2.706–7.165 MPa); carbon deposits were quantified by LECO analysis, oxidation activity was assessed by temperature-programmed oxidation (TPO), and morphology was performed by FESEM and EDS. Results show that oxidative coking is minimal (5.37–14.95 μg·cm²) and largely insensitive to pressure in the liquid phase (1.882–6.816 MPa), whereas at 0.708 MPa (gas/phase-change conditions), deposition increases, implicating phase and local heat-transfer effects. Under oxidative conditions, deposits are predominantly amorphous carbon with a disordered structure, formed at relatively low temperatures, with only a few fiber-like metal sulfides identified by EDS. In contrast, under pyrolysis conditions, the deposits are predominantly carbon nanotubes, exhibiting well-defined tubular morphology formed at elevated temperatures via metal-catalyzed growth. The pyrolysis coking yield is substantially higher (66.88–221.89 μg·cm⁻²) and increases with pressure. The findings imply that the pressure influences the coking of JP-10 via phase state under oxidative conditions and residence time under pyrolytic conditions, while basic morphologies of coke deposits remain similar; operationally, maintaining the working pressure higher than the saturated vapor pressure can mitigate oxidation coking associated with phase transitions, and minimizing residence time can mitigate pyrolytic coking. Full article

The review is focused on dictyopterenes A, B, C, and D found in marine algae, covering their (a) distribution; (b) methods of isolation and identification; (c) absolute configuration; and (d) biosynthesis considerations. Dictyopterenes A and B are usually present in high amounts in Dictyopteris spp. Dictyopterene A was found to be abundant in D. prolifera, D. undulata, D. latiscula, D. polypodioides, and D. membranacea. Dictyopterene B (hormosirene) was found as the major compound in D. plagiogramma, D. australis, Hormosira banksii, D. potatorum, D. willana, D. antarctica, Xiphophora chondrophylla, X. gladiata, Scytosiphon lomentaria, Colpomenia peregrina, and Haplospora globosa. Dictyopterene C (dictyotene) was a major compound in D. undulata, D. prolifera, D. membranacea, Gomphonema parvulum, Amphora veneta, Phaeodactylum tricornutum, and D. vermicularis. Dictyopterene D (ectocarpene) was present in Ectocarpus siliculosus, Analipus japonicus, D. prolifera, D. undulata, and Sargassum linifolium. The following enantiomers were found: (1S,2R)-dictyopterene A, (1R,2R)-dictyopterene B, (1S,2S)-dictyopterene B, (1S,2R)-dictyopterene B, (R)-dictyopterene C, and (S)-dictyopterene D. In marine algae, C₁₁-hydrocarbons are derived from C₂₀ polyunsaturated fatty acids by the oxidative cleavage via, e.g., 9-hydroperoxyicosa-(5Z,7E,11Z,14Z,17Z)-pentaenoic acid. An alternative biosynthetic pathway for dictyopterene A and B via the proposed intermediates (S)-dictyoprolenols was considered by oxidative cleavage of hydroperoxyicosatetraenoic acid. Full article