Aromatic Hydrocarbons Research Articles

Novel Aryl Hydrocarbon Receptor Agonists for Treating Psoriasis and Atopic Dermatitis

Novel Aryl Hydrocarbon Receptor Agonists for Treating Psoriasis and Atopic Dermatitis

Detectability of polycyclic aromatic hydrocarbons in the atmosphere of WASP-6 b with JWST NIRSpec PRISM

Abstract Polycyclic Aromatic Hydrocarbons (PAHs) have been detected throughout the universe where they play essential roles in the evolution of their environments. For example, they are believed to affect atmospheric loss rates of close-in planets and might contribute to the pre-biotic chemistry and emergence of life. Despite their importance, the study of PAHs in exoplanet atmospheres has been limited. We aim to evaluate the possibility of detecting PAHs on exoplanets considering future observations using JWST’s NIRSpec PRISM mode. The hot Saturn WASP-6 b shows properties that are consistent with a potential PAH presence and is thus used as a case study for this work. Here, we compare the likelihoods of various synthetic haze species and their combinations with the influence of PAHs on the transmission spectrum of WASP-6 b. This is possible by applying the atmospheric retrieval code petitRADTRANS to a collection of data from previous observations. Subsequently, by exploring synthetic, single transit JWST spectra of this planet that include PAHs, we assess if these molecules can be detected in the near future. Previous observations support the presence of cloud/haze species in the spectrum of WASP-6 b. While this may include PAHs, the current data do not confirm their existence unambiguously. Our research suggests that utilizing the JWST for future observations could lead to a notable advancement in the study of PAHs. Employing this telescope, we find that a PAH abundance of approximately 0.1percnt of the ISM value could be robustly detectable.

Geochemical characteristics of lacustrine source rocks and oil-source correlation of the Yanchang Formation in the Zizhou area, Ordos Basin

The Zizhou area on the northeastern margin of the Ordos Basin has achieved major breakthroughs through continuous exploration over the years, demonstrating high potential for hydrocarbon exploration. However, due to the underdevelopment of source rocks, the origin of crude oil in the Chang 6 and Chang 4 + 5 Members remains unclear, which significantly hinders further hydrocarbon exploration. In this study, we use Rock-Eval pyrolysis, kerogen maceral analysis, quantitative gas chromatography (GC) of saturated hydrocarbons, and GC-mass spectrometry of saturated and aromatic hydrocarbons to determine the geochemical characteristics of source rocks and oils from different sedimentary environments. In addition, we select effective biomarker parameters to identify the source of oil in the Chang 6 and Chang 4 + 5 Members in the Zizhou area. The results indicate that the Chang 7 Member source rocks have organic matter abundances ranging from good to excellent, with types classified as type I-II1, and are in a mature stage. Source rocks from the semideep to deep lacustrine facies exhibit a clear predominance of low-carbon number hydrocarbons, a higher proportion of short-chain n-alkanes, relatively lower C24 tetracyclic terpane/C26 tricyclic terpane (C24TeT/C26TT) and C30 hopane/C30 diahopane (C30H/C30DiaH) ratios, and similar abundances of C27 and C29 steranes. In contrast, deltaic facies source rocks, which developed in suboxic to oxic environments, display opposite characteristics. The reservoir extracts from the Zizhou area indicate a high degree of similarity to the deltaic facies source rocks. Moreover, the subtle geochemical differences between the reservoir extracts and their potential source rocks are mainly attributed to geochromatographic effect during hydrocarbon migration and differences in preservation conditions. These findings provide new insights into the dynamics of hydrocarbon migration and accumulation in the northeastern margin of the Ordos Basin and further reinforce the reliability of using biomarker techniques to determine the relationship between crude oil and its source.

Air pollution and skin aging

Air pollution is a leading environmental health risk worldwide, with detrimental effects not only on human health but also on skin aging. This review explores the link between air pollution and skin aging, focusing on the harmful effects of particulate matter (PM) and other pollutants such as polycyclic aromatic hydrocarbons (PAHs), nitrogen oxides (NO2), and ozone (O3). These pollutants penetrate the skin, inducing oxidative stress and inflammation, which accelerates the degradation of collagen and elastin in the extracellular matrix. This contributes to premature aging, wrinkles, hyperpigmentation, and inflammatory skin conditions. The smallest fractions of PM, particularly PM2.5, are the most harmful, causing significant cellular damage. Long-term exposure to these pollutants also disrupts the skin's microbiome, leading to dysbiosis and further weakening the skin's protective barrier. Current therapeutic strategies focus on protecting the skin using antioxidants, such as Vitamin C and Vitamin E, as well as probiotics and moisturizers that support the skin's natural defenses. Sunscreens also play a vital role in protecting the skin from UV-induced oxidative stress, further mitigating pollution-related damage. This review highlights the importance of developing comprehensive skincare regimens that target both pollution-induced oxidative stress and the maintenance of a healthy skin barrier. It also emphasizes the need for further research into personalized approaches to counteract the aging effects of air pollution on the skin.

Inhibition of Polycyclic Aromatic Hydrocarbons Formation During Supercritical Water Gasification of Sewage Sludge by H2O2 Combined with Catalyst

This work evaluated the alterations in the levels and types of polycyclic aromatic hydrocarbons (PAHs) within both liquid and solid products throughout the process of the catalytic supercritical water gasification of dewatered sewage sludge to examine the catalytic effect of various catalysts and the inhibit reaction pathways. The addition of Ni, NaOH, Na2CO3, H2O2, and KMnO4 reduced the concentrations of PAHs, with Ni and H2O2 showing the best performance. The concentrations of PAHs, especially higher-molecular-weight compounds in the residues, decreased sharply as the H2O2 amount increased. At a 10 wt% H2O2 addition, the levels of PAHs in the liquid and solid products were reduced by 91% and 88%, respectively. High-ring PAHs were not detected in the residues as the H2O2 amount increased to an 8 wt%. H2O2 addition evidently inhibits PAH formation by promoting the ring-opening reactions of initial aromatic compounds in raw sludge and inhibiting the polymerization of open-chain intermediate products. The addition of NaOH + H2O2 or Ni + H2O2 as combined catalysts significantly lowered PAH concentrations while increasing the H2 yield. The addition of 5 wt% Ni + H2O2 reduced PAH concentrations in the liquid and solid residues by 70% and 44%, respectively, while the H2 yield escalated from 0.13 mol/kg OM to 3.88 mol/kg OM. Possible mechanisms associated with the reaction pathways of these combined catalysts are proposed.

Vinylene‐Linking of Polycyclic Aromatic Hydrocarbons to π‐Extended Two‐Dimensional Covalent Organic Framework Photocatalyst for H2O2 Synthesis

AbstractPolycyclic aromatic hydrocarbons (PAHs) hold the predominant role either as individual molecules or building blocks in the field of organic semiconductors or nanocarbons. Connecting PAHs via sp2‐carbon bridges to form high‐crystalline π‐extended structures is highly desired not only for enlarging the regimes of two‐dimensional materials but also for achieving exceptional properties/functions. In this work, we developed 5,10‐dimethyl‐4,9‐diazapyrene as a key monomer, whose two methyl groups at the positions adjacent to nitrogen atoms, can helpfully increase the solubility, and serve as the active connection sites. In the presence of organic acids, this monomer enables smoothly conducting Knoevenagel condensation to form two vinylene‐linked PAH‐cored COFs, which show high‐crystalline honeycomb structures with large surface areas up to 1238 m2 g−1. Owing to the direct connection mode of PAH building blocks with vinylene, the as‐prepared COFs possess spatially extended π‐conjugation and substantial semiconducting properties. Consequently, their visible‐light photocatalysis with exceptional activity and durability was manifested to generate H2O2 up to 3820 μmol g−1 h−1 in pure water, and even 17080 μmol g−1 h−1 using benzyl alcohol as a hole sacrificial agent.

Recent Advances in the Cascade Cyclization of Alkyne Units for the Construction of Benzofluorenes

AbstractBenzofluorenes are an important class of polycyclic aromatic hydrocarbons (PAHs), which are widely used in materials science for light‐sensitive electronic components. In addition, the benzofluorene skeleton also serves as a key structural unit in various natural products. Therefore, the development of synthetic strategies for the construction of benzofluorenes has been a prominent research topic in synthetic chemistry. Over the past few decades, numerous efforts have been made for the construction of benzofluorenes via cascade cyclization of alkyne units. This review aims to summarize recent advances in the cascade cyclization of alkyne units for the construction of Based on the different reaction mechanisms underlying these transformations, this review can be divided into four categories: (1) thermal‐induced cascade cyclization of alkyne units for the construction of benzofluorenes, (2) metal‐catalyzed cascade cyclization of alkyne units for the construction of benzofluorenes, (3) acid‐promoted/catalyzed cyclization of alkyne units for the construction of benzofluorenes, and (4) base‐promoted cascade cyclization of alkyne units for the construction of benzofluorenes.

Exploring the possibility of polycyclic aromatic hydrocarbons and fulleranes as the carrier of the 21 micron emission feature

IntroductionThe 21 μm emission feature discovered in a small sample of carbon-rich protoplanetary nebulae has remained unidentified for over 30 years. A dozen of different molecular species (both organics and inorganics) have been proposed as the carrier candidates of this important feature, among which polycyclic aromatic hydrocarbons (PAHs) and fulleranes (hydrogenated fullerenes) have yet to be sufficiently examined.MethodIn this study, we attempt to fit the 21 μm features in observed spectra of the above-mentioned astronomical sources via theoretically simulated spectra of various PAHs and fulleranes, aiming to investigate whether the two hydrocarbon families can reproduce the 21 μm feature.Results and DiscussionBased on the fitting outcomes we conclude that fulleranes can provide a more plausible explanation for the origin of 21 μm feature than PAHs.

TMET-15. INVESTIGATING THE IL4I1-AHR AXIS IN GLIOBLASTOMA METABOLISM

Abstract Glioblastoma (GB) is the most frequent and malignant form of primary brain tumors in adults. Despite multi-modal therapy consisting of surgery, radio- and chemotherapy, tumors recur and overall survival remains poor. Previously, we identified that besides the classical tryptophan-catabolizing enzyme tryptophan-2,3-dioxygenase (TDO2), the L-amino acid oxidase interleukin-4-induced 1 (IL4I1) is able to activate the transcription factor aryl hydrocarbon receptor (AHR) via production of downstream metabolites. Activation of the AHR in GB may promote tumor progression e.g. by inhibiting anti-tumor immune responses. In this study, we aim to elucidate further the specific effects of the metabolic enzyme IL4I1 and its metabolites on AHR activation in GB. Further, we set out to identify and validate novel AHR target genes downstream of IL4I1. Harnessing the IL4I1-AHR axis might lead to the development of novel therapy strategies helping to overcome resistance in GB in the future.

IMMU-35. TARGETING THE AHR IMMUNOMETABOLIC HUB DURING VIROIMMUNOTHERAPY OF GLIOMAS

Abstract Glioblastoma (GBM) poses a significant therapeutic challenge in oncology. Recent clinical trials have shown the feasibility of virotherapy to treat patients with GBM. Our laboratory developed an oncolytic adenovirus termed Delta-24-RGD that has been tested in clinical trials for recurrent GBM patients with encouraging results (NCT00805376, NCT02798406). These clinical studies, together with preclinical data, showed that the efficacy of Delta-24-RGD was due to direct tumor cell oncolysis and indirect activation of anti-tumor immune response. To further leverage this immune component, our group generated Delta-24-RGDOX, an armed version of Delta-24-RGD expressing the T-cell activator OX40-L, which exhibits a superior anti-cancer effect. In this project, we aim to further boost the effectiveness of Delta-24-RGDOX by targeting factors that maintain the immunosuppressive characteristic of gliomas. Specifically, we identified the environmental sensor and transcription factor Aryl Hydrocarbon Receptor (AhR) as one of the immunosuppressive factors. We show that AhR is overexpressed in GBM surgical specimens compared to healthy brain tissue, and high AhR expression correlates with poorer survival in glioma patients. Immunofluorescence staining of glioma cells treated with Delta-24-RGDOX demonstrated that AhR translocates to the nucleus, and qPCR showed that translocation resulted in the enhanced transcription of AhR-responsive elements. Additionally, bulk RNA-seq reveals that in vivo glioma models treated with Delta-24-RGDOX exhibit activation of the AhR pathway network. This unexpected and paradoxical activation may be responsible for immune suppression mechanisms, which might hinder the effect of Delta-24-RGDOX. Based on these data, we combined two innovative strategies, the oncolytic virus Delta-24-RGDOX and AhR inhibitors. Survival analysis in immunocompetent models of gliomas treated with this combined therapy showed the greatest therapeutic benefit compared to monotherapy controls. These findings highlight the critical role of AhR activation triggered by Delta-24-RGDOX and position AhR as a potential therapeutic target for enhancing the efficacy of oncolytic adenovirus therapy in GBM.

Cytokines and Madness: A Unifying Hypothesis of Schizophrenia Involving Interleukin-22

Schizophrenia is a severe neuropsychiatric illness of uncertain etiopathogenesis in which antipsychotic drugs can attenuate the symptoms, but patients rarely return to the premorbid level of functioning. In fact, with each relapse, people living with schizophrenia progress toward disability and cognitive impairment. Moreover, our patients desire to live normal lives, to manage their daily affairs independently, date, get married, and raise and support a family. Those of us who work daily with schizophrenia patients know that these objectives are rarely met despite the novel and allegedly improved dopamine blockers. We hypothesize that poor outcomes in schizophrenia reflect the gray matter volume reduction, which continues despite antipsychotic treatment. We hypothesize further that increased gut barrier permeability, due to dysfunctional aryl hydrocarbon receptor (AhR), downregulates the gut barrier protectors, brain-derived neurotrophic factor (BDNF), and interleukin-22 (IL-22), facilitating microbial translocation into the systemic circulation, eventually reaching the brain. Recombinant human IL-22 could ameliorate the outcome of schizophrenia by limiting bacterial translocation and by initiating tissue repair. This short review examines the signal transducer and transcription-three (STAT3)/AhR axis and downregulation of IL-22 and BDNF with subsequent increase in gut barrier permeability. Based on the hypothesis presented here, we discuss alternative schizophrenia interventions, including AhR antagonists, mitochondrial transplant, membrane lipid replacement, and recombinant human IL-22.

Hydrogen isotope fractionation during aromatization to form alkylnaphthalene: Insights from pyrolysis experiments of 1-n-butyldecalin

Alkylnaphthalene homologues are important components of aromatic fraction in sedimentary organic matter and contain significantly geochemical information relative to formation and evolution of the host organic matter. They mainly originate from hydrocarbon aromatization reaction which involves the dehydrogenation of aliphatic rings resulting in the fractionation of stable hydrogen isotopes between aromatic hydrocarbons and their precursors. To examine these processes, this study thermally pyrolysed 1-n-butyldecalin (BD) at different time intervals under 360 °C/50 MPa to study the aromatization and hydrogen isotope fractionation during alkylnaphthalene formation and evolution. The relative content of aromatic products, such as naphthalene (N) and 1-methylnaphthalene (1-MN), increases with increasing aromatization. Sulfur enhanced the degree of aromatization during BD thermal evolution, resulting in greater N and 1-MN formation. For the compounds with the same carbon skeleton, i.e. tran-1-methyldecalin (1-MD), 5-methyltetraline (5-MT) and 1-MN, the 2H enrichment follows the order δ2H1-MD < δ2H5-MT < δ2H1-MN during the low thermal conversion of BD. However, the order was subsequently destroyed with increasing aromatization. The results indicate that hydrocarbon aromatization can enrich aromatic hydrocarbon in 2H, resulting in a higher δ2H value of higher aromatic-ring-number hydrocarbon than that of a lower aromatic-ring-number at low aromatization. However, 2H enrichment will decrease and even result in a reverse order with enhanced aromatization. Our findings are beneficial for understanding genetic mechanism and hydrogen isotope fractionation effect during the formation and evolution of aromatic hydrocarbons.

Crude Oil Biodegradation by a Biosurfactant-Producing Bacterial Consortium in High-Salinity Soil

Bioremediation is a promising strategy to remove crude oil contaminants. However, limited studies explored the potential of bacterial consortia on crude oil biodegradation in high salinity soil. In this study, four halotolerant strains (Pseudoxanthomonas sp. S1-2, Bacillus sp. S2-A, Dietzia sp. CN-3, and Acinetobacter sp. HC8-3S), with strong environmental tolerance (temperature, pH, and salinity), distinctive crude oil degradation, and beneficial biosurfactant production, were combined to construct a bacterial consortium. The inoculation of the consortium successfully degraded 97.1% of total petroleum hydrocarbons in 10 days, with notable removal of alkanes, cycloalkanes, branched alkanes, and aromatic hydrocarbons. Functional optimization showed that this consortium degraded crude oil effectively in a broad range of temperature (20–37 °C), pH (6–9), and salinity (0–100 g/L). In salt-enriched crude-oil-contaminated soil microcosms, the simultaneous treatment of bioaugmentation and biostimulation achieved the highest crude oil degradation rate of 568.6 mg/kg/d, compared to treatments involving abiotic factors, natural attenuation, biostimulation, and bioaugmentation after 60 days. Real-time PCR targeting the 16S rRNA and alkB genes showed the good adaptability and stability of this consortium. The degradation property of the constructed bacterial consortium and the engineered consortium strategy may have potential use in the bioremediation of crude oil pollution in high-salinity soil.

Production of Aviation Fuel-Range Hydrocarbons Through Catalytic Co-Pyrolysis of Polystyrene and Southern Pine

Sustainable aviation fuels (SAFs), produced from waste and renewable sources, are a promising means for reducing net greenhouse gas emissions from air travel while still maintaining the quality of air transportation expected. In this work, the catalytic co-pyrolysis of polystyrene and pine with red mud (bauxite residue) and ZSM-5 catalysts at temperatures of 450 °C, 500 °C, and 550 °C was investigated as a method for producing aromatic hydrocarbons with carbon numbers ranging from 7 to 17 for use as additives to blend with SAF produced through other methods to add the required quantity of aromatic molecules to these blends. The maximum yield of kerosene-range aromatic hydrocarbons was 620 mg per gram of feedstock (62% of feedstock was converted to kerosene-range hydrocarbons) obtained at 550 °C in the presence of ZSM-5. Additionally, it was noted that a positive synergy exists between pine and polystyrene feedstocks during co-pyrolysis that cracks solid and liquid products into gaseous products similarly to that of a catalyst. The co-pyrolysis of pine and polystyrene without a catalyst produced on average 17% or 36.3 mg more kerosene-range hydrocarbons than predicted, with a maximum yield of 266 mg of C7–C17 aromatic hydrocarbons per gram of feedstock (26.6% conversion of initial feedstock) obtained at 550 °C.

Highly Selective On‐Surface Dehydrogenative Aromatization of n‐Hexyl to Phenyl Substituents

Dehydrogenative aromatization of alkyl substituents represents a powerful approach to aryl‐substituted functional molecules. However, the inertness of alkyl groups and the need for harsh reaction conditions accompanied by low product selectivity hamper its widespread applications. Here, we demonstrate the highly selective on‐surface thermal aromatization of n‐hexyl substituents on polycyclic aromatic hydrocarbons (PAHs) to their phenyl‐substituted analogues under mild conditions. After depositing two representative precursor molecules, n‐hexyl‐substituted hexaphenylbenzene (HPB‐Hex) and bianthryl octacarboxylic tetraimide (BATI‐Hex), onto a pre‐heated Au(111) substrate, dehydroaromatization of the peripheral n‐hexyl groups into phenyl rings occurs, following the planarization of hexaphenylbenzene and bianthryl core. This process involves sequential intramolecular C‐C bond rotations, dehydrogenation, and cyclodehydrogenation reactions, yielding phenyl‐substituted hexabenzocoronene (HBC‐Ph) and bisanthene octacarboxylic tetraimides (BSTI‐Ph). The reaction sequences were monitored using scanning tunneling microscopy (STM) and bond‐resolved non‐contact atomic force microscopy (nc‐AFM), offering structural proof of both intermediates and final products. These experimental techniques were complemented by density functional theory (DFT) simulations, which facilitated the detection of crucial steps in the conversion of n‐hexyl to phenyl groups. Moreover, the effect of alkyl aromatization on the electronic properties of the newly formed aromatic hydrocarbons was elucidated using scanning tunneling spectroscopy (STS).

Highly Selective On‐Surface Dehydrogenative Aromatization of n‐Hexyl to Phenyl Substituents

Dehydrogenative aromatization of alkyl substituents represents a powerful approach to aryl‐substituted functional molecules. However, the inertness of alkyl groups and the need for harsh reaction conditions accompanied by low product selectivity hamper its widespread applications. Here, we demonstrate the highly selective on‐surface thermal aromatization of n‐hexyl substituents on polycyclic aromatic hydrocarbons (PAHs) to their phenyl‐substituted analogues under mild conditions. After depositing two representative precursor molecules, n‐hexyl‐substituted hexaphenylbenzene (HPB‐Hex) and bianthryl octacarboxylic tetraimide (BATI‐Hex), onto a pre‐heated Au(111) substrate, dehydroaromatization of the peripheral n‐hexyl groups into phenyl rings occurs, following the planarization of hexaphenylbenzene and bianthryl core. This process involves sequential intramolecular C‐C bond rotations, dehydrogenation, and cyclodehydrogenation reactions, yielding phenyl‐substituted hexabenzocoronene (HBC‐Ph) and bisanthene octacarboxylic tetraimides (BSTI‐Ph). The reaction sequences were monitored using scanning tunneling microscopy (STM) and bond‐resolved non‐contact atomic force microscopy (nc‐AFM), offering structural proof of both intermediates and final products. These experimental techniques were complemented by density functional theory (DFT) simulations, which facilitated the detection of crucial steps in the conversion of n‐hexyl to phenyl groups. Moreover, the effect of alkyl aromatization on the electronic properties of the newly formed aromatic hydrocarbons was elucidated using scanning tunneling spectroscopy (STS).

Recent Findings on the Pollution Levels in the Romanian Black Sea Ecosystem: Implications for Achieving Good Environmental Status (GES) Under the Marine Strategy Framework Directive (Directive 2008/56/EC)

This study provides a comprehensive evaluation of contamination levels in the Romanian Black Sea within the framework of the Marine Strategy Framework Directive (MSFD). Over the course of five oceanographic expeditions between 2020 and 2022, data were gathered from 70 stations in transitional, coastal, shelf, and offshore waters of the Black Sea. Analyses were conducted on water, sediment, and biota samples for key contaminants: heavy metals (HMs), polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs) such as organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs). The assessment identified contamination hotspots near riverine inputs, urban runoff, harbor activities, and industrial discharges. Offshore waters also showed measurable pollutant levels, likely from diffuse sources and atmospheric deposition. The key findings reveal the widespread contamination of HMs, PAHs, and POPs across the Romanian Black Sea, with concentrations in certain areas exceeding acceptable environmental thresholds, highlighting ongoing challenges for regional pollution management. PAHs were prevalent in both nearshore and offshore regions, while OCPs and PCBs were detected across various matrices, with significant concentrations observed in water and biota samples. The study emphasizes the importance of integrated assessments within the MSFD framework, suggesting that future evaluations should complement the “one out-all out” (OOAO) approach with multi-metric tools, to enhance the robustness of pollution status reporting. Despite improvements in some areas, contamination remains a critical challenge, requiring strengthened regulations, improved waste management, and increased regional cooperation to mitigate the ongoing risks to marine ecosystems. The findings provide valuable data for the upcoming national MSFD assessment cycle (2018–2023) and highlight the need for sustained monitoring and coordinated efforts to ensure long-term marine sustainability.

Study on Microstructure Evolution Characteristics of Coal in Low Temperature Oxidation Stage in Goaf of Longfeng Coal Mine

ABSTRACT Low temperature oxidation of coal is the nature of oxidation of coal with oxygen molecules at temperatures below its oxidation critical point or ignition point, usually from ambient temperature to about 200°C. Air leakage and uneven oxygen distribution significantly impact coal spontaneous combustion in goaf. Understanding the changes in free radicals and functional groups during low-temperature oxidation of coal under different oxygen concentrations is crucial for preventing and controlling residual coal self-ignition. This study employs Fourier transform infrared spectroscopy to analyze the effects of varying oxygen concentrations (3%, 5%, 9%, 15%, 21%) on functional groups and structural parameters during coal’s low-temperature oxidation. Results indicate that increasing oxygen concentration promotes the consumption of oxygen-containing functional groups, reducing their content from 71.9% to 52%. Concurrently, the activity and content of aromatic hydrocarbon functional groups rise rapidly from 4.8% to 52.6%. The aliphatic hydrocarbon structure shows a downward trend, indicating its minimal presence. Aromatic ring condensation increases coal sample aromaticity, suggesting higher maturity and weaker hydrocarbon generation potential, with minimal effect from oxygen concentration. Early-stage reactions show little change in coal’s basic structure, and coal-oxygen reactions remain low in low oxygen environments. This study provides an important basis for understanding the mechanism of coal spontaneous combustion in goaf and formulating effective prevention measures for coal spontaneous combustion.

The Impact of Feed Management Technologies on Mineral Oil Hydrocarbons (MOH) Contamination: A Comparative Farm Level Approach

Legislative frameworks about contamination are often limited to foods and underestimate the role of animal nutrition for safe production. This study aims to assess mineral oil hydrocarbon (MOH) contamination in feed and identify the technological factors that are contributing to this issue, particularly focused on mechanised harvesting and processing. Three dairy farms, classified by contamination risk (low, medium, and high), were selected, and fifteen feed samples were analysed using the coupled liquid chromatography–gas chromatography–flame ionisation detection (LC–GC–FID) method, with a microwave-assisted saponification (MAS) step to determine mineral oil saturated (MOSH) and aromatic (MOAH) hydrocarbon levels. Important contamination levels were observed depending on the technological development of each farm. MOSH levels ranged from 11.4 mg/kg to 81.40 mg/kg, while MOAH levels ranged from 0.5 mg/kg to 4.6 mg/kg. MOAH accounted for 4.74% of the total MOH content. The results showed a connection between feed production technologies and MOH contamination levels. Factors such as the mechanisation, the machinery used, and the storage conditions were potentially contributors to contamination, while chemical treatments had no direct impact but some potential risks. The contamination levels varied across farms, indicating certain contamination sources beyond technological factors. Advanced technological measures and proper equipment maintenance are suggested to mitigate MOH contamination risks in feed.

Sorption Properties of Bentonite-Based Organoclays with Amphoteric and Nonionic Surfactants in Relation to Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a major scientific challenge due to their profound impact on public and environmental health. Therefore, studying ways to detoxify PAHs is important. In this research, the adsorption ability of bentonite modified with five surfactants, including amphoteric (cocoamphodiacetate disodium and sodium cocoiminodipropionate) and nonionic (lauramine oxide, cocamide diethanolamine, and alkylpolyglucoside) substances for the adsorption of high-molecular benzo(a)pyrene and low-molecular naphthalene from the PAH group was studied. The bentonite and bentonite-based organoclays were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The results showed that the maximum adsorption of benzo(a)pyrene by organoclays increased compared with the initial mineral. The adsorption of benzo(a)pyrene is higher than that of naphthalene. The adsorption process of benzo(a)pyrene by bentonite and organoclays is predominantly monolayer, as it is better described by the Langmuir model (R2 0.77–0.98), while naphthalene is predominantly multilayer, described by the Freundlich model (R2 0.86–0.96). According to the effectiveness of sorption capacities of organoclays—including the degree of sorption, Langmuir and Freundlich constants, the value of maximum adsorption, Gibbs free energy, and the index of favorability of the adsorption process—the most effective modification was found. For the adsorption of benzo(a)pyrene the best was cocoamphodiacetate disodium, and for naphthalene it was sodium cocoiminodipropionate.