Total Sulfur Content Research Articles

Influences of ternary ethanol methanol gasoline mixtures on the performance of a spark ignition engine

The principal aim of this study is to determine the influence of ternary mixtures of gasoline, ethanol and methanol as fuels, on a spark ignition engine performance. Four samples of fuels were prepared with varying concentrations of each constituent. The different fuels studied are: EM0 (gasoline), EM5 (2.5% ethanol, 2.5% methanol, 95% gasoline), EM10 (5% ethanol, 5% methanol, 90% gasoline) and EM15 (7.5% ethanol, 7.5% methanol, 85% gasoline). A battery of tests (appearance, color, odor, lower heating value, density, research octane number, vapor pressure, total sulfur content and distillation curve) was carried out on these mixtures in order to determine their physicochemical properties and their ability to be used as fuel. Then, the different prepared mixtures were used as fuels to determine the performance of the 4-stroke, carbureted Renault 4 engine. These tests show that these additions give rise to a fuel with a lower sulfur level, a higher RON and a lower low heating value compared to unleaded gasoline and therefore improve, depending on the circumstances, the power of the fuel engine, its specific consumption, its speed and combustion. At the end of this study, it was concluded that the use of fuel mixtures was relevant for high speeds and also more suitable for total loads.

Diversity and Distribution of Methane Functional Microorganisms in Sedimentary Columns of Hongfeng Reservoir in Different Seasons.

Freshwater ecosystem is a significant natural source of CH4 emission in the atmosphere. To fully understand the dynamics of methane emissions in reservoirs, it is essential to grasp the temporal and vertical distribution patterns, as well as the factors that influence the methanogenic bacterial communities within the sediments. This study investigates the methane dynamics, carbon isotope fractionation (δ13CH4), and abundance of functional microorganisms along the geochemical gradient in the in situ sedimentary column of Hongfeng Reservoir (China). Notably, the methane concentration in sediment in summer ranged in 15.39-127.22µmol/L, which is twice as high as wintertime concentrations in the surface layer near the sediment-water interface (0-10cm depth). Illumina sequencing of the sediments identified 11 genera affiliated with methanogenic archaea, with dominant genus Methanosaeta reaching a relative abundance of 34.95% in summer. The total carbon (TOC) content in sedimentary columns in different seasons is positively correlated with Methanosarcina (P < 0.05). In addition, seasonal discrepancies are observed in the sediment profiles for total nitrogen (TN), sulfate (SO42-), and ferrous iron (Fe2+) concentrations. The concentration of total nitrogen (TN) is higher in summer than in winter. In summer, sulfate accumulates in the middle layer of the sedimentary column, while in winter, the maximum concentration of sulfate in the surface layer reaches 0.65mmol/L. These geochemical gradients drive the biological transformation of nitrogen, sulfur, and iron, may also be linked to the consumption of methane. Thus, it is established that the temporal and spatial dynamics of methanogenic communities in sediments significantly influence the fluctuations in methane release fluxes within reservoirs, highlighting the necessity to account for seasonal biological variations when assessing greenhouse gas emissions from reservoirs.

Desulfurization of oil from Kizelov deposits under the effect of metallic sodium nanoparticles

Despite the persistent increase in demand for energy resources, the world maintains abundant reserves of heavy oils, underscoring the continued relevance of research aimed at enhancing their extraction efficiency. This study explores laboratory simulations of aquathermolysis processes and investigates the transformation of oil-containing rock from the Kizelov deposit, both with and without the presence of a sodium nanosuspension, within a water vapor environment at temperatures ranging from 150 to 300 °C. Employing various analytical methods, including determination of gas composition, X-ray fluorescence spectroscopy, SARA analysis, gas chromatography-mass spectrometry, and X-ray diffraction analysis, the research unveils significant insights. Notably, thermal steam treatment (TST) augmented with a sodium suspension proves effective in reducing total sulfur content by 86–95% even at lower temperatures. Moreover, TST at 200 °C, coupled with the introduction of metallic sodium, markedly enhances the concentration of saturated hydrocarbons in the oil by threefold. The addition of a sodium nanosuspension during the hydrothermal treatment of oil-containing rock yields intriguing outcomes in the aromatic fraction of extracts, resulting in the formation of novel compounds, such as alkyl diphenyls, alkyl phenylnaphthalenes, and piperidines, while facilitating the complete elimination of sulfur-containing aromatic compounds. Additionally, the impact of sodium on the mineralogical composition of the rock is elucidated, particularly in the formation of minerals such as portlandite, shortite, and nierereite.

Removal of Sulfur Content in Groundwater Using Marble Filter in a Cascade Design

Alluvial aquifer are one of Malaysia’s most abundant groundwater resources, highly demanded in East Coast area. However, the presence of sulfur in these aquifers causes the emission of hydrogen sulfide gas. This research aimed to provide an alternative study for removing sulfur using marble filter media in a cascade column design, where water flows from the highest to the lowest column. Two groups of marble sizes were involved in this filter: pebbles and sand-sized particles. The treatment used raw groundwater with the highest concentration of total sulfur being 537.1 ppm. Sand-sized marble had the highest efficiency of sulfur removal, reaching 98.3% at a flow rate of 0.011 l/s. As a result of the effective filtration, the true color reached 33-34 pt/Co, significantly reduced from the source value of 1000-1012 pt/Co. The application of marble for treating groundwater with the sulfur issue is still novel and promising for groundwater filtration, potentially benefiting consumers facing this problem.

The development and application of a new method for quantifying total atmospheric sulfur in the Alberta Oil Sands

ABSTRACT Continuous ambient sulfur measurements are routinely conducted around the globe at numerous monitoring sites impacted by industrial sources such as gas and oil processing facilities, pulp and paper mills, smelters, sewage treatment facilities, or concentrated animal feeding operations, as well as natural sources such as volcanoes. Various jurisdictions have or plan to establish Air Ambient Quality Objectives/Guidelines/Standards for Total Reduced Sulfur (TRS) based on odor perception and/or health effects. A conventional TRS monitoring technique is widely used, but few studies have looked at potential biases in the resulting TRS measurements. This paper presents a novel method to quantify Total Sulfur (TS) concentrations to investigate odor events caused by sulfur compounds, and to construct the sulfur budget for sulfur dioxide, particle sulfate, hydrogen sulfide (H2S) and the sum of all remaining reduced sulfur compounds (non-H2S RSCs). This methodology was tested and improved through multi-year monitoring (2013-2017) at the Oski-ôtin site in the indigenous community of Fort McKay, in the Alberta Oil Sands Region (AOSR). Comparisons with SO2 and conventional TRS data from two long-term monitoring sites located within five kilometers of Oski-ôtin suggest that the conventional approach for TRS is biased low by 20% on average. Based on this new method, Sulfur dioxide (SO2) was observed to be responsible for about 40% of the TS mass in Fort McKay, while TRS and particulate sulfate made up 50% and 10%, respectively. TRS dominated the distribution during winter months when SO2 plumes emitted from stacks tended to remain elevated due to diminished vertical mixing. During periods with TS below 5 ppb, which was 84% of the time, TRS (with H2S) accounted for 55% of the sulfur mass observed in Fort McKay.

Mineral nutrition for Cannabis sativa in the vegetative stage using response surface analysis.

Cannabis cultivated for medical and adult use is a high-value horticultural crop in North America; however, we lack information on its optimal mineral nutrition due to previous legal restrictions. This study evaluated the mineral requirements of nitrogen (N), phosphorus (P), and potassium (K) for cannabis in the vegetative stage using response surface analysis. Plants were cultivated in a hydroponic system with various nutrient solution treatments (mg L-1) of N (132.7, 160, 200, 240, and 267.3), P (9.6, 30, 60, 90, and 110.5), and K (20.8, 60, 117.5, 175, and 214.2) according to a central composite design. Nutrient interactions (N × K, K × P, and N × P × K) had a significant effect on the vegetative growth of the cannabis plants. N × K interaction had a significant effect on leaf mass and stem mass. K × P interaction had a significant effect on dry root mass, leaf mass, stem mass, leaf area, specific leaf area, and chlorophyll a and b contents. N × P × K interaction had a significant effect on root mass, leaf mass, stem mass, stem diameter, leaf area, and chlorophyll a and b contents. The optimum concentrations of total nitrogen, P, K, calcium, and sulfur in the cannabis leaves were 0.54, 0.073, 0.27, 0.56, and 0.38 mg g-1, respectively. An increase in P and K concentrations decreased the magnesium concentration in the leaves, but it was unaffected by the increase in N concentration. The recommended primary macronutrients for cannabis plants in the vegetative stage based on the maximum desirability and nutrient use efficiencies were 160-200 mg L-1 N, 30 mg L-1 P, and 60 mg L-1 K. These findings can offer valuable insight and guidance to growers regarding the mineral requirements for cannabis during the vegetative stage.

Enhancing Electrolyte Stability and Performance in Vanadium Redox Flow Batteries through Inorganic Additives Investigation

The electrolyte is a crucial component of the vanadium redox flow battery (VRFB), exerting a substantial influence on cell properties, performance, and cost. Its composition significantly impacts energy density, operational temperature range, and practical applications of the VRFB. Various strategies have been proposed to enhance energy density and broaden the temperature range.[1] For instance, the presence of electrolyte impurities or the addition of specific chemical compounds into the vanadium solution can modify electrolyte stability, affecting cell performance, temperature range, energy density, electrochemical kinetics, and cost-effectiveness. The practical composition of vanadium battery electrolytes typically maintains vanadium concentrations between 1.6 and 2 M within a total sulfate concentration of 4−5 M, with operational temperatures ranging between 10 and 40 °C.[2] At these levels, electrolyte operation typically remains in a supersaturated or supercritical state. Consequently, the research and development of additives have emerged as a focal point within electrolyte studies, aimed at sustaining stable operation with high-concentration electrolytes at a broader temperature range.The current work involves a thorough investigation of various inorganic additives in vanadium electrolytes tailored for VRFBs, conducted across a range of temperatures and sulfuric acid concentrations. Specifically, the study targets distinct oxidation states of vanadium ions, including V(II), V(III), V(IV), and V(V), individually examined under different temperature and acid concentration conditions. This is because the dissolution behavior of V(V) ions can be enhanced by increasing sulfuric acid concentration or reducing the temperature, whereas V(IV), V(III), and V(II) ions can be stabilized by elevating temperature and decreasing sulfuric acid concentration. Additionally, the performance of these additives is evaluated in flow cells to gauge their effectiveness within the battery system, providing valuable insights into their real-world performance and potential for enhancing VRFB efficiency and reliability.The expense associated with electrolyte production poses a significant barrier to the widespread deployment of vanadium redox flow batteries (VRFBs).[3] Even minor enhancements in electrolyte purity beyond the threshold of 98.5% can substantially inflate electrolyte costs. However, the presence of impurities within the electrolyte solution can trigger unwanted phenomena such as precipitation formation and hydrogen evolution, undermining battery performance and reliability. In response to this challenge, the research endeavors to identify additives capable of mitigating the adverse effects of impurities and sustaining optimal flow battery operation. The investigation has focused on the utilization of lead nitrate as an additive, revealing promising outcomes. Specifically, lead nitrate demonstrates the ability to suppress hydrogen evolution induced by select metal ions commonly found as impurities in electrolyte solutions. Furthermore, the experiments have shown that lead nitrate can enhance battery performance, particularly in scenarios where the concentration of metal ions is increased. These findings highlight the potential of lead nitrate as a viable additive for improving the operational efficiency and longevity of VRFBs, paving the way for more cost-effective and reliable energy storage solutions.In conclusion, the research underscores the critical role of electrolyte composition in VRFBs. Thorough investigation of various inorganic additives and their impact on electrolyte stability and battery performance aims to address key challenges such as impurity-induced precipitation formation and hydrogen evolution. Additionally, it aims to improve electrolyte stability across a broader operating temperature range, particularly with high-concentration electrolytes. The findings highlight the potential of additives to enhance VRFB efficiency and reliability, offering promising avenues for the development of more cost-effective and reliable energy storage solutions. Through continued research and development in this field, significant advancements in VRFB technology is envisioned, facilitating its broader adoption and integration into various energy storage applications.

Effects of climate change and methane-rich fluid activity on sedimentary sulfur geochemical records in the northern South China Sea since mid-Pleistocene

Microbial sulfate reduction (MSR) and associated pyritic sulfide formation are important diagenetic processes in marine sediments. The sulfur isotopic composition of pyrite (δ34Spyr) is proven to be sensitive to changes in sedimentation rates and the content and reactivity of organic carbon, especially on the continental shelves and upper slopes (water depth < 350 m). However, the diagenetic responses of sulfur to variations in climatic and depositional conditions in the deep-sea sediments are still poorly understood. This study combines element contents and isotopes to characterize diagenetic interplays of sulfur, organic carbon, and methane in the continental slope sediments of the northern South China Sea since the mid-Pleistocene. Our data suggest that the total organic carbon (TOC) increased during glacial times, implying enhanced primary productivity due to increased nutrient supply by the East Asian Winter Monsoon, in addition to efficient transfer of organic carbon and better preservation of organic carbon due to reduced bottom water oxygen. Total sulfur and chromium reduction sulfur contents varied concomitantly with the TOC, suggesting an increased burial of organic carbon that enhanced the organoclastic sulfate reduction (OSR) and the formation of authigenic pyrite. The environmental changes did not induce a significant shift in δ34Spyr, due most likely to relatively low sedimentation rates and large fractionation in sulfur isotope through OSR during the glacial-interglacial cycles. Instead, it is hypothesized that the sulfate-driven anaerobic methane oxidation promoted the formation of a higher amount of authigenic pyrite. Consequently, it created a closed diagenetic system leading to positive excursions in δ34Spyr at the sulfate-methane transition zone. Our results suggest the vulnerability of pyrite formation and its sulfur isotopic composition to the changes in monsoon-driven primary productivity and the methane-rich fluid migrations in the continental margin sediments. This study complements the growing evidence for the local diagenetic controls on sedimentary sulfur geochemical records by highlighting the importance of early diagenesis in paleoenvironment reconstruction based on the content and sulfur isotopic composition of pyrite.

Molecular compositional variation of organic matter deposited on the East Tasman Plateau during the Paleocene–Eocene Thermal Maximum

Molecular compositions in sediments collected by Ocean Drilling Program Leg 189 at Site 1172 in the Tasmanian Gateway, Australia have been characterised by gas chromatography–mass spectrometry to assess the impact of the Paleocene–Eocene Thermal Maximum (PETM) on organic matter origins and evolution. Total organic carbon (TOC) and sulfur contents reach the lowest values immediately before the initiation of the negative carbon isotope excursion (CIE) in the shallow marine environment on the East Tasman Plateau. The TOC content increases slightly while the sulfur content increases more substantially during deposition of the CIE, suggesting the occurrence of low-oxygen environments during the PETM event. The studied section is thermally immature, as shown by the dominance of biological configuration biomarkers such as 17β(H),21β(H)-hopanes (ββ) and hopenes. Changes in relative abundance of compound classes and isomer ratios are largely caused by the variation of source inputs and depositional conditions. Very low abundance of marine steroids during the CIE, but very enriched hopanoids, indicate low marine productivity, in accord with substantial remineralisation of organic matter in the bottom waters. The ββ-hopanes are the most abundant hopanoid series, followed by the neohop-13(18)-ene and hop-17(21)-ene series, further verifying the immaturity of the organic constituents in the samples. Hopane ratios (ββ/(βα + αβ) and βα/(βα + αβ) with different carbon numbers are systematically higher in sediments deposited during the CIE than those formed pre- and post-CIE, suggest increased bacterial inputs. Higher C30/C29 and C30/C31 hopanoid ratios in the CIE sediments are consistent with a greater contribution from in situ bacterial organic matter, rather than continental soil erosion by flooding. This is supported by the higher C27–32 hopanoids/(C27 + C29 + C31n-alkanes) ratio and sulfur content during the CIE. A relatively lower TOC content in the sediments formed during the PETM is inferred to have been caused by dilution by both enhanced detrital input and intensified bacterial consumption. This study demonstrates that the biomarker approach can play an important role in the identification of organic matter origin and characterisation of depositional environment for PETM sequences.

Organic petrology and geochemistry of the late Neogene Shizigou Formation in the Qaidam Basin, China: Characteristics of a prospective microbial gas source rock

The discovery of natural gas trapped in the late Neogene Shizigou Formation in the Yikeyawuru anticline indicates the potential for additional microbial gas reservoirs outside of the primary exploration targets for microbial gas in the younger, i.e., the Pleistocene sediments of the Qaidam Basin. In this study, a detailed investigation is presented on the bulk geochemistry and organic petrography of the potential microbial source rocks as well as on molecular organic geochemistry of the solvent extracts obtained from the late Neogene Shizigou Formation of the Yiliping Depression. The objectives are to elucidate i) the depositional environment, ii) biological sources of organic matter (OM), and iii) biodegradation levels in these microbial gas source rocks.The samples from the well situated at the center of the Yiliping Depression (the H 1 well) exhibit minor variations in total organic carbon (TOC) and total sulfur contents, whereas the samples from the well located at the margin of the depression (the Y 3 well) show large variations in these values. All these samples are presently thermally immature. The kerogen of the TOC-rich Y 3 well samples is mainly composed of mixed types II–III kerogen and characterized by a complex maceral composition (i.e., a mixture of large fragments of huminite, semifusinite, fusinite, resinite/fluorinite, lamalginite, and liptodetrinite). In contrast, samples from the H 1 well contain typically type III kerogen with a less complex maceral composition consisting of huminite, lamalginite, and liptodetrinite. The molecular data illustrates that the OM is predominantly derived from bacterial and algal biomass as well as aquatic higher plants (primarily in the Y 3 well samples), while angiosperms are the primary source of the subordinate terrestrial OM in the samples. The marginal area is characterized by salinity levels akin to normal marine conditions with bottom-water paleoredox conditions ranging from dyoxic (samples with high TOC content) to oxic, whereas the central area developed a mesosaline environment with oxic bottom-water conditions prevailing. In contrast to the primary microbial gas producing layer, the Pleistocene Qigequan Formation, the late Neogene Shizigou Formation exhibits a higher contribution of emergent macrophytes but a reduced abundance of lower aquatic organisms in the OM as well as a higher salinity level in the water column. Despite the late Neogene Shizigou Formation demonstrating a lower potential for hydrocarbon generation and a lower degree of biodegradation of OM than the Qigequan Formation, it still shows generally favorable geological and geochemical conditions that are conducive to the development of microbial gas reservoirs, which is underscored by the biodegradation levels between 3 and 4 for the studied samples.

Understanding the ecological versatility of Tetracladium species in temperate forest soils.

Although Tetracladium species have traditionally been studied as aquatic saprotrophs, the growing number of metagenomic and metabarcoding reports detecting them in soil environments raises important questions about their ecological adaptability and versatility. We investigated the factors associated with the relative abundance, diversity and ecological dynamics of Tetracladium in temperate forest soils. Through amplicon sequencing of soil samples collected from 54 stands in six forest sites across the eastern United States, we identified 29 distinct Amplicon Sequence Variants (ASVs) representing Tetracladium, with large differences in relative abundance and small changes in ASV community composition among sites. Tetracladium richness was positively related to soil pH, soil temperature, total sulphur and silt content, and negatively related to plant litter quality, such as the lignin-to-nitrogen ratio and the lignocellulose index. Co-occurrence network analysis indicated negative relationships between Tetracladium and other abundant fungal groups, including ectomycorrhizal and arbuscular mycorrhizal fungi. Collectively, our findings highlight the ecological significance of Tetracladium in temperate forest soils and emphasize the importance of site-specific factors and microbial interactions in shaping their distribution patterns and ecological dynamics.

Fiber morphological characteristics of bamboo Ferrocalamus strictus culms from different geographical distribution regions

The fiber index including fiber length, width, wall thickness and lumen diameter of Ferrocalamus strictus culms (1, 2, and ≥ 3 years) from Jinping, Mojiang and Lvchun counties of Yunnan Province was determined and the elemental content of the soil was also determined to analyze the fiber characteristics. The average relative fiber index measured for F. strictus culms were fiber length (1.30 mm), width (21.57 μm), slenderness ratio (60.79 μm), wall thickness (4.21 μm), lumen diameter (7.22 μm), and runkel ratio (1.22 μm), which belonged to the range of middle and long fibers. The fiber length increased with the culm age. The proportion of long fiber increased while short fibers decreased along with culm maturing. The fiber morphology did not show a specific trend with the culm height. Fiber length reached the maximum in the bottom portions of the culms. There is a correlation between fiber morphology and soil elements, the content of organic matter, total potassium, total sulfur, total aluminum, total zinc, total iron, total boron, alkali-hydrolyzed nitrogen and available silicon in the soil affects fiber morphology. The content of organic matter, total boron and alkali-hydrolyzed nitrogen in the soil from Mojiang County was largest. Comparatively, the culm fiber in Mojiang County had the best fiber index performance for utilization, since the greatest proportion of medium and long fibers and the optimal distribution of fiber length frequency was obtained from the culms in Mojiang County. This study can provide a theoretical basis for large-scale bamboo forest cultivation and the development and utilization of bamboo culm fiber.

BIOLOGICALLY ACTIVE SUBSTANCES OF WILD PLANTS MEDICINAL PLANT Salicornia europaea L., NATIVE TO THE ABAI REGION

The article presents the results of a study of the nominal part of the Salicornia europaea L. population growing in the Republic of Abai. An elemental analysis of plant raw materials was carried out, the content of total carbon, organic carbon, nitrogen and sulfur was determined. An alcoholic extract of vegetable raw materials was obtained in the Soxlet apparatus. The extract was filtered and used for chemical analysis. Qualitative reactions revealed the presence of a number of biologically active substances in the extract, such as proteins, terpenes and steroids, tannins, xanthones, phenolic compounds, flavonoids, carboxylic acids and caratinoids. The quantitative determination of flavonoids and catechins in the extract was carried out. The spectrophotometry method showed that the content of flavonoids in the plant extract in terms of quercetin is 0.31±0.03 µg/ml. The content of catechins in the extract was determined by liquid chromatography, which amounted to 34.01±3.40 µg/ml. The FRAP (Iron Reducing Antioxidant Power) method is used an antioxidant strategy. It has been shown that with an increase in the concentration of the extract from 0.01 to 0.05 mg/ml, the antioxidant activity increases. At an extract concentration of 0.05 mg/ml, the antioxidant activity is 3.084 mg AAE/ml of the extract. It is concluded that the plant can serve as a raw material for production of cosmeceutical products.

Exploration geochemical evidence for the genesis of the Jiaodong gold deposits in eastern China: A case study of the Haiyu gold deposit

Jiaodong is the largest gold province in China and has great potential for further prospecting. It has been confirmed that the enrichment of Au is always accompanied by pyritization in Jiaodong gold deposits, so the genesis of pyritization in gold deposits and the mechanism of Au enrichment associated with pyritization has always been an issue of discussion to the researchers, the relationship between pyritization and Au enrichment is still unclear. In order to solve this problem, this paper studied the occurrence state and transformation characteristics of S in the ore-bearing geological bodies and discussed the mechanism of Au enrichment. 84 samples were collected from the drill hole ZK3006 of the Haiyu gold deposit, the average sampling interval was 15m, and 7 specific elements/analytical indexes were measured (Total sulfur, Reduced sulfur, Na2O,CaO, Sr, Ba, and Au), Burning-iodine quantity method was used to measure the content of Total sulfur, Combustion neutralization method was used to measure the content of Reduced sulfur Inductively coupled plasma-atomic emission spectrometry was used to measure the content of Na2O and CaO, Wavelength dispersive X-Ray fluorescence spectrometry was used to measure the content of Sr and Ba, and Foamed plastic enrichment-inductively coupled plasma-mass spectrometry was used to measure the content of Au.

Use of a Glaciogene Marine Clay (Ilulissat, Greenland) in a Pilot Production of Red Bricks.

Uplifted occurrences of fine-grained glaciogene marine sediments are found throughout the northern hemisphere. These sediments could be used to produce local construction materials, to rely less on imported construction materials from southern regions. In this study, a representative occurrence from Ilulissat, West Greenland, was investigated as a potential resource for local brick production. The study comprised three parts: (1) raw material characterization based on grain size distribution, major element chemistry, including total carbon, sulfur, and chloride concentrations, mineralogy, morphology, and Atterberg limits; (2) the production of test bricks at a Danish brickwork; and (3) testing of the bricks based on total shrinkage, water absorption, hygroscopic adsorption, open porosity, bulk density, compression strength, and mineralogy. The bricks produced proved to have excellent compression strength, low open porosity, and low water absorption. The shrinkage could be reduced by adding 10% chamotte to the marine sediment. Based on the investigated properties, this indicates that this type of clay is highly suitable as a resource for bricks.

Assessing hydrogen production potential from carbonate and shale source rocks: A geochemical investigation

The global push towards achieving net-zero carbon dioxide emissions by 2050 shows the urgency of transitioning to a hydrogen-based economy, with clean hydrogen fuel emerging as a fundamental component of future energy consumption. This study explores hydrogen production from geological sources, specifically organic-rich Shale and Carbonate mudrocks, as a significant and sustainable method for natural hydrogen production. Recognizing the critical challenge posed by the interaction of hydrogen with rock-forming minerals and organic matter during production, this research emphasizes the need for a comprehensive understanding of the geochemical composition of these rock materials. To assess the feasibility and implications of utilizing organic-rich source rocks for hydrogen production, we conducted thorough analyses of source rock samples from different formations. The representatives’ samples were subjected to comprehensive analyses including Rock-Eval pyrolysis, X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM) examinations, and gas chromatography (GC) analysis of the produced gas. Our results revealed that the high total organic carbon (TOC) samples (average 14.7 %) with Type I and II kerogens yielded substantial hydrogen-rich gases, approximately 44.71 % and 36.02 % for SH-O1 and JOS samples, respectively. JOS produced slightly higher hydrocarbon gases (∼50 %) compared to SH-O1 (∼45 %), along with more H2S (5.78 %), due to higher total sulfur content. In contrast, the SH-C1 sample, characterized by very low TOC (0.27 %), predominantly quartz and muscovite minerals (>78 %), and Type IV kerogen, produced higher CO2 (22.09 %) and minimal hydrogen (1.27 %), highlighting the influence of mineralogical and geochemical composition. This study suggests that hydrocarbon source rocks with high organic matter content hold significant potential for maximizing energy gas recovery (>85 %, including hydrogen and hydrocarbons) through the pyrolysis of their kerogen content. These findings demonstrate the viability of hydrogen gas production from unconventional sources such as organic-rich shales, potentially impacting strategies for sustainable energy production and contributing significantly to global decarbonization efforts.

Imminent prognosis for piperazinium-based ionic liquids applications for coal desulfurization

Sulfur is one of the most important quality parameters for coal rank and utility in power generation. Combustion of coal having high sulfur content leads to SOx emissions which have detrimental impacts on the environment and human health. For sulfur remediation, N-methyl piperazinium-based room temperature ionic liquids (RTILs) were synthesized with two acidic anions precursors’ dimethyl sulfate and Perchloric acid. These novel RTILs were characterized using standardized analytical techniques of FTIR, 1H NMR, 13C NMR, HPLC, and TGA/DSC. Thermal stability of dimethyl piperazinium methyl sulfate [DMPI+][MeSO4−] and methyl piperazinium perchlorate [MPI+][ClO4−] was 284 °C and 256 °C. The proximate and ultimate analysis of coal samples collected from block II of the Thar coal field shows high moisture content (29–47 %) and gross calorific value between 5006–6660 Btu/lb suggesting it is Lignite-B type fuel. Total sulfur content in coal samples was 1–4.1 % reflecting variable degree of sulfurization. Coal cleansing through oxidative extractive desulfurization theme using nifty combinations of these acidic RTILs was verified by HPLC, FTIR, CHNS Elemental Analyzer, and X-ray Florescence (XRF) techniques. Sulfur leaching from the coal matrix was higher for methyl piperazinium perchlorate and an 85 % decrease in the sulfur part of coal along with increased heat content through this study suggests cleaner and sustainable use of coal.

Significant correlations between heavy metals and prokaryotes in the Okinawa Trough hydrothermal sediments

Prokaryotes play crucial roles in hydrothermal vent ecosystems, yet their interactions with heavy metals are not well understood. This study explored the diversity of prokaryotic communities and their correlations with heavy metals and nutrient elements in hydrothermal sediments from Okinawa Trough. A total of 117 bacterial genera in 26 bacterial phyla and 10 archaeal classes in 3 archaeal phyla were identified, including dominant prokaryotic phyla Planctomycetes, Acidobacteria, Verrucomicrobia, and Euryarchaeota. Furthermore, Fe (39.61 mg/g), Mn (2.84 mg/g) and Ba (0.36 mg/g) were found to be the most abundant heavy metals in the Okinawa hydrothermal sediments. Notably, the concentrations of Zn, Ba, Mn, total organic carbon, and total nitrogen significantly increased, whereas the total sulfur concentration distinctively decreased at sampling sites farther from hydrothermal vents. These changes corresponded with reductions in prokaryotic abundance and diversity. Most heavy metals, including Mn, Fe, Co, Cu and As, presented significant positive correlations with a number of prokaryotic genera in the nearby sediment samples. In contrast, both positive and negative correlations with prokaryotes were observed in remote sediment. The keystone taxa include Magnetospirillum, GOUTA19, Lysobacter, Kaistobacter, Treponema, and Clostridium were detected through prokaryote interspecies interactions. The functional predictions revealed significant genes involved in carbon fixation, nitrogen/sulfur cycling, heat shock protein, and metal resistance pathways. Structural equation modeling confirmed that metal and nutrient elements directly influence the composition of prokaryotic communities, which in turn affects the relative abundance of functional genes.

How can the microbial community in watershed sediment maintain its resistance in the presence of shifting antibiotic residuals?

The widespread presence of antibiotics in global watershed environments poses a serious threat to public health and ecosystems. It is essential to examine the resistance of microbial communities in watershed environments in response to shifting antibiotic residues. Sediment samples were collected from seven sites across a watershed, encompassing surface sediment (0–10 cm) and bottom sediment (30–40 cm) depths. The aim was to replicate exposure scenarios to different antibiotics (oxytetracycline (OTC) and sulfadiazine (SD)) at varying concentrations (0, 10, and 100 μg/L) in sediment overlying water, within controlled laboratory settings. The study findings revealed significant variations in the microbial community structure of sediments between different treatments, with distinct differences observed in the upper stream and top sediment layers compared to the sediments located downstream and in the bottom layers. After the introduction of antibiotics, a significant decrease in microbial nodes was observed in the genus-level co-occurrence network analysis of the bottom sediment layer, particularly in the OTC treatment groups. In contrast, the downstream region displayed more robust correlations among the top 20 genera than the upstream area. There was no significant variance observed in the expression of Antibiotic resistance genes (ARGs), consisting of tetracycline resistance genes (tetC, tetG, tetM, tetW, and tetX) and sulfonamide resistance genes (sul1, sul2, and sul3), between sediments in the top and bottom layers. Nevertheless, downstream samples exhibited significantly higher levels of ARGs when compared to upstream samples. Network correlation analysis indicated notably lower correlations between ARGs and bacterial genera in sediments from upstream or surface layers compared to those in downstream or deeper layers. Moreover, correlations in the sediments from surface layers and upstream regions showed a decreasing trend with increasing SD exposure concentrations, while those in deeper layers and downstream areas remained relatively stable. The presence of antibiotics notably enhanced the correlation between sediment properties and ARGs, particularly emphasizing associations with total carbon, nitrogen, and sulfur content. However, the introduction of SD and OTC resulted in a decrease in the influence of these sediment factors on microbial community functions related to sulfur and nitrogen metabolism, as indicated by KEGG (Kyoto Encyclopedia of Genes and Genomes) annotation. The research provided empirical evidence on how microbial resistance responds to changes in antibiotics in sediment samples taken from various depths and locations within a watershed. It emphasized the urgent need for heightened awareness of the movement and alteration of antibiotic resistance patterns in watershed ecosystems.

Dominant host phase of mercury within the sediments of the East China Sea inner shelf: Implications for mercury inputs

Mercury (Hg) concentrations normalized to their dominant hosts have been widely used to identify geological events such as massive volcanic eruptions. However, the modern Hg cycle has significantly changed, and the implications of host-normalized Hg concentrations for the Hg dynamics in contemporary coastal environments (e.g., sources, delivery mechanisms, and Hg fluxes) remain poorly understood. In this study, 66 surface sediment samples from the continental shelf of the East China Sea (ECS) were analyzed, and the total organic carbon (TOC), aluminum (Al), total sulfur (TS), and Hg concentrations were determined. Our results support that organic matter predominantly hosts Hg in these sediments. Factors such as the Hg source and abundances of organic fractions influence Hg distributions, with notable enrichment in the Changjiang River estuary and the inner shelf of the ECS, especially near the mud depocenter located off the Oujiang River estuary. The oxic to suboxic redox state and the lack of significant sulfide accumulation in surface sediments suggest that sulfides are not the primary Hg hosts. The Hg/TOC ratios, ranging from 3.0 to 169.6 (ppb/%), are particularly high in the Changjiang River estuary and exhibit an exponential correlation with the Hg accumulation rates (Hg-AR). These findings suggest that the host-normalized Hg concentration could serve as a valuable tool for assessing Hg dynamics where the accumulation rates are uncertain.