Sulfate Minerals Research Articles

Investigating the impact of microplastics on sulfur mineralization in different soil types: A mechanism study

Microplastics can affect the physicochemical properties of soil and soil microorganisms, potentially resulting in changes in the soil sulfur mineralization and its capacity to supply available sulfur. However, the specific mechanisms underlying these effects remain unclear. We performed soil microcosm experiments, in which the effects of polystyrene (PS) and polyphenylene sulfide (PPS) microplastics on sulfur mineralization were examined in black, meadow, and paddy soils under flooded and dry conditions. Under dry condition, the presence of PS and PPS microplastics impeded sulfur (S) mineralization in black and paddy soils, but promoted sulfur mineralization in meadow soil. The size of microplastics was identified as the primary factor influencing sulfur mineralization in black soil, while in meadow soil, it was influenced by the microplastics type. In the case of paddy soil, the concentration of microplastics was the key factor affecting sulfur mineralization. During the flooding period, PS and PPS microplastics in black and paddy soils curtailed sulfur mineralization, however expedited sulfur mineralization in meadow soil, with PS enhancing soil sulfur mineralization more pronouncedly than PPS in black soil. The type and concentration of microplastics were identified as the main factors affecting sulfur mineralization in black soil, while in paddy soil, it was influenced by the size of microplastics. The principal regulating factors of soil sulfur mineralization were the sulphatase and arylsulfatase enzymes produced by Actinobacteria, Xanthomonadales, and Rhizobiales microorganisms, while organic matter and Olsen-P also had an influential role. Additionally, microplastics directly affected the structure of soil enzymes, thereby altering soil enzyme activities. This study provided insights into the mechanism by which microplastics affect soil sulfur mineralization, offering significant implications for assessing the influence of microplastics on soil sulfur availability and making informed decisions about sulfur application in future agricultural practices.

Influence of slurry acidification with H2SO4 on soil pH, N, P, S, and C dynamics: Incubation experiment

Acidifying slurry with sulfuric acid (H2SO4) is practiced in some countries for reducing ammonia (NH3) emissions during slurry storage and spreading to land. However, knowledge on how the application of acidified slurry affects soil health and nutrient cycling is lacking. This is particularly important since acidification with H2SO4 can substitute a sulfur (S) mineral fertilizer to increasingly S-deficient agricultural soils. We hypothesized that (ⅰ) slurry acidification would decrease the soil pH over a prolonged period, and as a result (ⅱ) would increase the extractable N, P, C and S concentrations, (ⅲ) and decrease greenhouse gas emissions. By using laboratory mesocosms, the nutrient (C, N, P and S) dynamics were monitored in an arable sandy clay loam soil receiving acidified and non-acidified cattle slurry in a 2-month incubation. Estimations of greenhouse gas emissions (CO2, CH4, N2O), soil-pore- water components (NO3−, NH4+, PO43−, SO42−, DOC, DON, pH) were performed on static mesocosms. In addition, a parallel set of mesocosms were used for soil extractions using distilled water and 0.5 M K2SO4. There were six treatments: (1) soil (control), (2) soil + slurry, (3) soil + acidified slurry (with H2SO4, pH =5.5), (4) soil + HCl, (5) soil + K2SO4, and (6) soil + K2SO4 + H2SO4. Our results showed that over the incubation, slurry acidification reduced soil pH by at least 0.4 units. Water soluble PO43−-P concentration was also reduced, whilst extractable DOC and NO3—N concentrations were increased; the latter as a result of stimulated N mineralization in the acidification treatments (3, 4 and 6). Differences in water soluble SO42- -S concentrations per treatment were not significant over time.Slurry acidification did not significantly affect N2O emissions but decreased net CO2 and CH4 emissions leading to an overall reduction in the soil's total greenhouse gas footprint (expressed as CO2e). We conclude that application of acidified slurry to soil can reduce soil pH by at least 0.4 pH units for up to 2-months before it is buffered back to the pH level of the soil that received the non-acidified slurry. In addition to increasing organic N mineralization with limited impacts on P and S dynamics of the soil and the slurry.

Mineralogical Investigation of Mg‐Sulfate at the Canaima Drill Site, Gale Crater, Mars

AbstractFor the first time on Mars, the crystalline magnesium‐sulfate mineral starkeyite (MgSO4‧4H2O) was definitively identified using the CheMin X‐ray diffraction instrument at Gale crater. At the Canaima drill site, starkeyite along with amorphous MgSO4‧nH2O are among the “polyhydrated Mg‐sulfates” interpreted in orbital reflectance spectra. Mg‐sulfates are good climate indicators as they are very responsive to changes in temperature and relative humidity. We hypothesize that, through evaporation, Mg‐sulfates formed at the end of brine evolution when ion concentrations became saturated and precipitated on the surface or near sub‐surface as either epsomite or meridianiite. These minerals were subsequently dehydrated later to starkeyite and amorphous MgSO4‧nH2O in response to a drier Mars. At Canaima, starkeyite is stable and would form during the warmer Mars summers. Due to very slow kinetics at the low Mars winter temperatures, starkeyite and amorphous MgSO4‧nH2O would be resistant to recrystallize to more hydrous forms and thus likely persist year‐round. During the course of analyses, starkeyite transforms into amorphous MgSO4‧nH2O inside the rover body due to the elevated temperature and greatly reduced relative humidity compared to the martian surface at the Canaima drill site. It is possible that crystalline sulfate minerals existed in earlier samples measured by CheMin but altered inside the rover before they could be analyzed. Starkeyite is most likely prevalent in the subsurface, whereas both starkeyite and amorphous MgSO4‧nH2O are likely present on the surface as starkeyite could partially transform into amorphous MgSO4‧nH2O due to direct solar heating.

Hydrochemical Characterization and Quality Assessment of Groundwater in the Southern Plain of Hebei Province, China

The purpose of this research was to understand the hydrogeochemical characteristics and assess the quality of phreatic and confined groundwater in southern Hebei Province. A total of 107 groundwater samples were collected, representing different aquifer conditions over the study area. Multivariate statistical analysis, hydrochemical maps, ionic ratio coefficients, geographic information system (GIS) and geochemical simulation were comprehensively and systematically used to reveal the hydrochemical characteristics of groundwater and its controlling mechanism. The results revealed that both phreatic (pH = 7.02–9.08) and confined groundwater (pH = 7.00–10.60) were slightly alkaline. The hydrochemical types were mainly present as the HCO3-Ca-Mg type in the western premontane area and mixed Ca-Mg-SO4-Cl and Na-Cl-SO4 types in the eastern plains. The hydrochemical composition was dominated by water–rock interactions of natural processes, including silicate weathering, dissolution of sulfate minerals (gypsum, anhydrite), and cation-exchange adsorption. Anthropogenic activities were the main factor causing NO3− content in some groundwater samples to exceed the geochemical baseline. The hydrogeochemistry of groundwater in different aquifers was significantly varied. The average contents of TH, TDS, Na+, Ca2+, Mg2+, Cl− and SO42− in phreatic aquifers were significantly higher than those in confined aquifers. The Entropy Weighted Water Quality Index (EWQI) results revealed that 17.78% of phreatic and 50% of confined water samples were meeting the purpose of drinking water. The groundwater samples with EWQI values exceeding 100 were mainly situated in the Handan urban area and the eastern region of Xingtai City, which should be avoided for direct utilization and needs to be improved through protection and management measures, to enhance the quality of groundwater. Correlation analysis showed that groundwater quality was significantly dominated by TH, TDS, Na+, Mg2+, Cl− and SO42− concentrations.

Mechanistic Intimate Insights into the Role of Hydrogen Sulfide in Alzheimer's Disease: A Recent Systematic Review.

In the rapidly evolving field of Alzheimer's Disease (AD) research, the intricate role of Hydrogen Sulfide (H2S) has garnered critical attention for its diverse involvement in both pathological substrates and prospective therapeutic paradigms. While conventional pathophysiological models of AD have primarily emphasized the significance of amyloid-beta (Aβ) deposition and tau protein hyperphosphorylation, this targeted systematic review meticulously aggregates and rigorously appraises seminal contributions from the past year elucidating the complex mechanisms of H2S in AD pathogenesis. Current scholarly literature accentuates H2S's dual role, delineating its regulatory functions in critical cellular processes-such as neurotransmission, inflammation, and oxidative stress homeostasis-while concurrently highlighting its disruptive impact on quintessential AD biomarkers. Moreover, this review illuminates the nuanced mechanistic intimate interactions of H2S in cerebrovascular and cardiovascular pathology associated with AD, thereby exploring avant-garde therapeutic modalities, including sulfurous mineral water inhalations and mud therapy. By emphasizing the potential for therapeutic modulation of H2S via both donors and inhibitors, this review accentuates the imperative for future research endeavors to deepen our understanding, thereby potentially advancing novel diagnostic and therapeutic strategies in AD.

Review on the development of multi- and hyperspectral remote sensing technology for exploration of copper–gold deposits

Most Copper (Cu) and Gold (Au) deposits are accompanied by hydrothermal alteration, generally related to ore-forming hydrothermal fluids. Multispectral and hyper-spectral Remote Sensing (RS) technology is essential for Cu-Au mineral prospecting. This paper provides an overview of RS data and the research situation and development tendencies of RS exploration technologies related to Cu-Au deposits. Initially, RS geologists applied the Band Ratio (BR) and Principal Component Analysis (PCA) to extract hydroxyl and iron anomalies from Landsat RS data to characterize the hydrothermal alterations associated with Cu-Au deposits. In the era of advanced spaceborne thermal emission and reflection radiometry (ASTER), clay minerals, sulfate minerals, carbonate minerals, silica minerals, and iron minerals can be identified because of three Visible and near-infrared bands (VNIR), six shortwave infrared bands (SWIR), and five Thermal Infrared bands (TIR). Alteration of mineral assemblages can be carried out to map alteration zones, which are essential for calibrating Cu-Au alteration zones, such as the typical alteration zoning characteristics of Porphyry Copper Deposits (PCD). Because of its high spectral resolution, Satellite hyperspectral RS can quantitatively map surface alteration minerals to indicate the exploration of Cu-Au deposits. RS geologists have extensively researched matching libraries and field spectra for Alteration Mineral Mapping (AMM). However, subpixel mineral information caused by low spatial resolution and atmospheric factors has an unavoidable influence on satellite hyperspectral RS AMM, and it is essential to use low-altitude unmanned aerial vehicle (UAV) hyperspectral RS. UAV hyperspectral AMM combined with geochemistry and geophysics is a means of prospecting and exploring Cu-Au deposits.

N-Alkane Biosignatures in a High Arctic Mars Analogue Gossan Deposit

If past life ever existed on Mars, what are the multiple ways it could have been preserved in the Martian geological record? This crucial question is becoming especially relevant the more we uncover about the planet’s ancient wet history. Different acidic and sulfur rich analog environments have been proposed that are comparable to the alteration environments of iron oxides and sulfate minerals on Mars. However, some authors have hypothesized that these past Martian environments might have been cold and semi-dry, similar to polar regions on Earth. As part of the T-MARS team, we studied reactive gossans in the Canadian High Arctic, on Axel Heiberg Island, as an analog environment to similar deposits on Mars. We hypothesized that n-alkane lipids could potentially be an important form of molecular fossils entombed in varying mineral assemblages of sulphates, iron oxides, and phyllosilicates in Arctic gossans, because of their excellent preservation potential relative to most other forms of organic molecules. To determine the preservation potential of lipids in mineralogically varying acidic sulfur rich gossan deposits, this study extracted and quantified n-alkane biomarkers from three different Arctic gossans with gas chromatography–mass spectrometry (GC-MS). Total organic carbon, pH, and mineralogy were also determined. Organic matter was found to be very low in all samples (<1% wt.%). N-alkane analysis also revealed preserved even-over-odd distribution patterns in short chain n-alkanes, most likely from a microbial source, along with evidence for long-chain n-alkanes with odd-over-even distribution from higher plant sources. The presence of these unique chemical biosignatures in low organic, highly acidic, and sulfur rich Mars analog gossans of varying maturity provides evidence that sulfur deposits linked to paleo hydrothermal systems on Mars can be promising targets for preserved organic biosignatures, specifically lipid n-alkanes. The significant diversity in biosignature patterns across samples of varying mineralogy, pH, and oxidation levels within each gossan suggests that n-alkane preservation varies on a small scale in these environments. These factors alone do not definitively account for the variability of n-alkane concentrations and distributions in this study, and additional investigations of these and other influencing factors are needed to determine which specific targets to choose for biosignature search on Mars in future space missions. This exploratory study provides novel insights into the lipid biosignature content in high Arctic Mars analogue gossan deposits.

The application of mixed stabilizing materials promotes the feasibility of the intercropping system of Gynostemma pentaphyllum/Helianthus annuus L. on arsenic contaminated soil

Intercropping technology and stabilizing materials are common remediation techniques for soils contaminated with heavy metals. This study investigated the feasibility of the Gynostemma pentaphyllum (G. pentaphyllum)/Helianthus annuus L. (H. annuus) intercropping system on arsenic (As) contaminated farmland through field and pot experiments and the regulation of plant As absorption by the application of mixed stabilizing materials in this intercropping system. Field experiments demonstrated that intercropping with H. annuus increased the As concentration in G. pentaphyllum leaves to 1.79 mg kg−1 but still met the requirements of the national food standard of China (2 mg kg−1) (GB2762-2017). Meanwhile, G. pentaphyllum yield in the intercropping system decreased by 15.09%, but the difference was insignificant (P > 0.05). Additionally, the As bioconcentration (BCA) per H. annuus plant in the intercropping system was significantly higher than that in the monoculture system, increasing by 76.37% (P < 0.05). The pot experiment demonstrated that when granite powder, iron sulfate mineral, and "Weidikang" soil conditioner were applied to the soil collectively, G. pentaphyllum leaf As concentration in the intercropping system could be significantly reduced by 42.17%. Rhizosphere pH is the most crucial factor affecting As absorption by G. pentaphyllum in intercropping systems. When these three stabilizing materials were applied simultaneously, the As bioaccumulation (BCA) per H. annuus plant was significantly higher than that of normal intercropping treatment, which increased by 71.12% (P < 0.05), indicating that the application of these stabilizing materials significantly improved the As removal efficiency of the intercropping system. Dissolved organic carbon (DOC) concentration in the rhizosphere soil is the most pivotal factor affecting As absorption by H. annuus. In summary, the G. pentaphyllum-H. annuus intercropping model is worthy of being promoted in moderately As polluted farmland. The application of granite powder, iron sulfate mineral, and "Weidikang" soil conditioner collectively to the soil can effectively enhance the potential of this intercropping model to achieve "production while repairing" in the As polluted farmland.

Use of Hydrogeochemistry and Isotopes for Evaluation of Groundwater in Qilian Coal Base of China.

The Jiangcang Basin is an important mining area of the former Qilian Mountain large coal base in Qinghai Province, and understanding the groundwater circulation mechanism is the basis for studying the hydrological effects of permafrost degradation in alpine regions. In this study, hydrogeochemical and multiple isotope tracer analysis methods are used to understand the chemical evolution and circulation mechanisms of the groundwater in the typical alpine region of the Jiangcang Basin. The diversity of the groundwater hydrochemistry in the study area reflects the complexity of the hydrogeochemical environment in which it is located. The suprapermafrost water and intrapermafrost water are recharged by modern meteoric water. The groundwater is closely hydraulically connected to the surface water with weak evaporation overall. The high δ34S value of deep groundwater is due to SO4 reduction, and SO4 2--rich snow recharge with lixiviated sulfate minerals are the main controlling factor for the high SO4 2- concentration in groundwater. According to the multivariate water conversion relationships, it reveals that the river receives more groundwater recharge, suprapermafrost water is recharged by the proportion of meteoric water, which is closely related to the mountainous area at the edge of the basin, while intrapermafrost water is mainly recharged by the shallow groundwater. This study provides a data-driven approach to understanding groundwater recharge and evolution in alpine regions, in addition to having significant implications for water resource management and ecological environmental protection in coal bases of the Tibetan Plateau.

Calcium sulfates in planetary surface environments

Calcium sulfates play a key role in both industrial processes and the global sulfur cycle. In arid to hyper-arid planetary surface environments, they can be used to assess the availability of water to the environment. Yet, the processes through which calcium sulfate minerals (i.e. gypsum, bassanite, anhydrite) and the anhydrous γ-CaSO4 form and transform remain insufficiently understood. Especially the dissolution-reprecipitation reaction from gypsum to anhydrite has to this date been achieved in the laboratory only under very specific conditions.Recent evidence suggests the importance of solution flow as opposed to batch reactions in aiding the precipitation of anhydrite at room temperature. Our own results, however, clearly show, that solution flow alone cannot be the sole catalyst. In light of the recent abundance of research towards the nucleation and crystallization of calcium sulfates, we present this review in an attempt to summarize and contextualize these new results and to identify necessary directions for further research with focus on conditions of arid and hyper-arid planetary environments.

Оцінка сучасного гідрохімічного стану деяких рибогосподарських ставів Київщини

Purpose. To assess the quality of the hydrochemical regime of fishponds, the territory of which suffered massive missile strikes or was directly a combat zone or close to the front line. Methodology. Chemical parameters of water including the content of ammonium nitrogen, nitrites, nitrates, phosphates and total iron were measured by the photometric method, while chloride concentration of chlorides by the argentometric titration method. The hydrogen indicator (pH) was determined electrometrically, and sulfate content and mineralization by the gravimetric method. All the above-mentioned methods are generally accepted in the comprehensive assessment of the ecological state of fishponds. Findings. The total amount of mineral salts dissolved in water was studied and analyzed in laboratory conditions, namely: the concentrations of calcium, magnesium, chlorine, bicarbonate ions and sulfate ions. The determined permanganate oxidizability in the investigated ponds exceeded the normative values by 72, 49, 31, and 42%, respectively. The concentration of nitrates ranged from 19.96 to 6.34 mg N/dm3, nitrites from 0.33 to 0.11 mgN/dm3, which indicates the intensity of decomposition of organic substances and indicates a certain degree of contamination of ponds. The amount of total iron in the studied ponds ranged from 1.98 to 1.17 mgFe/dm3, respectively. A slight increase in mineral phosphorus in ponds No. 1 and No. 2 was established by 31 and 26%, respectively, which can probably be related to both the decomposition of zooplankton and the input of pollutants from the outside from the surrounding areas. The obtained results of the laboratory analysis of the chemical composition of water samples as well as their comparison with the normative values for water bodies used for aquaculture provide a basis for assessing the current hydrochemical state of the investigated ponds of Kyiv region Originality. For the first time, a hydrochemical analysis of fishponds in Kyiv Region was conducted, the territory of which suffered massive missile strikes or was directly a combat zone or close to the front line. Practical value. The obtained results will contribute to a better understanding of the current ecological state of fishponds in Kyiv region. Keywords: water body, chemical analysis of water, toxic substances, ecological condition.

Gamma-emitting radionuclides in therapeutic muds of the Euganean Thermal District (Padua, Italy)

Mud therapy is a therapeutic tool which uses natural materials available in the environment for healing purposes (clays and thermal water). The use of natural remedies increases the compliance to the cure, and their success is increasing in the last decades, all over the world. As natural matters, also muds have a wide range of composition, so, their use for healing requires appropriate knowledge.One of the most important world reference area for mud therapy has been accessed for sampling in different thermal centers (28) and also the exploiting site of raw clay has been studied. High resolution gamma spectrometry measurements have been acquired, compared with previous published data and discussed considering other compositional parameters.A clear increase of radionuclides of the 238U series characterize therapeutic muds respect to raw materials, 226Ra in particular. The scavenging of Ra from thermal waters is considered to occur after the precipitation of sulfate minerals (gypsum, barite) into the mud matrix, and several lines of evidence suggest that the repeated contact with thermal water (mud recycling) enhance the enrichment of Ra. A different scenario can be drawn for workers and for patients, as their contact with the mud is different for type and time. The dose arising from working in the area of therapeutic muds preparation and the dose to the skin of patients have been calculated.Even if Euganean therapeutic muds are richer in 226Ra respect to other similar materials, no radiological hazards emerged for workers who manage the preparation area, even in the most cautionary scenario. Also for patients, the contribution of Euganean mud therapy to the annual equivalent dose to skin is negligible, according to the cautionary elaboration done. Also considering literature data on the transcutaneous passage of chemical elements with geochemical affinity with Ra, no radiological hazard is detectable.

Characterization of aqueous alteration and formation of salty exposures at Ius Chasma, Mars

Intriguing outcrops in Ius Chasma provide a window into past aqueous processes in Valles Marineris, Mars. Hydrous sulfate minerals are abundant throughout this region, but one area in Ius Chasma includes phyllosilicates, opal, and additional materials with unusual spectral features. This study at Geryon Montes, an east-west horst that divides Ius Chasma into a northern and southern canyon, exploits recent advances in image calibration and feature extraction techniques for analysis of hyperspectral images acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Specifically, a unique spectral “doublet” feature with absorptions at 2.21–2.23 and 2.26–2.28 μm is isolated at the border of phyllosilicate-bearing and sulfate-bearing regions in Ius Chasma and surveyed to characterize outcrops that may represent a changing climate on Mars. We document and map three distinct forms of this “doublet” material in relation to phyllosilicates and opal. Analyses of compositional maps derived from CRISM overlain on High Resolution Stereo Camera (HRSC) and High Resolution Imaging Science Experiment (HiRISE) imagery has revealed the presence of these hydrated outcrops along the wall rocks below a breach in the Geryon Montes, bordering a canyon containing abundant hydrated sulfates. Our investigation supports formation of these unique alteration phases through acid alteration of ancient smectites in the wall rock as the sulfate brine overflowed the south canyon of Ius Chasma at the breach in Geryon Montes and penetrated the deeper northern canyon.

Surface modification of NF membrane via an environmentally friendly and rapid approach for desalination Process: Performance and stability evaluation

In this study, an environmentally friendly and rapid surface modification method known as surface mineralization was adopted to alter the polyamide (PA) layer of commercial NF270 thin film composite (TFC) membrane, aiming to improve its characteristics for enhanced desalination process. An alternate soaking process was applied on the membrane surface by using barium chloride solution and sodium sulfate solution at varying concentrations (0.01 M, 0.05 M and 0.1 M). The reaction of these two salts can form a layer of barium sulfate (BaSO4) minerals atop the PA layer via an ionic interaction. Our result revealed that the best-performing membrane could be developed using salt solutions at 0.05 M with its water contact angle descended to 33.5° compared to the pristine membrane of 46.4°. Furthermore, the surface roughness of the BaSO4-mineralized membrane was reported to be higher than the pristine membrane. The increase in surface roughness together with improved surface hydrophilicity yielded the BaSO4-mineralized membrane to exhibit 12% higher water flux than the pristine membrane. Nonetheless, the difference in Na2SO4 rejection before and after surface mineralization was not found to be statistically significant owing to the high Na2SO4 rejection of the control membrane. The BaSO4-mineralized membrane also achieved excellent performance in filtering solutions containing sodium alginate and showed very stable salt rejection for multiple cycle of combined chemical cleaning and water filtration process. These results highlighted the potential of the surface mineralization process in overcoming the trade-off effect between water flux and selectivity of TFC membrane.

Supergene Hydrous Sulfates in the Tuolugou Co-Au Deposit, Northern Qinghai–Tibet Plateau: Implications for Genetic Mechanism and Exploration

Supergene hydrous sulfate minerals form through the oxygenation and weathering of primary sulfides. In the Qinghai–Tibet Plateau region, with an alpine and dry environment, hydrous sulfate minerals oxidized from pyrite-bearing ore bodies provide important clues regarding the mineralization and environment. The Tuolugou sedimentary-exhalative (SEDEX) Co-Au deposit is located in the East Kunlun metallogenic belt of the northern Qinghai–Tibet Plateau in China. In the mining district, pyrite is the prevalent Co-hosting sulfide mineral, and is partially exposed on the surface to weathering and oxidation. Herein, we document the mineral assemblages in the supergene oxidation zone in the Tuolugou deposit, probe the genesis of supergene assemblage, and explore the implications for exploration. Three zones can be recognized in the oxidation zone of the Tuolugou deposit, including the outer zone (natrojarosite), intermediate zone (rozenite and aplowite), and inner zone (roemerite and melanterite). The mechanism of oxidation under aerobic and anaerobic conditions, as well as zoning with different oxidation degrees, are described in detail. Hydrous sulfates such as natrojarosite can be used as possible indicators of the exploration of albitite-related SEDEX deposit in this region.

Detection of dsrAB operon expression in Desulfotalea psychrophila cells subjected to simulated Martian conditions of temperature and regolith's sulphate minerals composition

AbstractDiscoveries of transient liquid water in the Martian polar caps and the presence of liquid lakes and subsurface oceans in icy satellites have increased the interest of scientists in the capabilities of terrestrial extremophiles to grow and remain metabolically active in these extreme environments. The principal goal of this research is to understand the metabolic capacity of the anaerobic psychrophile, Desulfotalea psychrophila, cultured at subfreezing temperatures in media containing various concentrations of sulphate minerals. In this regard, our experiments focused on the detection of D. psychrophila survival and active metabolism, employing a biochamber that can recreate Martian temperatures. Using standard bacteriological methods for determining growth, combined with molecular and enzymatic determination of sulphate reduction, we have found that D. psychrophila is capable to carry out biological processes at temperatures down to −5°C, at concentrations that range from 0.35 to 18 wt% of MgSO4, 0.1 wt% of CaSO4 and 10 to 14 wt% of FeSO4 in which the highest sulphate concentration gradually returned the biosynthetic rate to basal limits, and the lowest temperature decreased bacterial cell division. These chemical salts, whose ions are classified as chaotropes, are known to act by maintaining water molecules in liquid state at subfreezing temperatures and by altering the stability of cellular components. This ‘chaotropic effect’ could potentially benefit the microbial metabolic activity up to a concentration in which cellular viability is jeopardized. Consequently, our hypothesis is directed towards the detection of metabolic activity as an indirect measurement of the potential influence of these ions in the flexibility/functionality of biological structures that at cold temperatures are highly rigid, compact and partially/non-functional due to water freezing. Studies of this type of microorganism are critical considering the possibility of survival and colonization of psychrophilic sulphate reducers in other planets and icy satellites.

The Study of the Biotechnology of Sulfur Minerals

Abstract The paper presents the direct and indirect mechanism of action of different types of microorganisms in the process of chemical-bacterial solubilization of sulfuric minerals. The discovery of some bacteria that favor the dissolution of metals, increasing the speed of the process up to 500,000 times, proved to be able to improve the parameters of hydrometallurgy and create new possibilities for its application in the recovery of useful elements from different minerals and waste. The mechanism of the chemical-bacterial mineral solubilization process does not proceed according to a unitary mechanism, but corresponds to different mechanisms depending on the nature of the metal, the nature of the ore, the microorganisms and the physical-mechanical conditions in which the bacterial culture acts.

Controls on Barite (BaSO4) Precipitation in Unconventional Reservoirs.

Barite (BaSO4) precipitation is one of the most ubiquitous examples of secondary sulfate mineral scaling in shale oil and gas reservoirs. Often, a suite of chemical additives is used during fracturing operations to inhibit the accumulation of mineral scales, though their efficacy is widely varied and poorly understood. This study combines experimental data and multi-component numerical reactive transport modeling to offer a more comprehensive understanding of the geochemical behavior of barite accumulation in shale matrices under conditions typical of fracturing operations. A variety of additives and conditions are individually tested in batch reactor experiments to identify the factors controlling barite precipitation. Our experimental results demonstrate a pH dependence in the rate of barite precipitation, which we use to develop a predictive model including a pH-dependent term that satisfactorily reproduces our observations. This model is then extended to consider the behavior of three major shale samples of highly variable mineralogy (Eagle Ford, Marcellus, and Barnett). This data-validated model offers a reliable tool to predict and ultimately mitigate against secondary mineral accumulation in unconventional shale reservoirs.

Structural and Chemical Diversity and Complexity of Sulfur Minerals

The chemical and structural diversity of minerals containing sulfur as an essential mineral-forming element has been analyzed in terms of the concept of mineral systems and the information-based structural and chemical complexity parameters. The study employs data for 1118 sulfur mineral species approved by the International Mineralogical Association. All known sulfur minerals belong to nine mineral systems, with the number of essential components ranging from one to nine. The chemical and structural complexity of S minerals correlate with each other; that is, on average, chemical complexification results in structural complexification. The minerals with S–O bonds (sulfates and sulfites) are more complex than those without S–O bonds (sulfides and sulfosalts). However, the most complex sulfur mineral known so far is incomsartorite, Tl6Pb144As246S516, a sulfosalt. The complexity-generating mechanism in sulfides and sulfosalts is the complex combination of different modules excised from parent PbS or SnS archetypes with the subsequent formation of superstructures. The drivers for structural complexity in sulfates are more diverse and, in addition to modular construction and superstructures, also include a high hydration state, the presence of polyatomic clusters, and framework complexity. The most complex Martian minerals are most probably halotrichite-group minerals. The chemical and structural complexity increases with the passage of geological time with the formation of the most complex sulfosalts at Lengenbach (Swiss Alps) triggered by life (activity of sulfur-reducing bacteria).

Organic matter enrichment mechanism in saline lacustrine basins: A review

Organic‐rich shale in saline lacustrine basins holds significant importance as a source rock for conventional hydrocarbon exploration and has emerged as a prominent target for unconventional hydrocarbon exploration and development in recent years. Based on saline lacustrine basins, this paper provides a summary of the organic matter enrichment mechanisms in saline lacustrine basins, considering sedimentary characteristics, biological activities, factors for the organic matter enrichment and consumption, and hydrocarbon generation. The implications for these factors are discussed in relation to the distribution prediction of high‐quality lacustrine shale district settings and the exploration and development of shale oil. Saline lacustrine basins undergo distinct evolutionary stages, each corresponding to different sedimentary stages involving carbonate minerals, sulphate minerals, and alkaline minerals. Moreover, these basins exhibit diverse biological types and experience extensive biological activities. The prosperity of organisms and the accumulation of sedimentary organic matter are ensured by halophilic organisms. Organic matter enrichment in saline lacustrine basins is influenced by two main aspects: the primary productivity of organic matter, which is promoted by the proliferation of halophilic organisms, and the efficient preservation of organic matter facilitated by the strong reducing environment resulting from promoted water salinity stratification. The organic matter consumption in saline lacustrine basins involves bacterial sulphate reduction (BSR) in the early stages, thermochemical sulphate reduction (TSR) in the late stages, and dilution of salt minerals with higher depositional rates. of the presence of salt beds and saline minerals positively influences hydrocarbon generation and expulsion in organic‐rich shale within saline lacustrine deposition. Consequently, continental saline lacustrine basins in China offer favourable conditions for the formation of organic‐rich shale and present broad prospects for the exploration of shale oil and gas resources.