Fraction Of Sulfur Research Articles

Impacts of spatial expansion by Phragmites australis on spatiotemporal variation of sulfur fractions in marsh soils of the Min River estuary, Southeast China

To investigate the impacts of spatial expansion by Phragmites australis on spatiotemporal variations of sulfur (S) fractions in marsh soils of the Min River estuary (Southeast China), the contents of total sulfur (TS) and inorganic sulfur (IS) fractions (Water-Soluble-S, W-S-S; Adsorbed-S, A-S; HCl-Soluble-S, H-S-S; and HCl-Volatile-S, H-V-S) were determined in soils of Cyperus malaccensis marsh (before expansion, BE stage), P. australis-C. malaccensis marsh (during expansion, DE stage) and P. australis marsh (after expansion, AE stage) by space-for-time substitution method. Results showed that the expansion of P. australis greatly altered the spatiotemporal variations of TS and IS fractions in marsh soils. The TS contents in soils at AE stage were significantly lower than those at DE and BE stages throughout a year (p < 0.01). Higher levels of W-S-S, A-S, H-S-S and total inorganic sulfur (TIS) generally occurred in soils at DE and AE stages, whereas higher values of H-V-S were observed in soils at BE stage. Although P. australis expansion did not alter the temporal variations of TS stock in soils greatly, the values during autumn and winter were generally higher than those in spring and summer (p < 0.05). The highest TIS stocks in soils of different expansion stages were observed in spring, while the lowest values occurred in summer. The expansion of P. australis significantly increased the IS supply capacity of soils and, compared with the BE stage, stocks of W-S-S, A-S, H-S-S and TIS in soils of all sampling seasons at DE and AE stages increased by 51.40 %, 50.76 %, 63.35 %, 50.52 % and 20.00 %, 31.46 %, 42.93 %, 27.56 %, respectively. It was worth noting that stocks of H-V-S in soils at DE and AE stages showed a decreasing trend compared to the BE stage, implying that the expansion of P. australis might reduce the production of sulfides. This paper found that, compared with C. malaccensis, the increased available IS stocks in soils might be an effective strategy for P. australis to maintain its expansion advantage and the decreased volatile-S in soils might be more favorable for boosting its competitiveness. Our study provided valuable information for understanding the interspecific competition mechanism between P. australis and C. malaccensis. Next step, in order to protect the diversity of marsh vegetations in the Min River estuary, effective measures should be taken to suppress the rapid expansion of P. australis.

Changes in land use practices influence soil sulfur fractions and their bioavailability

Changes in land use practices may affect the distribution of soil sulfur (S) fractions and their bioavailability. Therefore, this study was undertaken to assess the influence of different land use changes on the distribution of soil S fractions and their bioavailability for plant nutrition. Soil samples from farmers’ fields with different land use practices such as rice-mustard-jute (R-M-J), rice-lentil-jute (R-L-J), rice-lentil-sesame (R-L-S), rice-vegetable-jute (R-V-J), and rice-potato-green gram (R-P-G) were collected and analyzed for different fractions of S. The bioavailability of S was assessed by extracting the soil with six different extractants (acidic, neutral, and alkaline) with different extraction modes and chemistry. The results showed that changes in land use practices could influence the distribution of soil S fractions and their bioavailability. Organic S was the dominant fraction, accounting for 93.5% of total S across land use practices. The inorganic S fraction (water-soluble, sorbed, and occluded) varied significantly among the land use practices. Among the inorganic fractions, the water-soluble fraction was the dominant fraction across the land use practices. The bioavailability of S, as assessed by different chemical extractants, was in the following order: sodium hydrogen carbonate (NaHCO3) &amp;gt; mehlich-3 &amp;gt; ammonium bicarbonate-diethylenetriamine penta-acetic acid (AB-DTPA) &amp;gt; ammonium acetate-acetic acid (NH4Ac-HOAc) &amp;gt; calcium dihydrogen phosphate {Ca(H2PO4)2} &amp;gt; calcium chloride (CaCl2). By establishing relationships between extractable S and soil S fractions, it was observed that all the extractants could obtain S from the water-soluble, sorbed, and organic S fractions, with little extractability from the occluded fraction. Among the extractants tested, mehlich-3 extracted a similar amount of S corresponding to the inorganic fraction across the land use practices. It also maintained positive relationships with different fractions of S, and as a multi-nutrient extractant, its use in routine soil testing can be recommended.

Distribution and Characterization of Sulphur fractions in Entisols, Inceptisols and Alfisols Soil Orders of India

The present investigation was conducted to distribute and characterization of different Sulphur (S) fractions in selected soil orders of India. Soil samples were collected from cultivated fields in different states of India, covering West Bengal, Jharkhand, Bihar, Uttar Pradesh, Uttarakhand, and Himachal Pradesh. These states belong to the soil orders Entisols, Inceptisols, and Alfisols. A total of two hundred seventy composite soil samples were collected from ten locations of each order, representing three depths: 0-15 cm, 15-30 cm, and 30-45 cm, with thrice replication. After analyzing the various sulfur fractions, the results showed that there was no distinct distribution of sulfur reported in the various locations. In Entisols soil order, non-sulphate sulfur contributes highest fraction with a mean of 2744.99 mg kg-1 while lowest contribution was found in available sulfur with a mean of 25.24 mg kg-1 of total S followed by organic sulfur (112.54 mg kg-1), adsorbed sulfur (97.79 mg kg-1). A similar pattern was observed in Inceptisols and Alfisols soil orders. Available S was positive and significantly correlated with organic Sulphur in Entisol and Inceptisol while negative correlated with remaining fraction of S. Based on the sulfur availability index, the dominant fraction of sulfur in all three soil orders was non-sulfate sulfur.

Effects of particle size on the pyrolysis of waste tires during molten salt thermal treatment

Recently, waste tires gain a growing recognition of the potential as value-added fuel via pyrolysis. In the present study, molten salt was proposed to be used for the waste tires pyrolysis, aims to enhance heat transfer efficiency, and then reduce energy input for the mechanical shredding of waste tires into small particles before pyrolysis. In detail, the conversion and products formation behavior of two waste tires (of different particle sizes) were compared by a constructed molten salt thermal treatment system. Results show that H2 and CH4 contents of the pyrolysis gas increased substantially, and smaller tire particles produced more H2 and CH4 (up to 500%), while CO2 content dropped to zero. Also, the contents of benzene increased remarkably with molten salt added (growth rate is between 1100% and 1800%) for electro-mobile tires, while caprolactam was disappeared. Specifically, benzene yield increases and then decreases with increasing particle size. In addition, molten salts were also effective in removing sulfur and ash from pyrolytic char, with more than 60% of the sulfur fraction being removed. These findings could provide theoretical support for the development of low-cost thermal treatment technology for waste tires.

Degradation Mechanisms of a Li—S Cell using Commercial Activated Carbon

&lt;p&gt;In lithium–sulfur (Li–S) batteries, encapsulation of sulfur in activated carbon (AC) materials is a promising strategy for preventing the dissolution of lithium polysulfide into electrolytes and enhancing cycle life, because instead of solid–liquid–solid reactions, quasi-solid-state (QSS) reactions occur in the AC micropores. While a high weight fraction of sulfur in S/AC composites is essential for achieving a high energy density of Li–S cells, the deterioration mechanisms under such conditions are still unclear. In this study, we report the deterioration mechanisms during charge–discharge cycling when the discharge products overflow from the AC. Analysis using scanning electron microscopy and energy-dispersive X-ray spectrometry confirms that the sulfur in the S/AC composites migrates outside the AC as cycling progresses, and it is barely present in the AC after 20 cycles, which corresponds to the capacity decay of the cell. Impedance analysis clearly shows that the electrical resistance of the S/AC composite and the charge-transfer resistance of QSS reactions significantly increase as a result of sulfur migration. On the other hand, the charge–discharge cycling performance under limited-capacity conditions, where the discharge products are encapsulated inside the AC, is extremely stable. These results reveal the degradation mechanism of a Li–S cell with micro-porous carbon and provide crucial insights into the design of a S/AC composite cathode and its operating conditions needed to achieve stable cycling performance.&lt;/p&gt;

Characterization of Soil Properties and Their Relationship with Various Sulphur Fractions in Groundnut Farming Regions of Bikaner District, India

An exploratory survey was conducted in Bikaner district during the 2015-16 kharif season to study the sulphur fractions and other soil properties in groundnut growing areas. 40 farmers from four tehsils (Lunkaransar, Shri Dungargarh, Nokha, and Kolayat) were selected for the study. Soil samples were collected and analyzed for pH, EC, CaCO3, organic carbon, soil texture, available nutrients (N, P2O5, K2O, S), and sulphur fractions. The results showed that the soils were sandy, loamy sand, and sandy loam in texture and alkaline in -pH. The majority of soils were calcareous with low organic carbon content. The available nitrogen was found to be low while available P2O5 and K2O were medium. The distribution of different forms of sulphur in soil was found to be strongly dependent on soil characteristics such as clay content, silt and organic carbon content. It is noted that for more productive growth of groundnut better fertilizer practices along with organic manure should be practiced so as to improve OC status as well as compensate for lower water holding capacity of sandy soils.

A study on the desulfurization of sulfidic mine tailings for the production of a sulfur-poor residue

The mining industry generates large amounts of tailings every year. The most common destination for the tailings is deposition in tailings storage facilities (TSFs), which can have enormous dimensions. The management and storage of such large volumes of material pose many challenges in terms of dam stability and immobilization of hazardous contaminants that represent human-health and environmental risks, particularly for sulfide-containing materials. In addition, considerable amounts of precious and base metals can be lost in the tailings. Due to the economic value and growing industrial demand for precious and base metals, tailings may therefore be potential sources of secondary raw materials. This contribution investigates the flotation of pyrite-rich tailings, containing residual chalcopyrite, galena, and sphalerite, and high amounts of ultrafine particles. Flotation was used to recover the sulfide minerals and generate tailings with low sulfur content. The Cu-Pb-Zn-rich product could go to further treatment (e.g. (bio)hydrometallurgy) to recover the metals, while the low sulfur fraction could be used in the civil construction industry. Automated mineralogy (MLA) was used to provide quantitative mineralogical and textural data. Bench-scale experiments were performed by combining classic flotation and floc flotation (flotation of flocs of targeted minerals). Flotation of the material as received, as well as after classification into two fractions was performed. The samples as received and the coarser fraction (+37 µm) underwent classic flotation, while the finer fraction (−37 µm) was processed either by using the classic or the floc flotation approach. The flotation of the coarser particles provided higher sulfide recoveries, higher combined Cu-Pb-Zn grades in the concentrate (3.66%), cleaner residues (1.6% S), faster flotation rates, and reduced reagent consumption. Likewise, the results from the fine particle flotation allowed lower S content in the residues (3.4% S) as compared to the flotation of the original material. The results of the use of floc flotation for the finer fraction show an increase in the mass pull with a slight increase in the recovery of sulfides. Overall, the development of a route to process the tailings proved to be promising and the use of a two-route approach indicates advantages as compared to a single route.

Microwave-assisted solvent deasphalting of heavy fuel oil and process parameters optimization

As petroleum recovery has progressed historically, the portion of heavier crudes and bottom of the barrel residues from the refining process has increased. These crudes are challenging to process, leaving vacuum residues with large fractions of ash and refractory sulfur due to high asphaltene content. Asphaltenes are known to form coke in catalytic upgraders and deactivate refining catalysts. Asphaltenes, which are present in significant amounts in heavy crudes, are the cause of reduction of combustion efficiency, clogging of refinery pipes, and particulate matter emissions. Asphaltenes can be removed from heavy crudes by solvent deasphalting. But the requirement of a high solvent to oil ratio limits its commercial viability. To lower the requirement of solvent, this study investigates deasphalting of heavy fuel oil (HFO) with n-heptane, n-hexane, and n-pentane by microwave-assisted, ultrasound-assisted, and supercritical solvent deasphalting methods. Among the different methods investigated, the microwave-assisted method was found to be more efficient and removed 88 and 80 wt% of asphaltenes from HFO with heptane and hexane, respectively. Microwave irradiation selectively heats asphaltenes in microwave transparent non-polar solvents and increases the degree of collision of asphaltenes for aggregation and thus precipitation. Besides, resins are readily solubilized by the solvent under microwave heating and thus they are unable to act as peptizing agents of asphaltenes. The optimization of process parameters such as solvent to HFO ratio, microwave power, and holding time was investigated for microwave-assisted deasphalting using Central Composite Design (CCD) and artificial neural network (ANN). The optimum removal of asphaltene was observed when the solvent to HFO ratio, microwave power, and holding time were kept at 3, 150 W, and 20 min, respectively. Deasphalting also significantly improved the quality of HFO by dropping the viscosity along with the sulfur and nitrogen contents of HFO. The outcomes of this study are significant for the petrochemical industry as potentially improved crude oil processing with lower solvent to HFO ratios can be achieved in a more effective, economical manner using microwave assistance.

Sulfur fertilization enhanced productivity and profitability of popular kenaf varieties

Kenaf, also known as Deccan hemp (Hibiscus cannabinus L.) is the one of the most important, hardy and economic bast fiber industrial crops. Sulfur plays a significant role in determining yield and quality of fiber crops. However, the effect of sulfur application on yield, nutrient uptake in kenaf varieties, agronomic efficiency, apparent S recovery, and nutrient availability and sulfur fractions is still unclear. Thus, the present investigation was carried out to study the effect of sulfur (S) fertilization (S0= Control, S15=15kg S ha−1, S30=30kg S ha−1, S45=45kg S ha−1) on fiber yield, nutrient uptake, nutrient availability and S fractions of experimental soil and to screen the kenaf varieties (‘JBM-2004-D’, ‘MT-150’, ‘AMC-108’ and ‘HC-583’) for higher S use efficiency and increased productivity. Compared to control (S0), S45 treatment significantly increased fiber yield of kenaf by 37%. MT-150 produced the highest fiber yield (2.61 t ha−1). Among the S levels, S45 exhibited lowest value of agronomic efficiency (16.5 kg kg−1 S), apparent S recovery (18.7%) and highest value of nutrient uptake in kenaf. Results also revealed that nutrient availability (nitrogen, phosphorus and potassium) increased with increase in S levels at all soil depths and the nutrient status decreased with depth. Sulfur fractions (total S, organic S, adsorbed S, plant available S) increased with increasing S levels and followed the order as organic S > non-sulfate S > adsorbed S > plant available S. In addition, organic sulfur contributed 63–74% of total sulfur. Thus, the results suggest that by selecting appropriate variety and level of sulfur (@ 30 kg ha−1) for kenaf cultivation farmers can obtain higher fiber yield for sustainable crop production.

Pioglitazone treatment increases the cellular acid-labile and protein-bound sulfane sulfur fractions

BackgroundIron-sulfur clusters play a central role in cellular function and are regulated by the ATM protein. Iron-sulfur clusters are part of the cellular sulfide pool, which functions to maintain cardiovascular health, and consists of free hydrogen sulfide, iron-sulfur clusters, protein bound sulfides, which constitute the total cellular sulfide fraction. ATM protein signaling and the drug pioglitazone share some cellular effects, which led us to examine the effects of this drug on cellular iron-sulfur cluster formation. Additionally, as ATM functions in the cardiovasculature and its signaling may be diminished in cardiovascular disease, we examined pioglitazone in the same cell type, with and without ATM protein expression. MethodsWe examined the effects of pioglitazone treatment on the total cellular sulfide profile, the glutathione redox state, cystathionine gamma-lyase enzymatic activity, and on double-stranded DNA break formation in cells with and without ATM protein expression. ResultsPioglitazone increased the acid-labile (iron-sulfur cluster) and bound sulfur cellular fractions and reduced cystathionine gamma-lyase enzymatic activity in cells with and without ATM protein expression. Interestingly, pioglitazone also increased reduced glutathione and lowered DNA damage in cells without ATM protein expression, but not in ATM wild-type cells. These results are interesting as the acid-labile (iron-sulfur cluster), bound sulfur cellular fractions, and reduced glutathione are low in cardiovascular disease. ConclusionHere we found that pioglitazone increased the acid-labile (iron-sulfur cluster) and bound sulfur cellular fractions, impinges on hydrogen sulfide synthesis, and exerts beneficial effect on cells with deficient ATM protein signaling. Thus, we show a novel pharmacologic action for pioglitazone.

Changes in Soil Sulphur Fractions as Influenced by Nutrient Management Practices in Mulberry

Sulphur (S) plays a vital role in improving the quality of mulberry leaves because of its involvement in protein synthesis. The knowledge of different pools of S in soils and its bioavailability for mulberry nutrition is thus, required for optimizing S fertilization. Hence, the present study was designed to ascertain the influence of chemical fertilizer and farmyard manure (both are S sources) on S fractions and its bioavailability in soils. In this regard, four nutrient management practices viz., control (without any chemical fertilizers and organic manures), recommended doses of N, P and K fertilizers (100% RDF), 80% RDF, 60% RDF with four mulberry varieties viz., V-1, G-4, AGB-8 and MSG-2 besides a fallow were considered for the study. Furthermore, the bioavailability of S in soils was tested using four commonly used chemical extractants viz., CaCl2, NaHCO3, AB-DTPA and Mehlich-3 (with different modes and chemistry of extraction). Organic S was the dominant fraction in the experimental soils accounting for 94.7% of total soil S while the inorganic fraction constituted only 5.3% that includes water soluble, sorbed and carbonate occluded S. Lowest amount of organic S content in soils of unmanured control (579.6 mg kg−1) was observed while the 100% RDF treatment (673.2 mg kg−1) maintained a higher content of soil organic S. High amount of sorbed and occluded S was observed in control plot compared to other fertilizer treatments (100% RDF, 80% RDF and 60% RDF). There was a gradual decline in soil S fractions when the fertilizer inputs were reduced to 60% suggesting that recommended doses of fertilizer inputs could maintain the soil S fractions. In addition, the extractable fractions of S were influenced by the fertilizer application rates and the extractability of all four extractants decreased with the reduction in fertilizer inputs. The amount of S extracted by all four chemical extractants followed the order of NaHCO3 &gt; Mehlich-3 &gt; AB-DTPA &gt; CaCl2 across the tested soils. Dynamic relationships among the extractants indicated that they could extract the S from the same pools in soil. Of the four extractants tested for evaluating plant available S, Mehlich-3 showed a higher degree of correlations with plant tissue S concentration and applied S through chemical fertilizers and farmyard manure. Furthermore, it could maintain strong correlations with water soluble and organic S fractions which were found to contribute significantly to plant S concentration. Thus, Mehlich-3 can be recommended for the assessment of bioavailable S for the nutrition of mulberry.

SO2 Photodissociation at 193 nm Directly Forms S(3P) + O2(3Σg-): Implications for the Archean Atmosphere on Earth.

It is well-documented that photodissociation of SO2 at λ = 193 nm produces O(3Pj) + SO X(3Σ-). We provide experimental evidence of a new product channel from one-photon absorption producing S(3Pj) + O2 X(3Σg-) in 2-4% yield. We probe the reactant and all products with time-resolved photoelectron photoion coincidence spectroscopy. High-level ab initio calculations suggest that the new product channel can only occur on the ground-state potential energy surface through internal conversion from the excited state, followed by isomerization to a transient SOO intermediate. Classical trajectories on the ground-state potential energy surface with random initial conditions qualitatively reproduce the experimental yields. This unexpected photodissociation pathway may help reconcile discrepancies in sulfur mass-independent fractionation mechanisms in Earth's geologic history, which shape our understanding of the Archean atmosphere and the Great Oxygenation Event in Earth's evolution.

Influence of Long-Term Organic Fertilization on Changes in the Content of Various Forms of Sulfur in the Soil under Maize Monoculture

Sulfur nutrition is a crucial part of proper crop growth. In this study, we investigated the influence of organic fertilizers in a long-term field experiment (23 years) with continuous maize monoculture. We focused on: (a) changes in the soil sulfur fraction pools, (b) the balance of total sulfur inputs and outputs, and (c) sulfur uptake by maize. The following treatments were selected: unfertilized control (Control), urea and ammonium nitrate (UAN), UAN and wheat straw (UAN + St), sewage sludge (SS), farmyard manure (FYM), and slurry (Slurry). Using sequential extraction, we determined water-soluble (SW—in water), adsorbed (Sads—in 0.032 mol L−1 NaH2PO4), and available (Sav = SW + Sads) sulfur content. Microwave-assisted digestion in an Aqua regia solution was used to measure the pseudo-total sulfur content (Spt). Organic-bound sulfur (Sorg) was calculated as a difference between Spt and Sav. We found that average biomass yields responded to a uniform 120 kg N ha−1 year−1 dose, rather than the dose of S in fertilizers, with an increase over the Control by 34–49%. The effect of an additional 33.5 kg N ha−1 year−1 on UAN + St treatment was not significant. Average sulfur uptake responded to increased yields (69-121% higher than Control), rather than the sulfur application, with the exception of SS, where the dose of sulfur was high enough to cause an additional uptake. In the topsoil, we discovered a significant decrease over time (from 1997 to 2019) in water-soluble (SW), adsorbed (Sads), available (Sav), and pseudo-total (Spt) fractions on all treatments to 29, 59, 37, and 82% of their initial values, respectively. For all treatments, the proportion of Sorg in Spt increased over time, which was caused by the decrease in mineral fractions (SW, Sads, Sav). The absolute content of Sorg decreased over time for all treatments except SS and FYM to about 85% of the initial value. Using the simple balancing method, we calculated that UAN + St, SS, FYM, and Slurry treatments annually lost 8.04, 66.1, 21.4, and 26.8 kg of S ha−1, respectively. This loss was attributed to the decrease in atmospheric depositions, as well as the release of sulfur from soil organic matter (for UAN + St and Slurry treatments) and a high proportion of easily mineralizable and inorganic sulfur from the SS treatment. Generally, the FYM fertilizer provided the highest potential for maintaining soil Spt status.

Continuous Large Area Monolayered Molybdenum Disulfide Growth Using Atmospheric Pressure Chemical Vapor Deposition.

The growth of large crystallite continuous monolayer materials like molybdenum disulfide (MoS2) with the desired morphology via chemical vapor deposition (CVD) remains a challenge. In CVD, the complex interplay of various factors like growth temperatures, precursors, and nature of the substrate decides the crystallinity, crystallite size, and coverage area of the grown MoS2 monolayer. In the present work, we report about the role of weight fraction of molybdenum trioxide (MoO3), sulfur, and carrier gas flow rate toward nucleation and monolayer growth. The concentration of MoO3 weight fraction has been found to govern the self-seeding process and decides the density of nucleation sites affecting the morphology and coverage area. A carrier gas flow of 100 sccm argon results in large crystallite continuous films with a lower coverage area (70%), while a flow rate of 150 sccm results in 92% coverage area with a reduced crystallite size. Through a systematic variation of experimental parameters, we have established the recipe for the growth of large crystallite atomically thin MoS2 suitable for optoelectronic devices.

Effect of Different Sources of Sulphur on Sulphur Fractions in a Calcareous Soil

An incubation experiment was conducted to study the S release pattern by different S sources and grades. The bulk soils were collected from the Esanai village which has deficient in sulphur. The treatments were replicated thrice in completely randomized design. Treatment details are Ammonium sulphate, Single Super Phosphate, Gypsum were the three sources of sulphur applied at the intervals of 0, 20, 40 kg S ha-1 along with the recommended dose of N, P and K. Destructive soil sampling was carried out at 15, 30, 60, 90 days after incubation and analyzed for S fractions as per standard procedures to understand the effect of S sources and S dynamics in those areas. Soil samples were analysed for sulphur fraction i.e. Water soluble sulphur fraction, Exchangeable sulphur fraction, CaCl2extractable sulphur fraction, Occuled sulphur fraction, Organic sulphur fraction and Total sulphur fraction. The soil sulphur fractions were arranged in the order of occluded sulphur &gt; water soluble sulphur &gt; exchangeable sulphur &gt; CaCl2 extractable sulphur &gt; organic sulphur. The results emerged out in this experiment indicate that that application of sulphur in the form of Ammonium Sulphate @ 40 kg S ha-1 was found to be applied for better release of available sulphur. The zero fertilization led to decline in the levels of all the forms of sulphur as compared to rest of treatments.

NEXAFS spectra of model sulfide chains: implications for sulfur networks obtained from inverse vulcanization.

Inverse vulcanization is a promising route to stabilize sulfur in lithium-sulfur batteries, but the resulting sulfur strand lengths in the materials are elusive. We address the strand length by characterization via sulfur near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Theoretical predictions of NEXAFS spectra for model molecules containing strands with up to three sulfur atoms are verified by experiment. The near perfect agreement between simulation and experiment on the absolute energy scale allows for the predictions for larger chain lengths also. Inspection and interpretation of NEXAFS spectra from real battery materials on this basis reveals the appearance of single connecting sulfur atoms for very low sulfur content, and of longer strands when the sulfur fraction increases.

Sulfate supplementation affects nutrient and photosynthetic status of Arabidopsis thaliana and Nicotiana tabacum differently under prolonged exposure to cadmium

Hydroponic experiments were performed to examine the effect of prolonged sulfate limitation combined with cadmium (Cd) exposure in Arabidopsis thaliana and a potential Cd hyperaccumulator, Nicotiana tabacum. Low sulfate treatments (20 and 40 µM MgSO4) and Cd stress (4 µM CdCl2) showed adverse effects on morphology, photosynthetic and biochemical parameters and the nutritional status of both species. For example, Cd stress decreased NO3- root content under 20 µM MgSO4 to approximately 50% compared with respective controls. Interestingly, changes in many measured parameters, such as chlorophyll and carotenoid contents, the concentrations of anions, nutrients and Cd, induced by low sulfate supply, Cd exposure or a combination of both factors, were species-specific. Our data showed opposing effects of Cd exposure on Ca, Fe, Mn, Cu and Zn levels in roots of the studied plants. In A. thaliana, levels of glutathione, phytochelatins and glucosinolates demonstrated their distinct involvement in response to sub-optimal growth conditions and Cd stress. In shoot, the levels of phytochelatins and glucosinolates in the organic sulfur fraction were not dependent on sulfate supply under Cd stress. Altogether, our data showed both common and species-specific features of the complex plant response to prolonged sulfate deprivation and/or Cd exposure.

Distribution of Microorganisms and Fractionation of Sulphur in Anthropogenic Wetlands under Long-term Elevated CO2 Soil

The fate of extra carbon accessing soil under elevated CO2 levels, as well as the repercussions for plant nutrition, is primarily determined by soil microbe activity. However, most increased CO2 research has reported changes usually increases in soil organic carbon and reduction in the pH of the soil which is merely the first step in understanding how soil processes are altered. We analyzed these variables by assessing enzyme activities and identifying the individual components impacted by high CO2 and those that reflect changes in soil organic matter pools. The majority of the microbial variables studied showed a significant increase under eCO2 conditions, The rise in dehydrogenase activity suggests that the increased biomass of bacteria coincided with an increase in their activity. The rise in phosphatase activities implies that organic matter breakdown is being stimulated overall. The sulphur fractions had a significantly increased number of substrates consumed by soil microorganisms under increasing CO2. Moreover, direct examination of data from these perspective steep shifts in soil biological activity points to possible areas of investigation.

Rapid Determination of Sulfur in Sixty Geological Reference Materials by High Resolution Inductively Coupled Plasma‐Mass Spectrometry

In this study, a rapid method for the quantification of sulfur mass fractions in geological materials using high‐resolution sector field‐inductively coupled plasma‐mass spectrometry (SF‐ICP‐MS) was developed. The effects of HNO3, Lefort, aqua regia, and HCl on the recoveries of sulfur in three different geological samples were evaluated. It was found that 0.5‐1 h digestion at 90 °C was enough to completely recover sulfur from BCR‐2 (basalt rock), GSS‐25 (loess), and GSD‐7 (stream sediment) using 2 ml aqua regia in both closed and open vessels. Compared with that of traditional digestion methods (e.g., HF‐HBr‐HNO3 acid digestion method), the efficiency of this proposed aqua regia digestion is improved by a factor of approximately 20. No loss of sulfur was observed because sulfur released from geological materials is directly oxidised to sulfate, which inhibits the volatilisation of sulfur. In addition, the effect of the heating‐condensing system combined with two different skimmer cones on the analytical sensitivity of sulfur was investigated. Compared with that of the normal sampling mode, the signal intensity of sulfur is enhanced by a factor of approximately 22 and 10 at a temperature of 140 °C using the S + X cone combination and S + H cone combination, respectively. This improvement is of importance for the determination of sulfur in samples with low sulfur content. The developed method was successfully applied to the determination of sulfur in geological reference materials. Most of the measured sulfur values of sixty geological materials, using both closed and open vessel digestion, are in good agreement with reference values. Compared with closed vessel digestion, the more flexible open vessel acid digestion is simple, fast, and shows great potential for the rapid quantification of sulfur in a large batch of geological and environmental samples.

Effect of Bio sulphur granules (BSG) as fertilizer ingredient on different fractions of sulphur in calcareous soil cultivated with blackgram (Var.VBN-8)

The purpose of this study was to examine the various sulphur (S) fractions in experimental pot calcareous soil treated with Bio sulphur granules (BSG) in order to assess the impact of granular sulphur fertilization in S deficient calcareous soil using blackgram (Var. VBN-8) as a test crop.Factorial randomized block design with ten treatments (T1- Absolute control;T2-Recommended dose of NPK and S (Control);T3-Soil test based NPK; T4-T3 + S as Elemental Sulphur @ 40 kg S/ha; T5-T3 + S as BSGI@ 40 kg S/ha; T6-T3 + S as BSGII@ 40 kg S/ha;T7-T3 + Vermicompost @ 4 t ha-1; T8-T4 + Vermicompost @ 4 t ha-1;T9- T5 + Vermicompost @ 4 t ha-1; T10- T6+ Vermicompost @ 4 t ha-1 ) replicated thrice and 5 pots were maintained for each replication. The results of this study revealed that there was an upward trend in all S fractions in every treatment (T1 to T10), in the following order: organic &gt; inorganic &gt; water soluble &gt; exchangeable S. The pot that received vermicompost coupled with BSG II (T10) (ES@ 40 kg ha-1 and MethylobacteriumthiocyanatumVRI7-A4 as S source) was found to have the greatest S-fraction and was higher than other treatments. Therefore, using BSG II in conjunction with vermicompost is necessary to preserve the availability of S nutrients in calcareous soil and increase the solubility of nutrients through S-oxidation.