Gaseous Sulfur Compounds Research Articles

Trifluoromethyl Fluorosulfonate (CF3OSO2F) and Trifluoromethoxy Sulfur Pentafluoride (CF3OSF5) - Two Gaseous Sulfur(VI) Compounds with Insulating Properties.

In this work, we analyzed trifluoromethyl fluorosulfonate (CF3OSO2F) and trifluoromethoxy sulfur pentafluoride (CF3OSF5) regarding their potential use as dielectrics by investigating some of their intrinsic and extrinsic properties. Both compounds show a higher breakdown voltage than SF6 with averaged relative breakdown voltages of 1.3±0.2 for CF3OSO2F and 1.4±0.2 for CF3OSF5 compared to SF6 with 1.0. Like the dielectric (CF3)2CFCN, both compounds decompose during the breakdown process. The decomposition products were analyzed by IR spectroscopy and GCIR methods. Furthermore, the molecular structures of both gaseous compounds CF3OSO2F and CF3OSF5 have been determined by in situ crystallization, and their physical properties were determined as well.

Sulfur assimilation using gaseous carbonyl sulfide by the soil fungus Trichoderma harzianum.

Fungi have the capacity to assimilate a diverse range of both inorganic and organic sulfur compounds. It has been recognized that all sulfur sources taken up by fungi are in soluble forms. In this study, we present evidence that fungi can utilize gaseous carbonyl sulfide (COS) for the assimilation of a sulfur compound. We found that the filamentous fungus Trichoderma harzianum strain THIF08, which has constitutively high COS-degrading activity, was able to grow with COS as the sole sulfur source. Cultivation with 34S-labeled COS revealed that sulfur atom from COS was incorporated into intracellular metabolites such as glutathione and ergothioneine. COS degradation by strain THIF08, in which as much of the moisture derived from the agar medium as possible was removed, indicated that gaseous COS was taken up directly into the cell. Escherichia coli transformed with a COS hydrolase (COSase) gene, which is clade D of the β-class carbonic anhydrase subfamily enzyme with high specificity for COS but low activity for CO2 hydration, showed that the COSase is involved in COS assimilation. Comparison of sulfur metabolites of strain THIF08 revealed a higher relative abundance of reduced sulfur compounds under the COS-supplemented condition than the sulfate-supplemented condition, suggesting that sulfur assimilation is more energetically efficient with COS than with sulfate because there is no redox change of sulfur. Phylogenetic analysis of the genes encoding COSase, which are distributed in a wide range of fungal taxa, suggests that the common ancestor of Ascomycota, Basidiomycota, and Mucoromycota acquired COSase at about 790-670 Ma.IMPORTANCEThe biological assimilation of gaseous CO2 and N2 involves essential processes known as carbon fixation and nitrogen fixation, respectively. In this study, we found that the fungus Trichoderma harzianum strain THIF08 can grow with gaseous carbonyl sulfide (COS), the most abundant and ubiquitous gaseous sulfur compound, as a sulfur source. When the fungus grew in these conditions, COS was assimilated into sulfur metabolites, and the key enzyme of this assimilation process is COS hydrolase (COSase), which specifically degrades COS. Moreover, the pathway was more energy efficient than the typical sulfate assimilation pathway. COSase genes are widely distributed in Ascomycota, Basidiomycota, and Mucoromycota and also occur in some Chytridiomycota, indicating that COS assimilation is widespread in fungi. Phylogenetic analysis of these genes revealed that the acquisition of COSase in filamentous fungi was estimated to have occurred at about 790-670 Ma, around the time that filamentous fungi transitioned to a terrestrial environment.

Regenerative One-Stage Catalytic Absorption Process with Cupric Ions for Removal of Reduced Sulfur Compounds in Polluted Air

Reduced volatile sulfur compounds emitted from e.g. livestock production and biogas production facilities contribute to general air pollution and local odor nuisance. Improved technologies are required to mitigate the emissions of both hydrogen sulfide and organic sulfur compounds. The present study examines the oxidative absorption of reduced sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide in a wet oxidation process with cupric chloride. It was found that this process efficiently removes both hydrogen sulfide and methanethiol with removal efficiencies >94% under all process conditions tested, while the removal of dimethyl sulfide was in the range 20-40%. The main products determined were dimethyl disulfide, dimethyl trisulfide and elemental sulfur. It was shown that the process was more efficient than the similar process with ferric ions and higher removal could be obtained with lower residence times. Furthermore, though employing cupric ion as metal catalysts results in the production of gaseous sulfur compounds, it is estimated that this process is efficient for deodorization due to the higher odor threshold values of the product compounds and the pH range is optimal for gas streams containing CO2.

Ozone Catalytic Oxidation for Gaseous Dimethyl Sulfide Removal by Using Vacuum-Ultra-Violet Lamp and Impregnated Activated Carbon

Gaseous sulfur compounds are emitted from many facilities, such as wastewater facilities or biomass power plants, due to the decay of organic compounds. Gaseous dimethyl sulfide removal by ozone catalytic oxidation was investigated in this study. A Vacuum-Ultra-Violet (VUV) xenon excimer lamp of 172 nm was used for ozone generation without NOx generation, and activated carbon impregnated with iodic acid and H2SO4 was utilized as a catalyst. Performance assessment of dimethyl sulfide removal ability was carried out by a dynamic adsorption experiment. Empty-Bed-Contact-Time (EBCT), superficial velocity, concentration of dimethyl sulfide, temperature and humidity were set at 0.48 s, 0.15 m/s, 3.0 ppm, 25 °C and 45%, respectively. Without ozone addition, the adsorption capacity of impregnated activated carbon was 0.01 kg/kg. When ozone of 7.5 ppm was added, the adsorption capacity of impregnated activated carbon was increased to 0.15 kg/kg. Methane sulfonic acid, a reaction product of dimethyl sulfide and ozone, was detected from the activated carbon. The results suggest that the VUV and activated carbon impregnated with iodic acid and H2SO4 are workable for ozone catalytic oxidation for gas treatments.

Chemical Interactions of Red Mud during the Cleaning of an Industrial Gases Ejected to the Atmosphere from Harmful Impurities

There are two serious chemical technological problems to be solved simultaneously with significant environmental and economic gain. The first problem is the necessity of complete processing of red mud. The second problem is a decrease in the amount of toxic gases ejected to the atmosphere from industrial enterprises. The importance of the solution of the first problem increased sharply after the large environmental catastrophe happened in Hungary in 2010. The risks of repeating a similar catastrophe increase because of natural cataclysms, which become more frequent. These problems can be solved by the application of multicomponent (in chemical composition) red mud, which can interact with toxic gaseous sulfur compounds and remove the latter from industrial waste gases. The results of laboratory studies are confirmed by industrial tests. The chemical and thermodynamic capacities of the material are revealed. The experimental proofs and the corresponding characteristics of the gas emissions from industrial heat and power plants and the steelmaking and agglomeration productions are presented.

Constituent transformation mechanism of concentrated leachate after incineration at different temperatures.

Spraying concentrated leachate into an incineration furnace and burning is encouraged by the Chinese government as a harmless method for leachate treatment. In this research, the constituent transformation mechanism was studied, by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDS), of residues after burning the concentrated leachate in a muffle furnace at different temperatures (750 °C, 850 °C, 900 °C, 1000 °C, and 1100 °C). XRD results showed that the main components of the residues were metal chlorides and calcium salt crystals and that the peak position of most of these crystals changed little because their crystal structure was stable at high temperatures. SEM results illustrated that the higher the burning temperature, the smaller the solid particles, and the looser the structures of the residues. EDS analysis showed that S atoms in the concentrated leachate were usually transformed into gaseous compounds during incineration, whereas most of the Cl atoms could be fastened onto solid residues if an appropriate temperature was maintained. This study concluded that 900 °C was the best burning temperature for spraying concentrated leachate into the furnace. In addition, this study suggested that material selection for the nozzle and flue gas pipelines must pay more attention to corrosion caused by gaseous sulfur compounds. Similarly, material selection for the inner wall of the incinerator furnace should pay more attention to corrosion caused by Cl atoms. This means that the municipal solid waste (MSW) incineration power plants should incorporate various and appropriate corrosion-resistant materials according to the different regions of the incinerator.

Low-Cost Colorimetric Textile Gas Sensor for Detection of Hydrogen Sulfide

Hydrogen sulfide(H2S) is a highly toxic, corrosive, flammable gas. It is produced from the microbial breakdown of organic matter in the absence of oxygen. H2S also occurs naturally in volcanic gases, hot springs, and industrially in waste water treatment, gas drilling, tanneries, etc. H2S is colorless, and it reacts with metal ions to form metal sulfides, which are insoluble. For example, lead(II) acetate, soluble white crystalline, is converted lead(II) sulfide(PbS) which is black colored insoluble solid when it exposed to H2S. Recently, there has been development in field of semiconducting metal-oxide sensors [1], optical sensors [2], electrochemical sensors [3] to real time, portable detection of H2S. This study aims to use of a cost-effective, easy to fabricate chemical textile sensor for the detection of H2S. Lead(II) acetate was chosen because of its white color crystalline and solubility. It is easy to recognize changes in color after exposure to harmful gas, H2S. Lead(II) acetate printed textile gas sensor demonstrated dark brown color upon exposure to the H2S under 1 ppm whereas no response was observed to other gas and ambient conditions. And the textile gas sensor was placed between a LED and photodiode to readout the electrical signal. Resistance of photodiode was increased with color change (H2S exposure). It can be noted that extremely small concentrations of H2S even under 1 ppm can be recognized and measured by naked eye and photodiode. This textile-based sensor is disposable, cost effective, easy to fabricate, and simple approach to detect H2S. [1] G. F. Fine et al., “Metal Oxide Semi-Conductor Gas Sensors in Environmental Monitoring,” Sensors, vol. 10, no. 6, pp. 5469–5502, Jun. 2010. [2] K. Hayashi, “Optical Chemical Sensor,” IEEJ Trans. Sensors Micromachines, vol. 135, no. 8, pp. 299–304, 2015. [3] K. E. Kramer, S. L. Rose-Pehrsson, M. H. Hammond, D. Tillett, and H. H. Streckert, “Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array,” Anal. Chim. Acta, vol. 584, no. 1, pp. 78–88, 2007. Figure 1

Ultrasound-assisted impregnation for high temperature Fischer-Tropsch catalysts

A fraction of the petroleum extracted from oil reservoirs contains associated natural gas. Rather than building infrastructure to recover low volumes of this natural gas, the industry flares or vents it to the atmosphere, which contributes to atmospheric greenhouse gas emissions but also reduces the air quality locally because it contains gaseous sulphur and nitrogen compounds. Converting the natural gas (NG) to hydrocarbons with a small-scale two-step gas-to-liquids process, is an alternative to flaring and venting. In the first step, NG reacts with oxygen to form syngas (Catalytic Partial Oxidation) and in the second step the syngas reacts over metallic catalysts to form higher paraffins at 210 °C to 300 °C—Fischer Tropsch synthesis (FT). For the first time, we synthesize bimetallic FeCo FT catalysts with ultrasound. An ultrasonic horn agitates the solution during the entire impregnation process. The active phase dispersion of the sonicated catalysts was superior to the catalyst synthesized without ultrasound, while reducing the impregnation time by a factor of three. We tested our catalysts in a lab-scale, fixed-bed reactor at 270 °C and 300 °C, and achieved 80% conversion over 3-days on stream and a 40% yield of C2+.

Desulfurization of Brown Coal in Water under Supercritical Conditions

A method for the desulfurization of brown coal by treatment in supercritical water (T = 673.15 K, P = 30 MPa) with the subsequent deposition of gaseous sulfur compounds on a copper substrate was proposed. The products were refined fuel with a low heat value of 24 MJ/kg and Cu2S films with a thickness of 0.1 mm. The semiconductor Cu2S films can be used for the preparation of thin-film photoelectric energy converters. The greatest degree of the removal of sulfur from the brown coal was observed after an hour. The main sulfur-containing gas formed upon the autoclave treatment of brown coal in supercritical water was H2S.

Methanethiol generation potential from anaerobic degradation of municipal solid waste in landfills.

Volatile sulfur compounds are the main odorants at landfills. In this study, methanethiol (CH3SH) was chosen as a typical volatile organic sulfur compound, and its generation potential was investigated during the anaerobic degradation of the organic fractions of municipal solid waste (MSW) including rice, flour food, vegetable, fish and pork, paper, cellulose textile, and yard wastes. Among the experimental wastes, gas generation was the highest in the fish and pork waste with a high CH3SH concentration of up to 2.5% (v/v). Sulfur reduction in the solid phase was mostly converted into gaseous sulfur compounds. During the whole experiment, the cumulative CH3SH generation from the fish and pork waste was 0.139Lkgdw-1, which was about 2 and 6 orders of magnitude higher than that from the other experimental wastes. The ratio of CH3SH-S to TS reduction was 31.56% in the fish and pork waste. These results would be helpful to understand the generation of volatile sulfur compounds during the anaerobic degradation of MSW and develop techniques to control odor pollution at landfills.

Metal-Organic Frameworks as a Potential Platform for Selective Treatment of Gaseous Sulfur Compounds.

The release of various anthropogenic pollutants such as gaseous sulfur compounds into the environment has been accelerated as globalization has promoted the production of high-quality products at lower prices. Because of strict enforcement of mitigation technologies, advanced materials have been developed to efficiently remove gaseous sulfur compounds released from various source processes. Metal-organic frameworks (MOFs) are promising materials to treat sulfur compounds via adsorption, catalysis, or separation. Nonetheless, the practical applicability of MOFs is limited by a number of factors including loss of structural integrity after use, limited reusability of spent MOFs, and low stability toward omnipresent molecules (e.g., H2O). Here, we provide a comprehensive assessment of MOF technology for the effective control of gaseous sulfur compounds. This review will thus help expand the fields of real-world application for MOFs with a roadmap for this highly challenging area of research.

High-Temperature Reliability of Copper Wire-Bonded Packages Encapsulated with Mold Compounds Containing Sulfur Compounds

Cu wire-bonded (CuWB) packaging is more susceptible to corrosion than traditional inert gold wires. CuWB reliability greatly depends on the compatibility of Cu wire with the surrounding encapsulating mold compound as this matrix can provide a corrosive environment leading to reliability issues. Many mold compounds contain specific components, which are sulfur-based compounds. Since the reliability testing of an encapsulated packaged device involves thermal treatments, such as the high-temperature storage life (HTSL) test, there is a concern that corrosive sulfur compounds can be produced at high temperatures (e.g., 150°C and 175°C), endangering CuWB reliability. This article describes detection methods of sulfur compounds produced from mold compounds, if any, at high temperatures such as 175°C and CuWB die package reliability with mold compounds containing sulfur compounds. The dynamic headspace concentration-gas chromatography-mass spectroscopy analysis technique was used to test liberation of gaseous and volatile sulfur compounds from mold compounds at temperatures 25°C, 150°C, 175°C, and 200°C. No gaseous sulfur compounds were detected by chromatographic methods within the time period of the experiments. To determine sulfur-containing anionic species present in the mold compound matrix, such as sulfide, sulfite, sulfate, and thiosulfate, ionic compounds were extracted to water and analyzed by ion chromatography. Upon analysis, the only sulfur-bearing anion found in the samples was sulfate. Thermally treated mold compounds for 2,000 h at 150°C and for 1,000 h at 175°C were also extracted and analyzed to determine possible decomposition of sulfur compounds due to the thermal aging process. Corrosion due to sulfur compounds and reliability of CuWB was evaluated by HTSL for 2,000 h at temperatures of 150°C and 175°C with devices packaged with mold compounds containing sulfur compounds. CuWB ball bond-Al interface and Cu stitch bond integrity were evaluated by focused ion beam-scanning electron microscopy with energy-dispersive x-ray spectroscopic analysis and wire pull and ball shear testing of CuWB ball bonds. No reliability issues due to sulfur compounds were found with mold compounds containing sulfates up to ∼45 ppm.

Removal of gaseous sulfur and phosphorus compounds by carbon-coated porous magnesium oxide composites

Carbon-coated porous magnesium oxide (MgO/C) composites were synthesized using an aerogel route for removal of dimethyl methylphosphonate (DMMP) and 2-chloroethyl ethyl sulfide (2-CEES) in dry and wet conditions. The sorption capacities of the as-prepared samples for DMMP (0.23μg/mL) and 2-CEES (0.26μg/mL) were evaluated by breakthrough experiments in nitrogen under ambient conditions. MgO/C composites exhibited a decrease in surface area with carbon content (648–723m2/g), but had a higher surface area than MgO. Under dry conditions, the sorption capacities of the MgO/C composite with a low carbon content of 6.39wt% (MgO/C-1; 67.8mg/g for DMMP and 35.3mg/g for 2-CEES) were higher than those of pure MgO and activated carbon (AC). The sorption capacity of MgO/C composites decreased with an increase in carbon content and became even lower than those of MgO and AC. Under humid conditions, the sorption capacities and breakthrough time of pure MgO decreased significantly and became lower than that of AC. In contrast, the sorption capacities of the MgO/C-1 composite for DMMP and 2-CEES under humid conditions remained at about 91 and 86% of those measured under dry conditions, and were higher than those of AC. In addition, the MgO/C composite remained reactive toward 2-CEES even under humid conditions. MgO/C composites were more stable than MgO under humid conditions because of the presence of carbon-coated shells.

Anhydrite: An important sulfur binder limiting the climatic impact of subaerial volcanic eruptions

Gaseous sulfur compounds are critical climate active volatile components released by volcanoes. Volcanic eruptions can emit massive amounts of H 2 S and SO 2 into the atmosphere, which react with oxygen and H 2 O to sulfuric acid. Formation of H 2 SO 4 aerosols, which have on a geological timescale short-term residence times of month or years, may have global climatic impact. The phase stability of sulfur-bearing minerals such as anhydrite in erupting magmas may be a key controlling factor limiting SO 2 emission during subaerial volcanic activity (Huang and Keppler, January 2015 issue of American Mineralogist ).

황화수소 정제용 아연계 분무건조 탈황제의 활성성분 함량 변경에 따른 물성 및 반응 특성

Gaseous sulfur compound such as <TEX>$H_2S$</TEX> or COS in coal- or biomass-derived hot syngas can be purified by solid sorbents at high temperatures. In this study, we investigated the physical properties and reactivity of solid regenerable desulfurization sorbents with 37.2, 41.9, and 46.5wt% ZnO to look into the ZnO content effect. The sorbents were produced by spray-drying method to apply to a fluidized-bed process. Sulfidation and regeneration reaction were carried out using a thermogravimetric analyzer. Sorbent prepared with 46.5wt% ZnO had physical properties suitable for a fluidized-bed process applications such as spherical shape, sufficient mechanical strength and density, high porosity and surface area. It showed high sulfur sorption capacity of 10.4wt% (ZnO utilization of 57%) at reaction temperatures of 500 and <TEX>$650^{\circ}C$</TEX> for sulfidation and regeneration, respectively. However, the sulfur sorption capacity and ZnO utilization were significantly reduced and dimple shape appeared when the ZnO content decreased to 37.2 and 41.9wt%. Sulfur sorption capacity and regenerability were improved as reaction temperature increased within the experimental temperatures used in this work. The reaction temperature zones of <TEX>$1500{\sim}550^{\circ}C$</TEX> and <TEX>$650{\sim}700^{\circ}C$</TEX> are recommended for sulfidation and regeneration, respectively, to lead best reaction performances of the ZnO-based spray-dried sorbents developed in this work.

High Temperature Reliability of Copper Wire - Bonded Packages Encapsulated with Mold Compounds Containing Sulfur compounds

Copper wire-bonded (CuWB) packaging is more susceptible to corrosion than traditional inert gold wires. CuWB reliability greatly depends on the compatibility of Cu wire with the surrounding encapsulating mold compound as this matrix can provide a corrosive environment leading to reliability issues. Many mold compounds contain specific components which are sulfur-based compounds. Since the reliability testing of an encapsulated packaged device involves thermal treatments such as high temperature storage life (HTSL) test, there is a concern that corrosive sulfur compounds can be produced at high temperatures, e.g. 150 °C and 175 °C, endangering CuWB reliability. This paper describes methods of detection of sulfur compounds produced from mold compounds, if any, at high temperatures such as 175 °C and CuWB die package reliability with mold compounds containing sulfur compounds. Dynamic Headspace Concentration-Gas Chromatography–Mass Spectroscopy (DHC-GC-MS) analysis technique was used to test liberation of gaseous and volatile sulfur compounds from mold compounds at temperatures 25 °C, 150 °C, 175 °C, and 200 °C. No gaseous sulfur compounds were detected by chromatographic methods within the time period of the experiments. In order to determine sulfur containing anionic species present in the mold compound matrix, such as sulfide, sulfite, sulfate and thiosulfate, ionic compounds were extracted to water and analyzed by Ion Chromatography. Upon analysis, the only sulfur bearing anion found in the samples was sulfate. Thermally treated mold compounds for 2000 hours at 150 °C and 1000 hours at 175 °C were also extracted and analyzed to determine possible decomposition of sulfur compounds due to the thermal aging process. Corrosion due to sulfur compounds and reliability of CuWB (bare Cu-25 μm wire diameter) were evaluated by HTSL for 2000 hours at temperatures of 150 °C and 175 °C with devices packaged with mold compounds containing sulfur compounds. CuWB ball bond – Al interface and Cu stitch bond integrity were evaluated by FIB (Focused Ion Beam) - SEM (Scanning Electron Microscope) with EDX (energy dispersive X-ray spectrometer) analysis and wire pull and ball shear testing of CuWB ball bonds. No reliability issues due to sulfur compounds were found with mold compounds containing sulfates up to about 45 ppm.

Direct effect of chlorine dioxide, zinc chloride and chlorhexidine solution on the gaseous volatile sulfur compounds

Objective. This study focused on the ability of aqueous anti-volatile-sulfur-compound (VSC) solutions to eliminate gaseous VSCs by direct contact in a sealed space to describe possible mode of action of anti-VSC agents. Materials and methods. Twenty milliliters of each experimental solution, 0.16% sodium chlorite, 0.25% zinc chloride, 0.1% chlorhexidine and distilled water, was injected into a Teflon bag containing mixed VSCs, hydrogen sulfide, methyl mercaptan and dimethyl sulfide and mixed vigorously for 30 s. The VSC concentration was measured by gas chromatography before, immediately after, 30 min and 60 min after mixing. Results. The sodium chlorite solution reduced the VSC concentration remarkably. After mixing, nearly all VSCs were eliminated immediately and no VSCs were detected at 30 and 60 min post-mixing. However, in the other solutions, the VSC concentration decreased by ∼30% immediately after mixing and there was no further decrease. Conclusion. The results suggest that sodium chlorite solution has the effect of eliminating gaseous VSCs directly. This must be because it can release chlorine dioxide gas which can react directly with gaseous VSCs. In the case of other solutions that have been proved to be effective to reduce halitosis clinically, it can be proposed that their anti-VSC effect is less likely due to the direct chemical elimination of gaseous VSCs in the mouth.

Sulphur cycling between terrestrial agroecosystem and atmosphere

Central gas station of the natural gas borehole system Podravina is located near the village Molve. It delivers more than a quarter of total energy used in Croatia to its consumers. Over the years, adapting technology to increasingly demanding and rigorous standards in environmental protection has become paramount. Yet, despite all the industry has undertaken to address the risk of harmful substances entering the food chain, a multidisciplinary research team of independent scientists monitors the content of specific substances in all components of the ecosystem. This paper presents measurements of total sulphur contents in soil surface [(0 to 3) cm] and subsurface [(3 to 8) cm] layers (study period: autumn 2006 - spring 2010) and in plants (study period: spring 2000 - spring 2010), and the concentration of gaseous sulphur compounds in the air. Concentrations of hydrogen sulphide (H2S) and mercaptans (RSH) were measured from the summer of 2002 until the autumn of 2010, while concentrations of sulphur dioxide (SO2) were measured from the spring of 2008 until the autumn of 2010. The paper also shows total annual atmospheric sulphur (S-SO4) deposition at Bilogora measuring station (study period: 2001 - 2010). Average monthly concentrations of H2S in air varied between 0.2 μg m-3 and 2.0 μg m-3, RSH between 0.1 μg m-3 and 24.5 μg m-3, and SO2 between 0.4 μg m-3 and 2.8 μg m-3 depending on the location and the season of sampling. Mean values of total sulphur in soil and in Plantago lanceolata plant ranged between 610 mg kg-1 and 1,599 mg kg-1 and between 3,614 mg kg-1 and 4,342 mg kg-1, respectively, depending on the soil type, location, and sampling depth. Average values of total sulphur mass ratio for all examined single soil samples (n=80) were 1,080 mg kg-1 for both studied layers, and 4,108 mg kg-1 for all analysed plant samples (n=85). Average total annual atmospheric sulphur deposition at Bilogora measuring station was 6.3 kg of S-SO4 per hectare.

Sulfur Fertilization and Fungal Infections Affect the Exchange of H2S and COS from Agricultural Crops

The emission of gaseous sulfur (S) compounds by plants is related to several factors, such as the plant S status or fungal infection. Hydrogen sulfide (H(2)S) is either released or taken up by the plant depending on the ambient air concentration and the plant demand for S. On the contrary, carbonyl sulfide (COS) is normally taken up by plants. In a greenhouse experiment, the dependence of H(2)S and COS exchange with ambient air on the S status of oilseed rape (Brassica napus L.) and on fungal infection with Sclerotinia sclerotiorum was investigated. Thiol contents were determined to understand their influence on the exchange of gaseous S compounds. The experiment revealed that H(2)S emissions were closely related to pathogen infections as well as to S nutrition. S fertilization caused a change from H(2)S consumption by S-deficient oilseed rape plants to a H(2)S release of 41 pg g(-1) (dw) min(-1) after the addition of 250 mg of S per pot. Fungal infection caused an even stronger increase of H(2)S emissions with a maximum of 1842 pg g(-1) (dw) min(-1) 2 days after infection. Healthy oilseed rape plants acted as a sink for COS. Fungal infection caused a shift from COS uptake to COS releases. The release of S-containing gases thus seems to be part of the response to fungal infection. The roles the S-containing gases may play in this response are discussed.

Identification of control parameters for the sulfur gas storability with bag sampling methods

Air samples containing sulfur compounds are often collected and stored in sample bags prior to analysis. The storage stability of six gaseous sulfur compounds (H2S, CH3SH, DMS, CS2, DMDS and SO2) was compared between two different bag materials (polyvinyl fluoride (PVF) and polyester aluminum (PEA)) at five initial concentrations (1, 10, 100, 1000, and 10,000ppb). The response factors (RF) of these samples were determined after storage periods of 0, 1, and 3days by gas chromatography–pulsed flame photometric detector (GC–PFPD) combined with an air server (AS)/thermal desorber (TD) system. Although concentration reduction occurred more rapidly from samples of the high concentration standards (1000 and 10,000ppb), such trends were not evident in their low concentration counterparts (1, 10, and 100ppb). As such, temporal changes in RF values and the associated loss rates of most sulfur gases were greatly affected by their initial concentration levels. Moreover, the storability of oxidized sulfur compound (SO2) was greatly distinguished from that of reduced sulfur compounds (RSCs), as the former almost disappeared in the PVF bag even after one day. The results of our study confirm that storability of gaseous sulfur species is affected interactively by such variables as initial gas concentration level, bag material type, and oxidation status with the associated reactivity.