Journal articles: 'Hydrogen sulphide – Analysis'

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Turkiewicz, Anna, Teresa Steliga, Dorota Kluk, and Zbigniew Gminski. "Biomonitoring Studies and Preventing the Formation of Biogenic H2S in the Wierzchowice Underground Gas Storage Facility." Energies 14, no. 17 (September 2, 2021): 5463. http://dx.doi.org/10.3390/en14175463.

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The article discusses the results of biomonitoring research at the Underground Gas Storage (UGS). Hydrogen sulphide, as one of the products of microbiological reaction and transformation, as well as a product of chemical reactions in rocks, is a subject of interest for global petroleum companies. The materials used in this research work were formation waters and stored natural gas. The biomonitoring of reservoir waters and cyclical analyses of the composition of gas stored at UGS Wierzchowice enabled the assessment of the microbiological condition of the reservoir environment and individual storage wells in subsequent years of operation. Investigations of the formation water from individual wells of the UGS Wierzchowice showed the presence of sulphate reducing bacteria bacteria (SRB), such as Desulfovibrio and Desulfotomaculum genera and bacteria that oxidize sulphur compounds. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide and sulphides in the reservoir waters ranged from 1.22 to 15.5 mg/dm3. The monitoring of natural gas received from UGS production wells and observation wells, which was carried out in terms of the determination of hydrogen sulphide and organic sulphur compounds, made it possible to observe changes in their content in natural gas in individual storage cycles. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide in natural gas from production wells ranged from 0.69 to 2.89 mg/dm3, and the content of organic sulphur compounds converted to elemental sulphur ranged from 0.055 to 0.130 mg Sel./Nm3. A higher hydrogen sulphide content was recorded in natural gas from observation wells in the range of 2.02–25.15 mg/Nm3. In order to explain the causes of hydrogen sulphide formation at UGS Wierzchowice, isotopic analyses were performed to determine the isotope composition of δ34SH2S, δ34SSO4, δ18OSO4 in natural gas samples (production and observation wells) and in the deep sample of reservoir water. The results of isotope tests in connection with microbiological tests, chromatographic analyses of sulphur compounds in natural gas collected from UGS Wierzchowice and an analysis of the geological structure of the Wierzchowice deposit allow us to conclude that the dominant processes responsible for the formation of hydrogen sulphide at UGS Wierzchowice are microbiological, consisting of microbial sulphate reduction (MSR). The presented tests allow for the control and maintenance of hydrogen sulphide at a low level in the natural gas received from the Wierzchowice Underground Gas Storage facility.

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Thomas, J. D. R. "Ion-selective electrode and enzyme sensors for flow-type environmental analysis." Collection of Czechoslovak Chemical Communications 56, no. 1 (1991): 178–91. http://dx.doi.org/10.1135/cccc19910178.

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Illustrative examples from researches in the author’s laboratories are given of potentiometric ion-selective electrodes (ISEs) and catalytic membrane amperometric electrodes suitable for environmental analysis. The uses of sulphide ISEs are demonstrated for monitoring the activities of sulphate-reducing bacteria, in effluent analysis for sulphide, and in process/effluent analysis for sulphide, thiols and polysulphides. Diquat and paraquat ISEs are discussed in relation to their optimisation in terms of appropriate crown ether and ion-pairing agents, together with prospects of their uses. Catalytic membrane systems for use in electrochemical analysis may be based on metal oxide catalysts or enzymes. The best of the new metal oxide catalysts for hydrogen peroxide analysis in association with an oxygen electrode is based on manganese dioxide and offers an alternative to lead dioxide and catalase. An alternative membrane system for use with a platinum electrode is peroxidase in association with a mediator in order to permit a low potential approach for hydrogen peroxide sensing. Hydrogen peroxide is a product of many oxidase catalysed reactions and its electrochemical detection permits the analysis of a wide range of substrates, illustrated here for glucose in various food products and hypoxanthine in the spoilage of fish meats.

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Xiong, Bin, Lan Peng, Xuan Cao, Yan He, and Edward S. Yeung. "Optical analysis of biological hydrogen sulphide: an overview of recent advancements." Analyst 140, no. 6 (2015): 1763–71. http://dx.doi.org/10.1039/c4an02204a.

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In this review we provide an overview of recent advancements in optical analysis of biological hydrogen sulphide, with a focus on fluorescence and non-fluorescence optical strategies for sensing and imaging subcellular hydrogen sulphide in living biosystems.

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Holder, G. A., G. Vaughan, and W. Drew. "Kinetic Studies of the Microbiological Conversion of Sulphate to Hydrogen Sulphide and their Relevance to Sulphide Generation within Sewers." Water Science and Technology 17, no. 2-3 (February 1, 1985): 183–96. http://dx.doi.org/10.2166/wst.1985.0129.

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The relevance of the studies carried out, to the important practical problem of predicting sulphide generation rates within sewers, is discussed in the introduction section of the paper. The predictive equations presently in use are compared, and the desirability of replacing these empirical equations by a more scientific approach based on an analysis of mass transport and biochemical reaction is stressed. A theoretical analysis of mass transport and metabolism of sulphate during laminar flow in a model sewer is then described. This theoretical section is followed by the description of the laboratory experimental studies. These studies consisted of flowing simulated sewage through tubes containing biofilms of mixed cultures of sulphate reducing bacteria. The results obtained in the laboratory studies showed that the diffusional resistance in the liquid phase was negligible and that the biological conversion of sulphate to sulphide followed zero order kinetics when mass transfer was not rate limiting. The observed sulphate removal rates gave good agreement with Australian field data for sulphide generation in sewers. The value of the zero order rate constant (measured at 41 °C) was 30 mg cm−3 h−1.

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Shamim, R. O., I. Dincer, and G. Naterer. "Thermodynamic analysis of solar-based photocatalytic hydrogen sulphide dissociation for hydrogen production." International Journal of Hydrogen Energy 39, no. 28 (September 2014): 15342–51. http://dx.doi.org/10.1016/j.ijhydene.2014.07.094.

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Kuliński, Włodzisław, and Barbara Zielińska. "Analysis of Physical Therapy in Psoriasis." Acta Balneologica 61, no. 2 (2019): 87–94. http://dx.doi.org/10.36740/abal201902104.

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Introduction: Psoriasis is one of the most common skin diseases. It is a chronic and recurrent disorder that constitutes both a clinical and a social problem. Psoriasis can be effectively treated with comprehensive balneophysiotherapy (sulphide/hydrogen sulphide baths, PUVA therapy, cryotherapy). Aim: To analyse physical therapy in patients with psoriasis treated at a thermal resort. Material and Methods: The study was conducted at the “Jasna” thermal resort in Solec-Zdrój. The patients underwent balneophysiotherapy in the form of sulphide/hydrogen sulphide baths, PUVA therapy, and cryotherapy. The study group consisted of 40 subjects (28 females and 12 males) with psoriasis. The mean age was 43 years (range: 21 to 65 years). Subjective (a 21-item questionnaire) and objective assessment of the patients’ status was performed both before and after a series of physical therapy procedures. Results: After 3 weeks of treatment, the patients’ physical status was remarkably improved; skin lesions, pain, and burning resolved. The mental status of the subjects was improved as well. The results confirm that physical therapy is highly effective in psoriatic patients. Conclusions: The procedures performed at the thermal resort had a beneficial influence on the subjects’ health. Remarkable improvements were found using both subjective and objective methods of assessment. Thermal hospital treatment is an optimal form of management in psoriatic patients.

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Pradhananga, Raja Ram, A. Nyachhyon, A. P. Yadav, Lok Kumar Shrestha, and S. Tandukar. "Fabrication and Applications of Silver Sulphide Based Ion Sensors." Advanced Materials Research 117 (June 2010): 7–14. http://dx.doi.org/10.4028/www.scientific.net/amr.117.7.

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An electrochemical sensor based on the silver sulphide precipitate was fabricated in the laboratory and characterized by x-ray diffraction, SEM equipped with EDAX, and electrochemical techniques. Ion selective electrode (ISE) was found to be sensitive enough to sense the sulphide ion concentration from 10-1 to 10-5 M in alkaline medium. The change in electrode potential per decade change in sulphide ion concentration was found to be 31.5 mV at laboratory temperature indicating adherence of the ion selective electrode to Nernst’s equation. The sensor have been successfully used for the quantitative determination of thiamine in pharmaceutical preparations, hydrogen sulphide in cigarette smoke and determination of solubility products of sparingly soluble silver salts. A trace amount of hydrogen sulphide, a toxic gas, is present in the cigarette smoke. The quantitative estimation of hydrogen sulphide in cigarette smoke is a challenging task to analytical chemist. Hydrogen sulphide in cigarette smoke had been determined by absorbing the cigarette smoke in 0.1 M sodium hydroxide and the resulting solution was analyzed using silver sulphide based ion sensor by standard addition technique using modified Gran plot. The average amounts of hydrogen sulphide produced by a stick of cigarette in 8 different brands of Nepalese cigarette ware found to range from 0.0332 mg to 0.0766 mg. The sensitivity and reliability of these home made ion sensors were excellent and in par with commercial electrodes. For developing countries like Nepal, who can not afford to procure high cost commercial ion selective electrodes, these home made ion sensors are especially appealing since the sensor can be fabricated with ease from the materials that are readily available in the chemistry laboratory and the sensor is quite sensitive and gives reproducible results which are sufficiently accurate for the analysis with ion selective electrodes.

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CAPEILLÈRE-BLANDIN, Chantal, Christelle MARTIN, Nicoletta GAGGERO, Piero PASTA, Giacomo CARREA, and Stefano COLONNA. "Sulphoxidation reaction catalysed by myeloperoxidase from human leucocytes." Biochemical Journal 335, no. 1 (October 1, 1998): 27–33. http://dx.doi.org/10.1042/bj3350027.

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The oxidation of alkyl aryl sulphides by myeloperoxidase (MPO) at the expense of hydrogen peroxide was investigated under steady-state conditions. The sulphide concentration effect was studied under saturating H2O2 concentrations at pH 5.0 and 20 °C. The kinetic constants, kcat and Km, of the different substrates were determined and the values were in the 1–10 s-1 range and around 43±26 µM respectively, whatever the sulphide considered. In the case of p-substituted thioanisoles, the oxidation rate was dependent upon the substituent effect. The correlation of log(kcat) with the substituent constants (δ+ values) (Hammett equation) could be explained by a reaction mechanism involving the enzyme compound II and a sulphenium radical cation. This conclusion was also supported by spectrophotometric analysis of catalytic intermediates of the enzyme, showing the accumulation of compound II. Moreover, chiral HPLC analyses showed that MPO oxidation of alkyl aryl sulphides produced the corresponding (R)-sulphoxides with a low enantioselectivity (4–8%). Chloride ion effects on the MPO-catalysed oxygenation of sulphides were also studied. Chloride acted as a substrate for MPO and as an activator in MPO-catalysed sulphoxidation. Inhibition occurred at chloride concentrations above 120 mM, whereas below 120 mM, chloride increased the reaction rate when using p-tolyl methyl sulphide as the substrate. In the presence of 100 mM chloride the catalytic efficiency (kcat/Km) of MPO increased 3–4-fold, whatever the sulphide considered, but racemic products were obtained. These data have been interpreted in the light of known structural information on the accessibility of the distal haem cavity.

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Matos, J. S., and E. R. de Sousa. "The Forecasting of Hydrogen Sulphide Gas Build-Up in Sewerage Collection Systems." Water Science and Technology 26, no. 3-4 (August 1, 1992): 915–22. http://dx.doi.org/10.2166/wst.1992.0472.

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The presence of hydrogen sulphide gas in sewerage collection systems is a common source of odour nuisance, corrosion of sewers and toxic atmospheres. The hydrogen sulphide build-up in the sewer air may be related to sulphide concentrations in the flowing sewage and with other factors, such as turbulence, aerodynamic conditions of the ventilating air now and roughness of the unsubmerged surfaces. In the present work, a mathematical model is presented for forecasting hydrogen sulphide gas build-up along gravity sewers, which is based on the analysis of a differential mass balance equation applied to a sewer reach. Good correlation was obtained, comparing the results of the model with experimental information collected in the Funchal main trunk sewer. Funchal city is the capital of Madeira, a Portuguese island in the middle of the Atlantic Ocean, and its main trunk sewer was put into operation at the beginning of 1980.

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Savelieva, V. A., A. M. Starik, N. S. Titova, and O. N. Favorskii. "Numerical Analysis of Hydrogen Sulphide Conversion to Hydrogen during Its Pyrolysis and Partial Oxidation." Combustion, Explosion, and Shock Waves 54, no. 2 (March 2018): 136–46. http://dx.doi.org/10.1134/s0010508218020028.

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11

Lipiec, Iwona, and Piotr Rusiniak. "Stability assessment of sulphur (II) compounds in medicinal water from B-8b Michał intake in Busko-Zdrój." Bulletin of Geography. Physical Geography Series 18, no. 1 (June 23, 2020): 17–23. http://dx.doi.org/10.2478/bgeo-2020-0002.

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AbstractIn this paper, the stability of sulphur (II) compounds determined as the sum of hydrogen sul-phide, hydrosulphides and sulphides was evaluated in groundwater sourced from the B-8b Michał intake. Sulphide waters are a valuable raw material used as a basis for spa treatment in Busko-Zdrój. Based on the chemical composition analyses conducted in the years 1946–2018, a general analysis of random variability and statistical analysis of data was performed using PS IMAGO 5.0.1 software. Stability assessment was carried out on the data set for the 2009–2018 period on the basis of individual measurement control charts. Trend analysis was also performed using the GWSDAT software.

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Bogusławski, Bartosz, Anna Głowacka, and Teresa Rucińska. "Microscopic Evaluation of the Manholes in Selected Sewerage Pressure System." Civil and Environmental Engineering Reports 29, no. 2 (June 1, 2019): 31–40. http://dx.doi.org/10.2478/ceer-2019-0014.

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Abstract The aim of the research was to determine changes in the elemental composition of concrete under the influence of exposure to hydrogen sulphide in the existing sewage system. The system operator pointed to significant problems with odours in this system. The research included a fragment of the pressure sewage system. The concentration of gases: hydrogen sulphide, ammonia and methane was measured in selected wells. High concentrations of hydrogen sulphide (over 200 ppm) were recorded in the studies. Concrete samples were taken from the internal walls of the well for testing. The samples were used for a microscopic analysis of their composition, using an electron microscope with an EDS attachment. Also, concrete samples from a new sewage well were tested to compare their elemental composition. Gas measurements confirmed the problem of odors, while the analysis of the elemental composition showed a significant proportion of sulphur (from 7.53% to 42.9%) on the surface of the well compared to the reference sample (0%).

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Guerrero, Lorna, Silvio Montalvo, César Huiliñir, Jose Luis Campos, Andrea Barahona, and Rafael Borja. "Advances in the biological removal of sulphides from aqueous phase in anaerobic processes: A review." Environmental Reviews 24, no. 1 (March 2016): 84–100. http://dx.doi.org/10.1139/er-2015-0046.

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In this paper, we review the latest developments in biological methods used in the removal of hydrogen sulphide, present in the liquid phase in anaerobic reactors. The toxicity of H2S to methane-forming microorganisms and the problems caused by the presence of this compound in the biogas generated during this process, as well as the main causes of hydrogen sulphide generation in anaerobic processes of wastes are also reviewed. We especially discuss the fundamentals in applying micro-aerobic conditions to remove dissolved hydrogen sulphide from the aqueous phase of an anaerobic reactor. The alternative technology of simultaneous removal of sulphide, nitrate, and organic matter is under recent investigation. Therefore, this review paper includes a study and analysis of the microbiological basis of this technology, the physical and chemical factors that influence the process and the potential application of this technology on different types of wastewaters and situations. Also considered are the fundamentals of both biofilm reactors and microbial fuel cells desulphurization. Because relatively few studies on modeling desulphurisation processes are available, we discuss the advances made in that area.

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Simonenko, Elizaveta, Vyacheslav Starkov, Ludmila Molodkina, and Alexander N. Chusov. "Experimental Modeling and Electrochemical Analysis of Salted Oily Wastewaters." Applied Mechanics and Materials 725-726 (January 2015): 1357–62. http://dx.doi.org/10.4028/www.scientific.net/amm.725-726.1357.

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The results of potentiometric titration and determination of the specific conductivity of mineralized oily wastewater from landfill areaand the results of the analysis of individual and combined model systems (bicarbonate, phosphate and hydrogen sulphide) at different volume ratios and a wide range of mineral saltsconcentrations were compared. Qualitative and quantitative characteristics of studied wastewater buffer system were defined.

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Bermejo, Emilse, Daniel Saenz, Maria Fabiana Alberto, Ruth Estela Rosenstein, and Maria Angela Lazzari. "C0270 Analysis of different mechanisms through hydrogen sulphide (H2S) inhibit platelet aggregation." Thrombosis Research 130 (October 2012): S103—S104. http://dx.doi.org/10.1016/j.thromres.2012.08.012.

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Suchorska-Woźniak, Patrycja, Olga Rac, Marta Fiedot, and Helena Teterycz. "Analysis of SnO2|WO3 Heterocontact Properties during the Detection of Hydrogen Sulphide." Sensors 14, no. 11 (October 30, 2014): 20480–99. http://dx.doi.org/10.3390/s141120480.

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Sanlı, Ayşe Elif, and Mahmut D. Mat. "Performance analysis of direct Black Sea hydrogen sulphide (in artificial sea water)/hydrogen peroxide fuel cells." International Journal of Hydrogen Energy 40, no. 19 (May 2015): 6440–48. http://dx.doi.org/10.1016/j.ijhydene.2015.03.042.

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Tran Thi Thuy, Tien, Krishnan Kannoorpatti, Anna Padovan, and Suresh Thennadil. "Effect of Alkaline Artificial Seawater Environment on the Corrosion Behaviour of Duplex Stainless Steel 2205." Applied Sciences 10, no. 15 (July 22, 2020): 5043. http://dx.doi.org/10.3390/app10155043.

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Sulphate reducing bacteria (SRB) can be found in alkaline environments. Due to their metabolite products such as hydrogen sulphide, the corrosion behaviour of materials in alkaline environments may be affected by the presence of SRB. This study focuses on the investigation of corrosion behaviour of duplex stainless steel DSS 2205 in nutrient rich artificial seawater containing SRB species, Desulfovibrio vulgaris, at different alkaline conditions with pH range from 7 to 10. The open circuit potential value (OCP), sulphide level and pH were recorded daily. Confocal laser scanning microscopy (CLSM) was used to study the adhesion of SRB on the DSS 2205 surface. Electrochemical impedance spectroscopy (EIS) was used to study the properties of the biofilm. Potentiodynamic polarization was used to study the corrosion behaviour of material. Inductively coupled plasma mass was used to measure the concentration of cations Fe, Ni, Mo, Mn in the experimental solution after 28 days. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used for surface analysis. The results showed that D. vulgaris are active in an alkaline environment with pH 7–9. However, at pH 10, D. vulgaris activity exhibited an 8-day lag. The corrosion rate of DSS 2205 at pH 9 was higher than at other pH environments due to a higher dissolved concentration of hydrogen sulphide.

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Mansurov, Z., B. Lesbayev, G. Smagulova, Zh Kulekeev, and G. Nurtaeva. "Combustion of Hydrogen Sulfide-Containing Oil on the Surface of the Water and Possible Applications of Combustion Method at Sea." Eurasian Chemico-Technological Journal 19, no. 2 (June 30, 2017): 133. http://dx.doi.org/10.18321/ectj644.

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Oil production in sea conditions is associated with certain difficulties of the field development process due to technological peculiarities of oil production at sea. The Caspian Sea is an enclosed pond with a very sensitive ecosystem, therefore, maritime operations here meet higher requirements than in open ponds. The uniqueness of the Caspian Sea is in the fact that its biological wealth has no analogues in the world, therefore, mining without complying with strict ecological requirements can cause irreparable harm to the environment. This work deals with the analysis of the possibility to use controlled combustion in situ in case of accidents on the Kashagan oil field which is located in the Caspian Sea. The Kashagan oil field is distinguished by a high content of hydrogen sulphide. In order to study the operational possibilities of oil combustion in situ, the process of evaporation and combustion of desulfurized oil from the Kashagan field depending on salinity of water was studied in this work. The process of evaporation of hydrogen sulphide from hydrogen sulphide-containing oil and the peculiarities of its combustion on water surface were studied in this work. It has been stated that the main difference in oil combustion with a high content of hydrogen sulphide is that the oil combustion process leads to the increase of sulfur concentration in oil residue after combustion.

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Elliott, R., and C. A. Pickles. "Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen." High Temperature Materials and Processes 36, no. 8 (September 26, 2017): 835–46. http://dx.doi.org/10.1515/htmp-2015-0208.

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AbstractNickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673–873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

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Tameesh, Adnan H. H., Ali O. Bender, and Takoohi M. Sarkissian. "Gas chromatographic study of the analysis and elution mechanism of hydrogen sulphide, carbonyl sulphide and light mercaptans in petroleum gases." Journal of Chromatography A 321 (January 1985): 59–67. http://dx.doi.org/10.1016/s0021-9673(01)90423-6.

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Škvareková, Erika, Marianna Tomašková, Gabriel Wittenberger, and Štefan Zelenák. "Analysis of Risk Factors for Underground Coal Gasification." Management Systems in Production Engineering 27, no. 4 (December 1, 2019): 227–35. http://dx.doi.org/10.1515/mspe-2019-0036.

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AbstractThe purpose of this article is to determine the environmental impacts of underground gasification on the population and to analyze the risk of underground coal gasification (UCG) activities using selected risk assessment methods. Coal gas is a regular part of coal deposits and its extraction also allows the use of coal deposits that cannot be extracted by traditional methods. These technologies bring both positive and negative aspects. The paper points out the risk analysis, hazard identification and assessment during the operation of UCG technology using a risk graph and a risk matrix. Identified risks to workers that cannot be reduced should be taken into consideration and appropriate safeguard should be used. For each risk, it is necessary to inform employees about regular education and training. From worldwide experience with this technology, it is possible to analyze risks in Slovakia. Actual gasification produces polluting gases such as carbon dioxide, carbon monoxide, hydrogen sulphide, hydrogen sulphide, nitrogen oxides, tar and ash, and creates a risk that may occur on and under the surface of the site depending on the geological and hydrogeological structure of the deposits. Possible measures to mitigate the adverse effects are proposed for the implementation of this technology. Coal is still one of the main domestic primary energy sources. Currently, only 5 out of 19 deposits in the Slovak Republic are used. Underground gasification could increase the use of Slovak coal and brown coal deposits.

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Grekas, N., and A. C. Calokerinos. "Molecular emission cavity analysis for organic sulphur compounds after electrolytic generation of hydrogen sulphide." Analytica Chimica Acta 202 (1987): 241–46. http://dx.doi.org/10.1016/s0003-2670(00)85921-8.

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Ruocco, G., M. Sampoli, and R. Vallauri. "Analysis of the network topology in liquid water and hydrogen sulphide by computer simulation." Journal of Chemical Physics 96, no. 8 (April 15, 1992): 6167–76. http://dx.doi.org/10.1063/1.462889.

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Eid, Letícia Palota, Renato Nery Soriano, Marcelo Eduardo Batalhão, Lais Palotta Balderrama, and Evelin Capellari Carnio. "Pharmacotherapy and analysis of gaseous mediators in hypertensive patients." Revista da Escola de Enfermagem da USP 49, no. 1 (February 2015): 69–75. http://dx.doi.org/10.1590/s0080-623420150000100009.

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OBJECTIVE To evaluate the effect of using antihypertensive classes of drugs of the calcium channel antagonists and inhibitors of angiotensin-converting enzyme in plasma concentrations of hydrogen sulfide and nitric oxide in patients with hypertension. METHODS Cross-sectional study with quantitative approach conducted with hypertensive patients in use of antihypertensive classes of drugs: angiotensin-converting enzyme inhibitors or calcium channel antagonists. RESULTS It was found that the concentration of plasma nitric oxide was significantly higher in hypertensive patients that were in use of angiotensin-converting enzyme inhibitors (p<0.03) and the hydrogen sulphide concentration was significantly higher in hypertensive plasma in use of calcium channel antagonists (p<0.002). CONCLUSION The findings suggest that these medications have as additional action mechanism the improvement of endothelial dysfunction by elevate plasma levels of vasodilatory substances.

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Schneider, Bohdan, Jindřich Hašek, and Jiří Ječný. "Crystal and molecular structure of 2-dimethylaminomethyl-3'-hydroxydiphenyl sulphide maleate." Collection of Czechoslovak Chemical Communications 55, no. 6 (1990): 1529–34. http://dx.doi.org/10.1135/cccc19901529.

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The crystal and molecular structure of the title compound, C19H21NO5S, M = 375.44, was solved by X-ray structure analysis using diffractometer intensity measurement with CuKα radiation. The space group is P1, with lattice parameters a = 555.7(3), b = 1 697.0(8), c = 1 035.4(4) pm, α = 106.77(4)°, β = 98.19(4)°, γ = 90.64(4)°, V = 923.9(8) . 106 pm3, Z = 2, ρcalc = 1.349 g/cm3, ρm = 1.32 g/cm3. Anisotropic refinement of all nonhydrogen and isotropic refinement of eight hydrogen atoms converged to R = 0.056 and wR = 0.114 for 2 481 observed reflections. Hydrogen bonds O18-H181···O25 and N9-H91···O24i join neighbouring diphenyl sulphide and maleate molecules to linear chains. The parallel chains interact through van der Waals contacts only. Molecules of maleic acid are nearly planar keeping π-electron delocalization. An angle between phenyl rings of the diphenyl sulphide molecule is 80.9(1)° and torsion angles around S-C bonds are 23.2(3)° and 73.6(3)°.

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Maasikmets, Marek, Erik Teinemaa, Allan Kaasik, and Veljo Kimmel. "Measurement and analysis of ammonia, hydrogen sulphide and odour emissions from the cattle farming in Estonia." Biosystems Engineering 139 (November 2015): 48–59. http://dx.doi.org/10.1016/j.biosystemseng.2015.08.002.

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Ianaro, Angela, Elisabetta Panza, Maria Napolitano, Paola De Cicco, Mariarosaria Bucci, Valentina Vellecco, Vincenzo Brancaleone, and Giuseppe Cirino. "P37 Pro-apoptotic effect of hydrogen sulphide in human melanoma cell lines: A signal transduction analysis." Nitric Oxide 27 (September 2012): S28—S29. http://dx.doi.org/10.1016/j.niox.2012.08.038.

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Kass, M., and A. Ivaska. "Spectrophotometric determination of sulphur dioxide and hydrogen sulphide in gas phase by sequential injection analysis technique." Analytica Chimica Acta 449, no. 1-2 (December 2001): 189–97. http://dx.doi.org/10.1016/s0003-2670(01)01364-2.

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Nasirpouri, F., H. Alizadeh, and M. Hosseingholizadeh. "Failure analysis of a carbon steel screw under the service in the presence of hydrogen sulphide." Engineering Failure Analysis 18, no. 8 (December 2011): 2316–23. http://dx.doi.org/10.1016/j.engfailanal.2011.07.001.

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Jeroschewski, Paul, and Sabine Braun. "A flow analysis system with an amperometric detector for the determination of hydrogen sulphide in waters." Fresenius' Journal of Analytical Chemistry 354, no. 2 (February 1996): 169–72. http://dx.doi.org/10.1007/pl00012724.

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Tretiach, Mauro, and Paola Ganis. "Hydrogen Sulphide and Epiphytic Lichen Vegetation: a Case Study on Mt. Amiata (Central Italy)." Lichenologist 31, no. 02 (March 1999): 163–81. http://dx.doi.org/10.1017/s0024282999000225.

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AbstractA survey aimed at studying the effects of hydrogen sulphide (H2S) on epiphytic lichen vegetation was carried out at Acquapassante (Mt. Amiata, Central Italy). In 1992, lichen vegetation was surveyed using a sampling grid often units, on 18 chestnut trees along a transect from a chimney emitting H2S to c. 200 m in the direction of the prevailing winds. A Lichen Biodiversity Index (LBI) was calculated as the sum of the frequencies of all species present within the grid. The same survey was repeated five years later. Concentration Analysis was applied to describe the data structure, and Procrustes Analysis was used to verify the congruence between the ordinations of 1992 and 1997. The statistically significant linear and non-linear regressions found between environmental variables (distance of relevés from the chimney, bark pH, lichen biomass of selected foliose and fruticose species, total sulphur content ofEvernia prunastri, Hypogymnia physodes, Parmelia sulcataandRamalina fastigiata) and the position of the relevé points on the ordination axes suggest that species distribution along the transect is related to differences in H2S tolerance. However, some crustose species (Lecanora cf. conizaeoides, L. salignaandScolkiosporum umbrinum) should be probably excluded from the computation of the LBI for monitoring purposes, as their optimum is in the immediate vicinity of the H2S source.

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Tretiach, Mauro, and Paola Ganis. "Hydrogen Sulphide and Epiphytic Lichen Vegetation: a Case Study on Mt. Amiata (Central Italy)." Lichenologist 31, no. 2 (March 1999): 163–81. http://dx.doi.org/10.1006/lich.1998.0173.

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AbstractA survey aimed at studying the effects of hydrogen sulphide (H2S) on epiphytic lichen vegetation was carried out at Acquapassante (Mt. Amiata, Central Italy). In 1992, lichen vegetation was surveyed using a sampling grid often units, on 18 chestnut trees along a transect from a chimney emitting H2S to c. 200 m in the direction of the prevailing winds. A Lichen Biodiversity Index (LBI) was calculated as the sum of the frequencies of all species present within the grid. The same survey was repeated five years later. Concentration Analysis was applied to describe the data structure, and Procrustes Analysis was used to verify the congruence between the ordinations of 1992 and 1997. The statistically significant linear and non-linear regressions found between environmental variables (distance of relevés from the chimney, bark pH, lichen biomass of selected foliose and fruticose species, total sulphur content of Evernia prunastri, Hypogymnia physodes, Parmelia sulcata and Ramalina fastigiata) and the position of the relevé points on the ordination axes suggest that species distribution along the transect is related to differences in H2S tolerance. However, some crustose species (Lecanora cf. conizaeoides, L. saligna and Scolkiosporum umbrinum) should be probably excluded from the computation of the LBI for monitoring purposes, as their optimum is in the immediate vicinity of the H2S source.

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Yessengarayev, Ye K., B. N. Surimbayev, B. S. Baimbetov, S. V. Mamyachenkov, and T. S. Kanaly. "Ore treatment hydrogen peroxide during heap leaching of gold." Kompleksnoe ispolʹzovanie mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik shikisattardy Keshendi Paidalanu 316, no. 1 (March 15, 2021): 5–14. http://dx.doi.org/10.31643/2021/6445.01.

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Over the past century, many problems have been focused on the problems of low leaching rate of gold and methods have been developed to intensify the leaching of gold. Among these methods, the use of hydrogen peroxide to accelerate the leaching of gold is known. In order to intensify the leaching process, the indicators of cyanide leaching of gold from ore using hydrogen peroxide were studied. This article presents the results of assay-gravimetric, chemical, and mineralogical analyses of gold-bearing ore from the Sari Gunay Deposit (Iran). The content of sulfide sulfur ore belongs to the category of low-sulphide, by oxidation of sulphur (50.70%) to the category of oxidized ores. Thermodynamic analysis of possible reactions of ore components with hydrogen peroxide is carried out. Laboratory studies on cyanide leaching of gold have shown that the maximum recovery of gold is 52.92% at a concentration of hydrogen peroxide of 0.5%, the recovery of gold without ore treatment is 52.03%. The results of laboratory and column tests with and without treatment with hydrogen peroxide (H2O2–0.5%) were compared. Treatment of gold-bearing ore with hydrogen peroxide during heap leaching of gold increases gold recovery by 1.2% and amounts to 55.89%, without treatment - 54.69%. This increases the consumption of sodium cyanide by 0.04 kg/t.

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Juma, Geni, Revocatus Machunda, and Tatiana Pogrebnaya. "Performance of Sweet Potato’s Leaf-Derived Activated Carbon for Hydrogen Sulphide Removal from Biogas." Journal of Energy 2020 (March 1, 2020): 1–10. http://dx.doi.org/10.1155/2020/9121085.

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In this study, sweet potato leaf activated carbon (SpLAC) was prepared by the chemical activation method using KOH and applied as an adsorbent for H2S removal from biogas. The study focused on the understanding of the effect of carbonization temperature (Tc), varying KOH : C activation ratio, flow rate (FR) of biogas, and mass of SpLAC on sample adsorption capacity. The BET analysis was performed for both fresh and spent activated carbons as well as for carbonized samples, which were not activated; also, the activated carbon was characterized by XRF and CHNS techniques. The results showed that removal efficiency (RE) of the SpLAC increased with increase carbonization temperature from 600 to 800°C and the mass of sorbent from 0.4 g to 1.0 g. The optimal test conditions were determined: 1.0 g of sorbent with a KOH : C ratio of 1 : 1, Tc=800°C, and FR=0.02 m3/h which resulted in a sorption capacity of about 3.7 g S/100 g of the SpLAC. Our findings corroborated that H2S removal was contributed not only by the adsorption process with the pore available but also by the presence of iron in the sample that reacted with H2S. Therefore, upon successful H2S sorption, SpLAC is suggested as a viable adsorbent for H2S removal from biogas.

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Znak, Z. О. "Theoretical analysis and experimental study of H2S dissociation processes in ultrahigh-frequency plasmotron." Chemistry, Technology and Application of Substances 4, no. 1 (June 1, 2021): 66–73. http://dx.doi.org/10.23939/ctas2021.01.066.

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Theoretical analysis of aerodynamic conditions in a plasma chemical reactor with tangential gas supply is carried out. It is shown that due to the creation of a swirling flow in the reactor there is a pressure gradient, due to this along the vertical axis there is a vacuum zone, which contributes to the occurrence of plasma discharge. On the basis of the carried-out experimental researches of plasmolysis of hydrogen sulphide in a swirling stream and the analysis of images of the plasma discharge with use of monochromatic light filters the general structure of the plasma discharge is established. The influence of the temperature gradient in the reactor on the possibility of the formation of sulphur clusters as a prerequisite for the formation of a high molecular weight product – polymeric sulphur – was established.

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Zaza, Fabio, Claudia Paoletti, Roberto LoPresti, Elisabetta Simonetti, and Mauro Pasquali. "Multiple regression analysis of hydrogen sulphide poisoning in molten carbonate fuel cells used for waste-to-energy conversions." International Journal of Hydrogen Energy 36, no. 13 (July 2011): 8119–25. http://dx.doi.org/10.1016/j.ijhydene.2011.01.174.

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Mulopo, Jean, and L. Schaefer. "Biological regeneration of ferric (Fe3+) solution during desulphurisation of gaseous streams: effect of nutrients and support material." Water Science and Technology 71, no. 11 (March 30, 2015): 1672–78. http://dx.doi.org/10.2166/wst.2015.144.

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This paper evaluates the biological regeneration of ferric Fe3+ solution during desulphurisation of gaseous streams. Hydrogen sulphide (H2S) is absorbed into aqueous ferric sulphate solution and oxidised to elemental sulphur, while ferric ions Fe3+ are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous iron oxidation and may probably affect the oxidation rate. In this study, the effect of nutrients and trace minerals on ferrous iron oxidation have been investigated and the results showed that the presence of nutrients and trace minerals affects the efficiency of bacterial Fe2+oxidation. The scanning electron microscopy analysis of the geotextile support material was also conducted and the results showed that the iron precipitate deposits appear to play a direct role on the bacterial biofilm formation.

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Fdz-Polanco, F., M. Fdz-Polanco, N. Fernandez, M. A. Urueña, P. A. García, and S. Villaverde. "Simultaneous organic nitrogen and sulfate removal in an anaerobic GAC fluidised bed reactor." Water Science and Technology 44, no. 4 (August 1, 2001): 15–22. http://dx.doi.org/10.2166/wst.2001.0166.

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A granular activated carbon (GAC) anaerobic fluidised bed reactor treating vinasse from an ethanol distillery of sugar beet molasses was operated for 250 days under three different organic loading rates. The reactor showed good performance in terms of organic matter removal and methane production but an anomalous behaviour in terms of unusual high concentrations of molecular nitrogen and low concentration of hydrogen sulphide in the biogas. The analysis of the different nitrogenous and sulphur compounds and the mass balances of these species in the liquid and gas phases clearly indicated an uncommon evolution of nitrogen and sulphur in the reactor. Up to 55% of the TKN and up to 80% of the sulphur disappear in the liquid phase This is the opposite to any previously reported results in the bibliography. The new postulated anaerobic process of ammonia and sulphate removal seems to follow the mechanism: SO4=+2NH4+ → S + N2 + 4H2O (ΔG° = - 47.8 kJ/mol).

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Afanasyev, A. V., A. A. Mel’nikov, S. V. Konovalov, and M. I. Vaskov. "The Analysis of the Influence of Various Factors on the Development of Stress Corrosion Defects in the Main Gas Pipeline Walls in the Conditions of the European Part of the Russian Federation." International Journal of Corrosion 2018 (June 3, 2018): 1–10. http://dx.doi.org/10.1155/2018/1258379.

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This paper considers the factors influencing the formation and development of stress corrosion defects detected during the inspection and overhaul of the main gas pipeline section. The surveyed gas pipeline is made of large diameter steel pipes made by controlled rolling, produced by various companies, with the predominance of pipes produced by the Khartsyzsk Pipe Plant (KhPP). The correlation between the geometric parameters of defects is described, which makes it possible to estimate the depth of cracks by external parameters. Mechanical tests by cyclic loading of samples containing cracks, based on the site operation data for the last 11 years, showed no crack growth in the absence of a corrosive medium. Micro-X-ray spectral analysis of metal and corrosion products showed no trace of the influence of hydrogen sulphide and nonmetallic inclusions (sulphides) on the development process of SCC. According to the results of the research, the process of development of stress corrosion on the main gas pipelines located in the European part of the Russian Federation is described. The organization operating the gas pipeline is recommended to take into consideration the results of this work during drawing up their repair plan.

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Mahato, Dibyendu, Lalita Sharma, and Rajesh Srivastava. "Study of Electron and Positron Elastic Scattering from Hydrogen Sulphide Using Analytically Obtained Static Potential." Atoms 8, no. 4 (November 18, 2020): 83. http://dx.doi.org/10.3390/atoms8040083.

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A detailed study of elastic scattering of electrons and positrons from a hydrogen sulphide (H2S) molecule is presented using the method of partial wave phase shift analysis with suitably chosen complex optical potentials. The important aspect of our present work is that we uniquely obtain static potential in an analytical form and use it along with exchange (only for electron), polarization and purely imaginary absorption potentials to define the complex optical potential. The static potential is evaluated by obtaining charge density from the H2S molecule using the molecular wavefunction represented through an accurate analytical form of the Gaussian orbitals. The primary aim of our study is to test our present approach, as applied to the electron and positron scattering from H2S. Therefore, the results for electron and positron impact differential, integral, momentum-transfer, absorption and total cross sections are obtained for the incident energies in the range of 10–500 eV. Comparisons of these different types of cross section results with the available measurements and other calculations show good agreement, which suggests the applicability of our present approach.

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E. Ibrahim, Amal, Sahar M. Awad, Shimaa M.Elshibly, and Gehan M kamal. "Biophysical study regarding the effect of hydrogen sulfide on molecular structure and DNA of mammalian cornea." International Journal of Engineering & Technology 7, no. 4 (October 6, 2018): 2789. http://dx.doi.org/10.14419/ijet.v7i4.17149.

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Background: Humans are affected by both exogenous and endogenous sources of hydrogen sulphide gas (H2S). Its health effects depend on concentration and the duration of gas exposure. These hazards include-among many effects-eye irritation, tearing and inflammation.Objectives: Our study aimed to characterize the side effects induced in cornea due to H2S exposure by using by means of comet assay and Fourior Transformer Infrared Radiation (FTIR).Materials and methods: sixty chinchilla rabbits were randomly grouped into four groups. Group one served as control. Animals were exposed to hydrogen sulphide gas with concentrations of, 90, 250 and 500 ppm. After exposure, animals were decapitated, and the eyes were enucleated from the eye globe. Their corneas were obtained by sectioning through ora serrate. Corneas were then kept frozen at – 20° C for analysis by FTIR spectral and comet assay analysisResults: NH-OH region changes revealed unusual interface/binding mechanism that related to different surrounding environment as well as co-existence of different formations and conformations in the system after exposure to H2S gas. Moreover the exposure to H2S gas has no effect on the CH stretching region that arising from lipid. All parameters of comet assay significantly increase (p˂0.05) due to exposed doses. This increase is directly proportional to the increase in exposure level.Conclusion: Hydrogen sulfide is a very toxic gas to cornea which is considered as window of the eye .it has a serious effect on molecular structure and DNA of cornea. By better understanding its toxicity, we will be able to safely make use of its various benefits without the threat of harm looming over our heads.

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Mozer, Anna. "Authigenic pyrite framboids in sedimentary facies of the Mount Wawel Formation (Eocene), King George Island, West Antarctica." Polish Polar Research 31, no. 3 (January 1, 2010): 255–72. http://dx.doi.org/10.2478/v10183-010-0004-2.

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Authigenic pyrite framboids in sedimentary facies of the Mount Wawel Formation (Eocene), King George Island, West AntarcticaPyrite framboids occur in loose blocks of plant-bearing clastic rocks related to volcano-sedimentary succession of the Mount Wawel Formation (Eocene) in the Dragon and Wanda glaciers area at Admiralty Bay, King George Island, West Antarctica. They were investigated by means of optical and scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and isotopic analysis of pyritic sulphur. The results suggest that the pyrite formed as a result of production of hydrogen sulphide by sulphate reducing bacteria in near surface sedimentary environments. Strongly negative Δ34SVCDTvalues of pyrite (-30 - -25 ‰) support its bacterial origin. Perfect shapes of framboids resulted from their growth in the open pore space of clastic sediments. The abundance of framboids at certain sedimentary levels and the lack or negligible content of euhedral pyrite suggest pulses of high supersaturation with respect to iron monosulphides. The dominance of framboids of small sizes (8-16 μm) and their homogeneous distribution at these levels point to recurrent development of a laterally continuous anoxic sulphidic zone below the sediment surface. Sedimentary environments of the Mount Wawel Formation developed on islands of the young magmatic arc in the northern Antarctic Peninsula region. They embraced stagnant and flowing water masses and swamps located in valleys, depressions, and coastal areas that were covered by dense vegetation. Extensive deposition and diagenesis of plant detritus in these environments promoted anoxic conditions in the sediments, and a supply of marine and/or volcanogenic sulphate enabled its bacterial reduction, precipitation of iron monosulphides, and their transformation to pyrite framboids.

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Mambetov, R. F., V. M. Kushnarenko, and V. S. Repyakh. "Analysis of a failure of the pipeline transporting hydrogen sulfide gas and a gas contamination control system at the pipelines of the deposits containing hydrogen sulphide." Environmental Protection in Oil and Gas Complex, no. 5 (2019): 22–26. http://dx.doi.org/10.33285/2411-7013-2019-5(290)-22-26.

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Hudák, A., M. Dudová, T. Hudáková, M. Holub, and L. Takáč. "The Level of Arsenic in Water from Mineral Water Spring Gajdovka in Košice and the Associated Health Risks." Folia Veterinaria 62, no. 2 (June 1, 2018): 73–84. http://dx.doi.org/10.2478/fv-2018-0019.

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Abstract In the recreation area Anička in Košice, there is a mineral spring that inhabitants call Gajdovka. It has been used with several breaks since the 19th century. Mineral water from this spring is specific by the presence of arsenic the concentration of which often exceeds the permitted limit level. This study focused on the analysis of the mineral composition of the spring water. Chemical and microbiological analysis was made in the years 2013—2015. In 2014, the mineral water Gajdovka was regularly monitored throughout the year with respect to the concentrations of arsenic, iron and hydrogen sulphide levels and water levels in the nearby river. The following mean concentrations were determined: total arsenic 0.063 mg.dm−3; iron 0.275 mg.dm−3; hydrogen sulfide 4.608 mg.dm−3. The concentration of iron was below the limit, while the limit for As(III) was exceeded in 2014 for 7 months. The statistical analysis showed that the season affects significantly the level of H2S and Fe and the water levels in the nearby river.

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Sánchez-Escalona, Andres Adrian, Yanán Camaraza-Medina, Yoalbys Retirado-Mediaceja, Ever Góngora-Leyva, and Manuel Vega-Almaguer. "Dimensional analysis applied to jacketed shell and tube heat exchangers modeling." Enfoque UTE 12, no. 3 (July 1, 2021): 36–50. http://dx.doi.org/10.29019/enfoqueute.745.

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Dimensional analysis was utilized on this research to establish a shortcut model for predicting hydrogen sulphide gas discharge temperature in jacketed shell and tube heat exchangers. Since the equipment belongs to an online industrial facility, the passive experimental method was applied. Selection of the heat transfer process parameters was followed by application of the Buckingham Pi-theorem and the repeating-variables technique. After formulation of the dimensionless groups, approximation of the explicit model equation was carried out through a least-squares multivariate linear regression. The model predictive ability performance was appraised by comparing predictions versus measured discharge temperatures, hence attaining a Pearson correlation of 97.5 %, a mean absolute error of 2.1 K, and 1.7 % maximum deviations. The explicit equation that was obtained is pertinent to studied heat exchangers, when 0.55 ≤ ṁ1 ≤ 0.60, 1.06 ≤ ṁ2 ≤ 1.09, and 0.22 ≤ ṁ3 ≤ 0.24 (fluids flowrate, kg/s). It can be used as an alternative calculation method for quick anticipation of the equipment performance, which overcomes computation of the overall heat transfer coefficients.

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Tománková, J., J. Bořilová, I. Steinhauserová, and L. Gallas. " Volatile organic compounds as biomarkers of the freshness of poultry meat packaged in a modified atmosphere." Czech Journal of Food Sciences 30, No. 5 (July 25, 2012): 395–403. http://dx.doi.org/10.17221/408/2011-cjfs.

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The volatile organic compounds (VOCs) in the packing of chicken meat in a modified atmosphere was qualitatively and quantitatively evaluated. The total number of 72 samples of chicken hindquarters were stored under two different modified atmospheres (70% O2, 30% CO2, and 70% argon, 30% CO2) for 20 days. Analyses were performed on Days 0, 4, 8, 12, 16, and 20. VOCs in the headspace samples were detected and quantified by gas chromatography/mass spectrometry (GC/MS) every fourth day of storage. Pentamethylheptane, dimethylsulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl tetrasulphide, hydrogen sulphide and ammonia were detected. Pentamethylheptane and ammonia had similar values for both modified atmospheres (MA). The other compounds were found only in argon MA from the Day 16 of storage with a subsequent increase of values. The measured values for dimethylsulphide were 10.7 and 13.8 mg/l, for dimethyl disulphide they were 1.9 and 10.7 mg/l, dimethyl trisulphide levels were 15.7 and 19.3 mg/l and dimethyl tetrasulphide levels were 93.2 and 418.3 mg/l for Day 16 and 20. The hydrogen sulphide level was detected from 80 to 370 mg/l after the 8th day of storage. We showed that the argon MA is less suitable for packaging raw chicken parts than the oxygen MA in view of the increased amount of microflora and unpleasant odour as assessed by sensory analysis. Oxygen prolonged the shelf life by about four days in comparison with argon. Sensory evaluation was similar for both atmospheres after air exhaustion. The argon MA did not extend the shelf life as compared to the oxygen MA.

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Govorova, Zhanna, Ekaterina Muraveva, Vadim Govorov, and Vasiliy Semenovykh. "Technology of groundwater biological deferrization." MATEC Web of Conferences 251 (2018): 03036. http://dx.doi.org/10.1051/matecconf/201825103036.

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Applicability of development of technology using bioreactor and floating media filter is shown. The technology is based on the biological oxidation of iron and manganese by a group of iron oxidizing bacteria (IOB). The description, the operating principle and the results of technology testing are given. If the content of iron is 4,9-5,71 mg/L, manganese - 0,12-0,2 mg/L and carbon dioxide and hydrogen sulphide are present, the quality of treated water meets all normative requirements. A microscopic analysis of the backwash water from bioreactor and filter was carried out. It has been established that Leptothrix type iron oxidizing bacteria are involved in the oxidation of compounds of dissolved forms of iron and manganese.

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Mannebeck, D., and H. Mannebeck. "Interlaboratory comparison of dynamic olfactometry in Central Europe 2000." Water Science and Technology 44, no. 9 (November 1, 2001): 27–32. http://dx.doi.org/10.2166/wst.2001.0501.

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This paper presents the results of an interlaboratory comparison (ringtest) on olfactometry with 31 participants from four countries in Central Europe. The aim was to give evidence of the performance of dynamic olfactometry on the basis of the European Standard prEN 13725 (Draft) “Determination of odour concentration with dynamic olfactometry”. The test included the analysis of three individual substances (n-butanol, hydrogen sulphide, tetrahydrothiophen) as well as a natural odour mixture (coffee flavour) to compare mean values and the standard deviations of results for the investigated samples. It was confirmed that laboratories working in compliance with the requirements of the new standard achieve a significantly better repeatability and reproducibility than those that are not compliant.

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Svolos, V., K. Gkikas, V. Rizou, E. Christina, P. Kapranos, J. Kleingunnewiek, J. P. Seenan, et al. "DOP02 The dose-dependent effect of enteral nutrition on faecal microbial metabolites of healthy volunteers." Journal of Crohn's and Colitis 14, Supplement_1 (January 2020): S041—S042. http://dx.doi.org/10.1093/ecco-jcc/jjz203.041.

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Abstract Background Treatment with exclusive enteral nutrition (EEN) offers a nutritional therapy paradigm in Crohn’s disease, with the extensive modulation of gut microbiome being its proposed mechanism of action (1). Recent studies propose variable clinical efficacy for 85% EN (Cheat EN/CEN), 50% EN (Partial EN/PEN) and 20% EN (maintenance EN/MEN), and a dose-dependent effect of EN use in CD (2–5). Therefore, this study aims to investigate the dose-dependent effect of 100%, 85%, 50%, and 20% EN on faecal microbial metabolites; and to investigate if this effect can be used as a compliance marker for EEN. Methods Healthy adults followed EEN, CEN, PEN or MEN diet for 7 days. Fresh faecal samples were collected before and after each dietary intervention Dietary assessment was performed throughout the intervention using estimated weight food diaries. Faecal pH, water content, Bristol Stool Chart Score, short-chain fatty acids and hydrogen sulphide were measured. Results A total of 122 faecal samples were collected from 61 subjects. The Mean(SEM) EN intake for the four groups was EEN: 100(0), CEN: 85.6(0.5), PEN: 50.1(0.4), MEN: 19.9(0.2) % of total energy intake. The baseline levels of all faecal sample measures were no different between the four groups. Faecal water content, propionic acid and Bristol Stool Chart Score significantly decreased only during EEN (all p≤0.03). Faecal pH significantly increased during EEN, CEN and PEN (all p < 0.001), but not during MEN (p = 0.728). Faecal pH post-intervention was highest for EEN, followed by CEN and PEN [Mean(SEM), EEN: 8.2(0.1); CEN: 7.8(0.2); PEN: 7.3(0.1), all pairwise p ≤ 0.002]. The faecal concentration of hydrogen sulphide, acetic and butyric acid significantly decreased following both EEN and CEN groups (all p ≤ 0.009). The concentration of acetic acid post-EEN was significantly lower than the concentration post CEN [Mean(SEM), EEN: 173(10); CEN: 261(24) μmol/g, p = 0.001]. Hydrogen sulphide and butyric acid concentrations post EEN and post CEN were unchanged (p = 0.337, p = 0.141). Conclusion EEN extensively modulates faecal microbial metabolites and CEN induces similar effects. PEN induces variable effects and further analysis should investigate if variation in responses reflects differences in the non-EN food intake of the participants (50%). MEN had no effect on faecal microbial metabolites. Further analysis including high-throughput deep sequencing techniques will provide additional information about the dose-dependent effect of EN regimen on gut microbiome composition. References 1. Quince et al., Am J Gastroenterol, 110:1718–1729. 2. Logan et al., Aliment Pharmacol Ther, 2019;50:664–674. 3. Gupta et al., IBD, 2013;19:1374–1378. 4. Duncan et al., BMC Gastroenterol, 2014;14:50. 5. Lee et al., IBD, 2015;21:1786–1793.

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Journal articles on the topic 'Hydrogen sulphide – Analysis'

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