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Sample records for liquid hydrogen sulfide

  1. HYDROGEN SULFIDE

    EPA Science Inventory

    This document is a review of the scientific knowledge of hydrogen sulfide in the environment. Chapter 2 contains a review of the occurrences, properties, and uses of hydrogen sulfide. In Chapter 3, the biogeochemical aspects of the sulfur cycle are discussed. Chapter 4 describes ...

  2. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    Hydrogen sulfide ; 7783 - 06 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  3. Hydrogen sulfide

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 03 / 005 www.epa.gov / iris TOXICOLOGICAL REVIEW OF HYDROGEN SULFIDE ( CAS No . 7783 - 06 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been revie

  4. Electrochemical hydrogen sulfide biosensors.

    PubMed

    Xu, Tailin; Scafa, Nikki; Xu, Li-Ping; Zhou, Shufeng; Abdullah Al-Ghanem, Khalid; Mahboob, Shahid; Fugetsu, Bunshi; Zhang, Xueji

    2016-02-01

    The measurement of sulfide, especially hydrogen sulfide, has held the attention of the analytical community due to its unique physiological and pathophysiological roles in biological systems. Electrochemical detection offers a rapid, highly sensitive, affordable, simple, and real-time technique to measure hydrogen sulfide concentration, which has been a well-documented and reliable method. This review details up-to-date research on the electrochemical detection of hydrogen sulfide (ion selective electrodes, polarographic hydrogen sulfide sensors, etc.) in biological samples for potential therapeutic use. PMID:26806283

  5. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K. C. Kwon

    2007-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 130-156 seconds at 120-140 C to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases, evaluate removal capabilities of hydrogen sulfide and COS from coal gases with formulated catalysts, and develop an economic regeneration method of deactivated catalysts. Simulated coal gas mixtures consist of 3,300-3,800-ppmv hydrogen sulfide, 1,600-1,900 ppmv sulfur dioxide, 18-21 v% hydrogen, 29-34 v% CO, 8-10 v% CO{sub 2}, 5-18 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 114-132 SCCM. The temperature of the reactor is controlled in an oven at 120-140 C. The pressure of the reactor is maintained at 116-129 psia. The molar ratio of H{sub 2}S to SO{sub 2} in the monolithic catalyst reactor is maintained approximately at 2 for all the reaction experiment runs.

  6. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K.C. Kwon

    2009-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash coat, and catalytic metals, to develop a regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor. The task of developing kinetic rate equations and modeling the direct oxidation process to assist in the design of large-scale plants will be abandoned since formulation of catalysts suitable for the removal of H{sub 2}S and COS is being in progress. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. Experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 46-570 seconds under reaction conditions to formulate catalysts suitable for the removal of H{sub 2}S and COS from coal gases and evaluate their capabilities in reducing hydrogen sulfide and COS in coal gases. Simulated coal gas mixtures consist of 3,200-4,000-ppmv hydrogen sulfide, 1,600-20,000-ppmv sulfur dioxide, 18-27 v% hydrogen, 29-41 v% CO, 8-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of simulated coal gas mixtures to the reactor are 30 - 180 cm{sup 3}/min at 1 atm and 25 C (SCCM). The temperature of the reactor is controlled in an oven at 120-155 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio of H{sub 2}S to SO{sub 2} in the monolithic catalyst reactor is maintained approximately at 2 for all the reaction experiment runs.

  7. Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

    SciTech Connect

    K. C. Kwon

    2006-09-30

    Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2} in coal gas is directly oxidized to elemental sulfur over a selective catalyst. Such a process is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S In the Single-Step Sulfur Recovery Process (SSRP), the direct oxidation of H{sub 2}S to elemental sulfur in the presence of SO{sub 2} is ideally suited for coal gas from commercial gasifiers with a quench system to remove essentially all the trace contaminants except H{sub 2}S. This direct oxidation process has the potential to produce a super clean coal gas more economically than both conventional amine-based processes and HGD/DSRP. The H{sub 2} and CO components of syngas appear to behave as inert with respect to sulfur formed at the SSRP conditions. One problem in the SSRP process that needs to be eliminated or minimized is COS formation that may occur due to reaction of CO with sulfur formed from the Claus reaction. The objectives of this research are to formulate monolithic catalysts for removal of H{sub 2}S from coal gases and minimum formation of COS with monolithic catalyst supports, {gamma}-alumina wash or carbon coats, and catalytic metals, to develop a catalytic regeneration method for a deactivated monolithic catalyst, to measure kinetics of both direct oxidation of H{sub 2}S to elemental sulfur with SO{sub 2} as an oxidizer and formation of COS in the presence of a simulated coal gas mixture containing H{sub 2}, CO, CO{sub 2}, and moisture, using a monolithic catalyst reactor, and to develop kinetic rate equations and model the direct oxidation process to assist in the design of large-scale plants. This heterogeneous catalytic reaction has gaseous reactants such as H{sub 2}S and SO{sub 2}. However, this heterogeneous catalytic reaction has heterogeneous products such as liquid elemental sulfur and steam. To achieve the above-mentioned objectives using a monolithic catalyst reactor, experiments on conversion of hydrogen sulfide into elemental sulfur and formation of COS were carried out for the space time range of 40-560 seconds at 120-150 C to evaluate effects of reaction temperatures, total pressure, space time, and catalyst regeneration on conversion of hydrogen sulfide into elemental sulfur and formation of COS. Simulated coal gas mixtures consist of 3,600-4,000-ppmv hydrogen sulfide, 1,800-2,000 ppmv sulfur dioxide, 23-27 v% hydrogen, 36-41 v% CO, 10-12 v% CO{sub 2}, 0-10 vol % moisture, and nitrogen as remainder. Volumetric feed rates of a simulated coal gas mixture to the reactor are 30-180 SCCM. The temperature of the reactor is controlled in an oven at 120-150 C. The pressure of the reactor is maintained at 40-210 psia. The molar ratio of H{sub 2}S to SO{sub 2} in the monolithic catalyst reactor is maintained approximately at 2 for all the reaction experiment runs.

  8. Suicide with hydrogen sulfide.

    PubMed

    Sams, Ralph Newton; Carver, H Wayne; Catanese, Charles; Gilson, Thomas

    2013-06-01

    This presentation will address the recent rise of suicide deaths resulting from the asphyxiation by hydrogen sulfide (H2S) gas.Hydrogen sulfide poisoning has been an infrequently encountered cause of death in medical examiner practice. Most H2S deaths that have been reported occurred in association with industrial exposure.More recently, H2S has been seen in the commission of suicide, particularly in Japan. Scattered reports of this phenomenon have also appeared in the United States.We have recently observed 2 intentional asphyxial deaths in association with H2S. In both cases, the decedents committed suicide in their automobiles. They generated H2S by combining a sulfide-containing tree spray with toilet bowl cleaner (with an active ingredient of hydrogen chloride acid). Both death scenes prompted hazardous materials team responses because of notes attached to the victims' car windows indicating the presence of toxic gas. Autopsy findings included discoloration of lividity and an accentuation of the gray matter of the brain. Toxicology testing confirmed H2S exposure with the demonstration of high levels of thiosulfate in blood.In summary, suicide with H2S appears to be increasing in the United States. PMID:23574866

  9. A liquid crystal-based passive badge for personal monitoring of exposure to hydrogen sulfide.

    PubMed

    Robinson, Sheila E; Grinwald, Bart A; Bremer, Laura L; Kupcho, Kurt A; Acharya, Bharat R; Owens, Patrick D

    2014-01-01

    A new liquid crystal (LC)-based passive dosimeter badge for personal monitoring of exposure to hydrogen sulfide (H2S) gas is reported. When a thin film of LC supported on a surface functionalized with lead perchlorate Pb(ClO4)2 (the LC sensor) is exposed to H2S, the orientation of LC molecules in the film changes from perpendicular to parallel. This reorientation induces a change in the appearance of the LC film when viewed between crossed polarizers. A H2S dosimeter was fabricated by pairing a LC sensor with a glass substrate forming a headspace between the two surfaces, to control diffusion of H2S across the LC film. When the dosimeter is exposed to H2S, a bright front appears as a function of exposure time. An algorithm has been developed to correlate this response length and exposure dose. The dosimeters are functionally stable when subjected to extreme temperature and humidity fluctuations, and are immune to a number of potentially interfering chemicals, except mercaptans. These dosimeters detect H2S at 0.2 ppm TWA (8 hr) with 20% overall accuracy. The dosimeters were used to monitor the personal exposure of personnel working in an oil refinery. The TWA concentrations measured by the LC-based dosimeters correlate strongly with the NIOSH 1063 method that uses a sorbent tube and a pump followed by laboratory analysis. Thus, the LC-based dosimeters can provide a sensitive tool for on-site assessment of personal exposure to H2S in different environments. PMID:24766440

  10. Nonaqueous System of Iron-Based Ionic Liquid and DMF for the Oxidation of Hydrogen Sulfide and Regeneration by Electrolysis.

    PubMed

    Guo, Zhihui; Zhang, Tingting; Liu, Tiantian; Du, Jun; Jia, Bing; Gao, Shujing; Yu, Jiang

    2015-05-01

    To improve the hydrogen sulfide removal efficiency with the application of an iron-based imidazolium chloride ionic liquid (Fe(III)-IL) as desulfurizer, Fe(II) and N,N-dimethylformamide (DMF) are introduced to Fe(III)-IL to construct a new nonaqueous desulfurization system (Fe(III/II)-IL/DMF). Following desulfurization, the system can be regenerated using the controlled-potential electrolysis method. The addition of Fe(II) in Fe(III)-IL is beneficial for the hydrogen sulfide removal and the electrochemical regeneration of the desulfurizer. The addition of DMF in Fe(III/II)-IL does not change the structure of Fe(III/II)-IL but clearly decreases the acidity, increases the electrolytic current, and decreases the stability of the Fe-Cl bond in Fe(III/II)-IL. Fe(III/II)-IL/DMF can remove hydrogen sulfide and can be regenerated through an electrochemical method more efficiently than can Fe(III/II)-IL. After six cycles, the desulfurization efficiency remains higher than 98%, and the average conversion rate of Fe(II) is essentially unchanged. No sulfur peroxidation occurs, and the system remains stable. Therefore, this new nonaqueous system has considerable potential for removing H2S in pollution control applications. PMID:25822982

  11. Hydrogen sulfide intoxication.

    PubMed

    Guidotti, Tee L

    2015-01-01

    Hydrogen sulfide (H2S) is a hazard primarily in the oil and gas industry, agriculture, sewage and animal waste handling, construction (asphalt operations and disturbing marshy terrain), and other settings where organic material decomposes under reducing conditions, and in geothermal operations. It is an insoluble gas, heavier than air, with a very low odor threshold and high toxicity, driven by concentration more than duration of exposure. Toxicity presents in a unique, reliable, and characteristic toxidrome consisting, in ascending order of exposure, of mucosal irritation, especially of the eye ("gas eye"), olfactory paralysis (not to be confused with olfactory fatigue), sudden but reversible loss of consciousness ("knockdown"), pulmonary edema (with an unusually favorable prognosis), and death (probably with apnea contributing). The risk of chronic neurcognitive changes is controversial, with the best evidence at high exposure levels and after knockdowns, which are frequently accompanied by head injury or oxygen deprivation. Treatment cannot be initiated promptly in the prehospital phase, and currently rests primarily on supportive care, hyperbaric oxygen, and nitrite administration. The mechanism of action for sublethal neurotoxicity and knockdown is clearly not inhibition of cytochrome oxidase c, as generally assumed, although this may play a role in overwhelming exposures. High levels of endogenous sulfide are found in the brain, presumably relating to the function of hydrogen sulfide as a gaseous neurotransmitter and immunomodulator. Prevention requires control of exposure and rigorous training to stop doomed rescue attempts attempted without self-contained breathing apparatus, especially in confined spaces, and in sudden release in the oil and gas sector, which result in multiple avoidable deaths. PMID:26563786

  12. Modeling hydrogen sulfide emissions across the gas-liquid interface of an anaerobic swine waste treatment storage system

    NASA Astrophysics Data System (ADS)

    Blunden, Jessica; Aneja, Viney P.; Overton, John H.

    Hydrogen sulfide (H 2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive "rotten egg" smell and is considered a toxic manure gas. In the southeastern United States, anaerobic waste treatment lagoons are widely used to store and treat hog excreta at commercial hog farms. Hydrogen sulfide is produced as manure decomposes anaerobically, resulting from the mineralization of organic sulfur compounds as well as the reduction of oxidized inorganic sulfur compounds by sulfur-reducing bacteria. The process of H 2S emissions from anaerobic waste treatment lagoons are investigated utilizing a two-film model with three different modeling approaches: Coupled Mass Transfer with Chemical Reactions Model with the assumption (1) pH remains constant in the liquid film (MTCR Model I) and (2) pH may change throughout the liquid film due to diffusion processes that occur within the film (MTCR Model II); and (3) a Mass Transfer Model which neglects chemical reactions (MTNCR Model) in the gas and liquid films. Results of model predictions are consistent with previous works, which show that flux is largely dependent on the physicochemical lagoon properties including sulfide concentration, pH, and lagoon temperature. Air temperature and low wind velocities (e.g., <3.25 m s -1) have negligible impact on flux. Results also indicate that flux values decrease with increased film thickness. The flux was primarily influenced by variations in the liquid film thickness, signifying that the H 2S flux is driven by liquid-phase parameters. Model results were compared with H 2S flux measurements made at a swine waste treatment storage lagoon in North Carolina using a dynamic emission flux chamber system in order to evaluate model accuracy in calculating lagoon H 2S emissions. The MTCR Model II predicted the highest increase in emission rates as aqueous sulfide concentration was increased. The MTNCR Model showed the highest dependence on pH. All three models showed good agreement in diurnal comparison with flux measurements; however, each model significantly over predicted the measured flux rates. The MTNCR Model estimates were closest to experimental values, predicting 3-35 times the actual measured values.

  13. Study and modeling of the evolution of gas-liquid partitioning of hydrogen sulfide in model solutions simulating winemaking fermentations.

    PubMed

    Mouret, Jean-Roch; Sablayrolles, Jean-Marie; Farines, Vincent

    2015-04-01

    The knowledge of gas-liquid partitioning of aroma compounds during winemaking fermentation could allow optimization of fermentation management, maximizing concentrations of positive markers of aroma and minimizing formation of molecules, such as hydrogen sulfide (H2S), responsible for defects. In this study, the effect of the main fermentation parameters on the gas-liquid partition coefficients (Ki) of H2S was assessed. The Ki for this highly volatile sulfur compound was measured in water by an original semistatic method developed in this work for the determination of gas-liquid partitioning. This novel method was validated and then used to determine the Ki of H2S in synthetic media simulating must, fermenting musts at various steps of the fermentation process, and wine. Ki values were found to be mainly dependent on the temperature but also varied with the composition of the medium, especially with the glucose concentration. Finally, a model was developed to quantify the gas-liquid partitioning of H2S in synthetic media simulating must to wine. This model allowed a very accurate prediction of the partition coefficient of H2S: the difference between observed and predicted values never exceeded 4%. PMID:25763810

  14. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.490 Section 250.490... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide....

  15. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  16. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.604 Section 250.604...-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined...

  17. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  18. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL... § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or...

  19. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  20. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  1. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  2. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOEpatents

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  3. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  4. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  5. 30 CFR 250.604 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Hydrogen sulfide. 250.604 Section 250.604... § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of H2S is unknown (as defined in § 250.490 of...

  6. 30 CFR 250.808 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Hydrogen sulfide. 250.808 Section 250.808 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE... Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain...

  7. Ammonia and hydrogen sulfide removal using biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  8. Hydrogen sulfide pollution in wastewater treatment facilities

    SciTech Connect

    AlDhowalia, K.H. )

    1987-01-01

    The hydrogen sulfide (H{sub 2}S) found in wastewater collection systems and wastewater treatment facilities results from the bacterial reduction of the sulfate ion (SO{sub 4}). Hydrogen sulfide is a gas that occurs both in the sewer atmosphere and as a dissolved gas in the wastewater. When raw wastewater first enters the wastewater treatment facility by gravity most of the hydrogen sulfide is in the gaseous phase and will escape into the atmosphere at the inlet structures. Also some of the dissolved hydrogen sulfide will be released at points of turbulance such as at drops in flow, flumes, or aeration chambers. Several factors can cause excessive hydrogen sulfide concentrations in a sewerage system. These include septic sewage, long flow times in the sewerage system, high temperatures, flat sewer grades, and poor ventilation. These factors are discussed in this paper.

  9. Suicide by hydrogen sulfide inhalation.

    PubMed

    Bott, Eleanor; Dodd, Malcolm

    2013-03-01

    The authors report a case of suicide by hydrogen sulfide in Australia. A young woman was located in a car wearing protective eyewear. A tub of foamy yellow substance and a quantity of hydrochloric acid and lime sulfur were also located in the rear of the vehicle. Morphological findings at autopsy were nonspecific. Toxicologic analysis of a specimen of leg blood detected elevated levels of methemoglobin. If Australia follows a similar trend to Japan and the United States, it is possible that incidences of such cases will rise, probably because of Internet dissemination. From a public health perspective, emergency service providers and forensic case workers should be aware of the potential hazards to themselves and others when dealing with such cases. PMID:23361075

  10. Health effects of hydrogen sulfide

    SciTech Connect

    Tatum, V.L.

    1996-12-31

    Hydrogen sulfide is a product of a number of natural processes, such as bacterial decomposition of organic matter and geothermal activity. It is a component of crude petroleum, natural gas and volcanic gases. Although high concentrations of H{sub 2}S are acutely toxic, exposure to low concentrations is not generally associated with adverse health effects. Epidemiological studies overall have not demonstrated significant health effects or increased risk of cancer among workers or residents exposed to low levels of H{sub 2}S and other reduced sulfur gases, and based on known mechanisms of H{sub 2}S toxicity, any such effects are unlikely. However, some individuals have associated minor, subjective-type physical symptoms with exposure to low levels of reduced sulfur gases. The potential mechanism(s) for, or significance of, these responses is not well understood.

  11. An analysis on the BIOX process to hydrogen sulfide abatement

    SciTech Connect

    Nardini, G.; Paglianti, A.; Petarca, L.

    1995-12-31

    Few years ago a new method to solve the problem of hydrogen sulfide emission from geothermal plants has been developed. This method is based on the liquid phase oxidation of the hydrogen sulfide, that is carried out in the cooling tower using an oxidizing biocide as catalyst. This process called {open_quotes}BIOX{close_quotes} (BIocide-assisted OXidation) has been developed by Darrell L. Gallup that suggests to use Trichloroisocyanuric acid as oxidizing biocide. According to this author, using this agent it is possible to reduce secondary emission of hydrogen sulfide from cooling tower and if the lay out of the plant is modified, sending the turbine offgases to the liquid loop of the cooling tower, it is also possible to prevent primary emission. In this work an analysis of the process has been developed to verify the limits of the process.

  12. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1993-05-18

    A process is described for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is [dis]associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  13. Hydrogen and sulfur recovery from hydrogen sulfide wastes

    DOEpatents

    Harkness, John B. L.; Gorski, Anthony J.; Daniels, Edward J.

    1993-01-01

    A process for generating hydrogen and elemental sulfur from hydrogen sulfide waste in which the hydrogen sulfide is associated under plasma conditions and a portion of the hydrogen output is used in a catalytic reduction unit to convert sulfur-containing impurities to hydrogen sulfide for recycle, the process also including the addition of an ionizing gas such as argon to initiate the plasma reaction at lower energy, a preheater for the input to the reactor and an internal adjustable choke in the reactor for enhanced coupling with the microwave energy input.

  14. Ridding Groundwater of Hydrogen Sulfide. Part 1.

    ERIC Educational Resources Information Center

    Lochrane, Thomas G.

    1979-01-01

    This article is the first in a series reviewing the problems associated with hydrogen sulfide in drinking water sources. Discussion centers on identification of a cost-effective balance between aeration and chlorination treatment operations. (AS)

  15. Infrared spectroscopy of solid hydrogen sulfide and deuterium sulfide.

    PubMed

    Fathe, Kristin; Holt, Jennifer S; Oxley, Susan P; Pursell, Christopher J

    2006-09-21

    The infrared spectra of solid hydrogen sulfide (H2S) and deuterium sulfide (D2S) were collected at very low temperatures. Vapor deposition of thin films at the lowest temperature of 10 K produced amorphous solids while deposition at 70 K yielded the crystalline phase III. Infrared interference fringe patterns produced by the films during deposition were used to determine the film thickness. Careful measurement of the integrated absorbance peaks, along with the film thickness, allowed determination of the integrated band intensities. This report represents the first complete presentation of the infrared spectra of the amorphous solids. Observations of peaks near 3.915 and 1.982 microm (ca. 2554 and 5045 cm(-1), respectively) may be helpful in the conclusive identification of solid hydrogen sulfide on the surface of Io, a moon of Jupiter. PMID:16970373

  16. Interactions of hydrogen sulfide with myeloperoxidase

    PubMed Central

    Plinks, Zoltn; Furtmller, Paul G; Nagy, Attila; Jakopitsch, Christa; Pirker, Katharina F; Magierowski, Marcin; Jasnos, Katarzyna; Wallace, John L; Obinger, Christian; Nagy, Pter

    2015-01-01

    Background and Purpose The actions of hydrogen sulfide in human physiology have been extensively studied and, although it is an essential mediator of many biological functions, the underlying molecular mechanisms of its actions are ill-defined. To elucidate the roles of sulfide in inflammation, we have investigated its interactions with human myeloperoxidase (MPO), a major contributor to inflammatory oxidative stress. Experimental Approach The interactions of sulfide and MPO were investigated using electron paramagnetic resonance, electronic circular dichroism, UV-vis and stopped-flow spectroscopies. Key Results We found favourable reactions between sulfide and the native-ferric enzyme as well as the MPO redox intermediates, ferrous MPO, compound I and compound II. Sulfide was a potent reversible inhibitor of MPO enzymic activity with an IC50 of 1?M. In addition, the measured second-order rate constants for the reactions of sulfide with compound I [k = (1.1 0.06) 106?M?1?s?1] and compound II [k = (2.0 0.03) 105?M?1?s?1] suggest that sulfide is a potential substrate for MPO?in vivo. Conclusion and Implications Endogenous levels of sulfide are likely to inhibit the activity of circulating and endothelium-bound MPO. The fully reversible inhibition suggests a mediatory role of sulfide on the oxidant-producing function of the enzyme. Furthermore, the efficient HOCl oxidation of sulfide to give polysulfides (recently recognized as important components of sulfide biology) together with MPO-catalysed sulfide oxidation and the lack of interaction between MPO and sulfide oxidation products, predict a modulatory role of MPO in sulfide signalling. Linked Articles This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6 PMID:24824874

  17. Photocatalytic properties of colloidal metal sulfides in the decomposition of hydrogen sulfide in aqueous solutions

    SciTech Connect

    Gruzdkov, Yu.A.; Savinov, E.N.; Parmon, V.N.

    1987-03-01

    Investigation has been made of the possibility of using certain metallic sulfides as photocatalysts of the decomposition of hydrogen sulfide into hydrogen and sulfur. It has been shown that photocatalytic activity is possessed by the semiconducting sulfides with the widest forbidden bands. A method is proposed for protecting a photocatalyst from deactivation by the use of an intermediate oxidizer of hydrogen sulfide.

  18. Micro-aeration for hydrogen sulfide removal from biogas

    NASA Astrophysics Data System (ADS)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration was affected by changes in liquid heights the most, followed by changes in flow rates. Feasibility studies for H2S removal from biogas by micro-aeration were conducted at the Ames Water Pollution Control Facility (AWPCF) by using different types of liquid media available at the plant, i.e. plant effluent, mixed liquor, and digester supernatant. From the experiment at AWPCF, it was found that operating pHs were affected by the amount of alkalinity in the liquid media and that the removal efficiencies were affected by the operating pH. Among all the liquid media tested, digester supernatant showed the greatest potential with more than 99% H2S removal at an operating pH of 7.0 and volumetric biogas flow rate of 21.6 m3/m 3-hr. By increasing trace metal contents and temperature of the medium, the hydrogen sulfide removal rate was greatly improved. The operating cost of the full-scale system was estimated to be approximately $2/kg-S-removed. In addition, it was also revealed that abiotic sulfide oxidation accounted for 95% of overall sulfide oxidation. This technology is expected to widen the use of biogas as a renewable fuel since the maintenance requirements of biogas handling equipment, the methane purification costs, and the emissions of SOx will dramatically be reduced. Importantly, the technology does not require inoculation of special bacteria, addition of nutrients and trace elements, or chemicals for pH control.

  19. Hydrogen sulfide and translational medicine

    PubMed Central

    Guo, Wei; Cheng, Ze-yu; Zhu, Yi-zhun

    2013-01-01

    Hydrogen sulfide (H2S) along with carbon monoxide and nitric oxide is an important signaling molecule that has undergone large numbers of fundamental investigations. H2S is involved in various physiological activities associated with the regulation of homeostasis, vascular contractility, pro- and anti-inflammatory activities, as well as pro- and anti-apoptotic activities etc. However, the actions of H2S are influenced by its concentration, reaction time, and cell/disease types. Therefore, H2S is a signaling molecule without definite effect. The use of existing H2S donors is limited because of the instant release and short lifetime of H2S. Thus, translational medicine involving the sustained and controlled release of H2S is of great value for both scientific and clinical uses. H2S donation can be manipulated by different ways, including where H2S is given, how H2S is donated, or the specific structures of H2S-releasing drugs and H2S donor molecules. This review briefly summarizes recent progress in research on the physiological and pathological functions of H2S and H2S-releasing drugs, and suggests hope for future investigations. PMID:24096643

  20. Hydrogen Sulfide as a Gasotransmitter

    PubMed Central

    Gadalla, Moataz M.; Snyder, Solomon H.

    2010-01-01

    Nitric oxide (NO) and carbon monoxide (CO) are well established as messenger molecules throughout the body, gasotransmitters, based on striking alterations in mice lacking the appropriate biosynthetic enzymes. Hydrogen sulfide (H2S) is even more chemically reactive, but till recently there was little definitive evidence for its physiologic formation. Cystathionine ?-synthase (CBS, EC 4.2.1.22), and Cystathionine ?-lyase (CSE; EC 4.4.1.1), also known as cytathionase, can generate H2S from cyst(e)ine. Very recent studies with mice lacking these enzymes have established that CSE is responsible for H2S formation in the periphery, while in the brain CBS is the biosynthetic enzyme. Endothelial-derived relaxing factor (EDRF) activity is reduced 80% in the mesenteric artery of mice with deletion of CSE, establishing H2S as a major physiologic EDRF. H2S appears to signal predominantly by S-sulfhydrating cysteines in its target proteins, analogous to S-nitrosylation by NO. Whereas S-nitrosylation typically inhibits enzymes, S-sulfhydration activates them. S-nitrosylation basally affects 12% of its target proteins, while 1025% of H2S target proteins are S-sulfhydrated. In summary, H2S appears to be a physiologic gasotransmitter of comparable importance to NO and CO. PMID:20067586

  1. Hydrogen Sulfide Inhibits Amyloid Formation

    PubMed Central

    2015-01-01

    Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer’s disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL). HEWL forms typical β-sheet rich fibrils during the course of 70 min at low pH and high temperatures. The addition of H2S completely inhibits the formation of β-sheet and amyloid fibrils, as revealed by deep UV resonance Raman (DUVRR) spectroscopy and ThT fluorescence. Nonresonance Raman spectroscopy shows that disulfide bonds undergo significant rearrangements in the presence of H2S. Raman bands corresponding to disulfide (RSSR) vibrational modes in the 550–500 cm–1 spectral range decrease in intensity and are accompanied by the appearance of a new 490 cm–1 band assigned to the trisulfide group (RSSSR) based on the comparison with model compounds. The formation of RSSSR was proven further using a reaction with TCEP reduction agent and LC-MS analysis of the products. Intrinsic tryptophan fluorescence study shows a strong denaturation of HEWL containing trisulfide bonds. The presented evidence indicates that H2S causes the formation of trisulfide bridges, which destabilizes HEWL structure, preventing protein fibrillation. As a result, small spherical aggregates of unordered protein form, which exhibit no cytotoxicity by contrast with HEWL fibrils. PMID:25545790

  2. Microwave plasma dissociation of hydrogen sulfide

    SciTech Connect

    Harkness, J.B.L.; Gorski, A.J.; Daniels, E.J.

    1988-01-01

    The Claus technology and its associated tail gas cleanup (SCOT unit) for hydrogen sulfide environmental control recovers the sulfur contained in hydrogen sulfide wastes but loses the hydrogen as water. The alternative treatment process proposed in this paper uses plasma dissociation to recover the hydrogen in addition to the sulfur, thereby saving a significant fraction of the lost energy. The plasma process also appears to be more economical than the Claus/SCOT process. The total capital required for the plasma facility is projected to be $14 million, versus $26 million (including capital cost for the incremental hydrogen generation capacity) for the Calus/SCOT process. Because of energy savings, the annual operating costs for the plasma process are also lower than for the Claus/SCOT process. Assuming a 15% rate of return on capital, the plasma process will produce a net annual profit of $1.8 million relative to the Claus/SCOT. 4 refs., 6 figs., 3 tabs.

  3. Comparison of Hydrogen Sulfide Analysis Techniques

    ERIC Educational Resources Information Center

    Bethea, Robert M.

    1973-01-01

    A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)

  4. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones... the platform or completion unit, including, but not limited to operations such as blowing the...

  5. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain... completion unit, including, but not limited to operations such as blowing the well down, dismantling...

  6. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain... completion unit, including, but not limited to operations such as blowing the well down, dismantling...

  7. 30 CFR 250.504 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain... completion unit, including, but not limited to operations such as blowing the well down, dismantling...

  8. Sulfur recovery from low hydrogen sulfide gases

    SciTech Connect

    Chute, A.E.

    1982-10-01

    Describes processes for recovering sulfur from acid gases containing less hydrogen sulfide than can be processed satisfactorily in a typical Claus sulfur recovery unit (as shown in diagram). One feature of the Recycle Selectox process is that the circulating gas acts like a flywheel to maintain steady operating conditions, even when the acid gas feed fluctuates. When the acid gas concentration falls below that which can be handled in a Claus or Selectox plant, direct conversion in a Stretford of similar process such as Unisulf is indicated. When the acid gases are weak in hydrogen sulfide, there are several considerations in conditioning the feed gas. Most of the hydrocarbons entering a Clause plant are oxidized to water and oxides of carbon. The weaker the acid gas feed, the greater is the advantage in using the Recycle Selectox process. Below 30%, the sulfur-burning Claus process can be applied. At 30% and lower, or even at higher concentrations, the Recycle Selectox or Selectox process offers a simpler yet effective means of converting and recovering sulfur. Concludes that simple modifications to the Claus process are adequate to convert hydrogen sulfide to elemental sulfur from reasonably prepared acid gases (CO/sub 2/ + H/sub 2/S) having hydrogen sulfide concentrations as low as 30%.

  9. Wheat straw cover for reducing ammonia and hydrogen sulfide emissions from dairy manure storage

    SciTech Connect

    Xue, S.K.; Hermanson, R.E.

    1999-08-01

    Analysis of the use of a wheat straw cover for reducing ammonia and hydrogen sulfide emissions from liquid manure was conducted in both a laboratory and a pilot system. Two straw covers with different thicknesses (5 cm and 10 cm) were evaluated for their effectiveness in reducing odorous gas emissions. The rates of ammonia and hydrogen sulfide emissions from the treatments were monitored; concentrations of ammonia, dissolved sulfide, chemical oxygen demand (COD), and pH of the liquid manure were measured. Additionally, the overall mass transfer coefficients of ammonia and hydrogen sulfide were calculated for the conditions of the experiment. The results demonstrated that both the 5-cm and 10-cm straw covers were effective in reducing ammonia and hydrogen sulfide emissions from manure storage. In the laboratory tests, when a crust formed on the manure surface within three to four weeks after the straw application, ammonia emissions were reduced by up to 95%. A similar trend was observed in the pilot experiments in the field. Hydrogen sulfide emissions were suppressed by 95% with the wheat straw cover. The mass transfer coefficients of hydrogen sulfide with the straw covers were significantly lower than those of the control, which indicated the effectiveness of a straw cover as a physical barrier for reducing hydrogen sulfide emissions. Reduced pH and decreased ammonia that biological reactions might also be a factor contributing to the emission reductions.

  10. Evaluation of hydrogen sulfide conversion processes. Final report, May 1, 1987-October 15, 1989

    SciTech Connect

    Krishnan, G.N.; Pound, B.G.

    1989-10-01

    The research was sponsored by the Gas Research Institute to evaluate the status of hydrogen sulfide conversion processes and to recommend areas of research that are of interest to the natural gas industry. Several processes that convert hydrogen sulfide to sulfur and water were reviewed and they include Claus process, Claus plant tail gas treatment processes, liquid phase oxidation processes and direct catalytic oxidation processes. Electrochemical, photochemical, thermal, thermochemical and plasmachemical methods of producing both hydrogen and sulfur from hydrogen sulfide were also reviewed.

  11. Redetermination of piperidinium hydrogen sulfide structure

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    The presence of adventitious water in a reaction between dicyclopentamethylene thiuram-disulfide (C5H10NCS2)(sub 2) and a picoline solution of tricyclopentadienyl indium(III) (C5H5)(sub 3). It resulted in the formation of piperidinium hydrogen sulfide (C5H13NS). The piperidinium hydrogen sulfide produced in this way was unambiguously characterized by X-ray crystallography. The structure determination showed that the piperidinium hydrogen sulfide crystal (MW = 119.23 g/mol) has an orthorhombic (Pbcm) unit cell whose parameters are: a = 9.818(2), b = 7.3720(1), c = 9.754(1) A, V = 706.0(3) A(exp 3), Z=4. D(sub chi) = 1.122 g cm(exp -3), Mo K(alpha) (lamda = 0.71073), mu= 3.36 cm(exp -1), F(000) = 264.0, T =293 K, R = 0.036 for 343 reflections with F(sub O)(sup 2) greater than 3 sigma (F(sub O)(sup 2)) and 65 variables. The compound consists of (C5H10NH2)(+) cations and (SH)(-) anions with both species residing on crystallographic mirror planes. N-H -- S hydrogen bonding contributes to the interconnection of neighboring piperidinium components of the compound.

  12. Removal of hydrogen sulfide from drilling fluids

    SciTech Connect

    Gilligan Jr., T. J.

    1985-10-22

    The present invention relates to a process for scavenging hydrogen sulfide which frequently becomes entrained in drilling fluid during the course of drilling operations through subterranean formations. The process consists of introducing a solid oxidant in powdered form into the circulating drilling fluid when hydrogen sulfide is encountered. The solid oxidants are selected from the group consisting of calcium hypochlorite (Ca-(OCl)/sub 2/), sodium perborate (NaBO/sub 3/), potassium permanganate (KMnO/sub 4/), and potassium peroxydisulfate (K/sub 2/S/sub 2/O/sub 8/). The solid oxidants are soluble in the drilling fluid, promoting fast and complete scavenging reactions without adversely altering the drilling fluid rheology.

  13. Hydrogen sulfide prodrugs—a review

    PubMed Central

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-01-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  14. Hydrogen attack - Influence of hydrogen sulfide. [on carbon steel

    NASA Technical Reports Server (NTRS)

    Eliezer, D.; Nelson, H. G.

    1978-01-01

    An experimental study is conducted on 12.5-mm-thick SAE 1020 steel (plain carbon steel) plate to assess hydrogen attack at room temperature after specimen exposure at 525 C to hydrogen and a blend of hydrogen sulfide and hydrogen at a pressure of 3.5 MN/sq m for exposure times up to 240 hr. The results are discussed in terms of tensile properties, fissure formation, and surface scales. It is shown that hydrogen attack from a high-purity hydrogen environment is severe, with the formation of numerous methane fissures and bubbles along with a significant reduction in the room-temperature tensile yield and ultimate strengths. However, no hydrogen attack is observed in the hydrogen/hydrogen sulfide blend environment, i.e. no fissure or bubble formation occurred and the room-temperature tensile properties remained unchanged. It is suggested that the observed porous discontinuous scale of FeS acts as a barrier to hydrogen entry, thus reducing its effective equilibrium solubility in the iron lattice. Therefore, hydrogen attack should not occur in pressure-vessel steels used in many coal gasification processes.

  15. Structure of 4-methylpyridinium Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Andras, Maria T.; Hepp, Aloysius F.; Fanwick, Phillip E.; Martuch, Robert A.; Duraj, Stan A.; Gordon, Edward M.

    1994-01-01

    4-Methylpyridinium hydrogen sulfide, (C6H7NH)HS, M(sub r) = 127.21, consists of C6H7NH(+) cations and HS(-) anions. Z = 2 for the crystal with monoclinic space group Cm (#8), dimensions of a = 8.679(2) A, b = 7.964(1) A, and c = 4.860(2) A, an angle beta of 101.10(2) degrees, and a volume of V = 329.6(3) A(exp 3). R = 0.039 and R(sub w) = 0.048 for 385 reflections with F(sub o)(exp 2) greater than 3 sigma(F(sub o)(exp 2)) and 59 variables. Both the C6H7NH(+) cation and the HS(-) anion lie on crystallographic mirror planes with the N,S, two carbon atoms, and two hydrogen atoms positioned in the planes. The hydrogen atom of the HS(-) anion was not located.

  16. High temperature regenerable hydrogen sulfide removal agents

    SciTech Connect

    Copeland, Robert J.

    1993-01-01

    A system for high temperature desulfurization of coal-derived gases using regenerable sorbents. One sorbent is stannic oxide (tin oxide, SnO.sub.2), the other sorbent is a metal oxide or mixed metal oxide such as zinc ferrite (ZnFe.sub.2 O.sub.4). Certain otherwise undesirable by-products, including hydrogen sulfide (H.sub.2 S) and sulfur dioxide (SO.sub.2) are reused by the system, and elemental sulfur is produced in the regeneration reaction. A system for refabricating the sorbent pellets is also described.

  17. Amorphous molybdenum sulfides as hydrogen evolution catalysts.

    PubMed

    Morales-Guio, Carlos G; Hu, Xile

    2014-08-19

    Providing energy for a population projected to reach 9 billion people within the middle of this century is one of the most pressing societal issues. Burning fossil fuels at a rate and scale that satisfy our near-term demand will irreversibly damage the living environment. Among the various sources of alternative and CO2-emission-free energies, the sun is the only source that is capable of providing enough energy for the whole world. Sunlight energy, however, is intermittent and requires an efficient storage mechanism. Sunlight-driven water splitting to make hydrogen is widely considered as one of the most attractive methods for solar energy storage. Water splitting needs a hydrogen evolution catalyst to accelerate the rate of hydrogen production and to lower the energy loss in this process. Precious metals such as Pt are superior catalysts, but they are too expensive and scarce for large-scale applications. In this Account, we summarize our recent research on the preparation, characterization, and application of amorphous molybdenum sulfide catalysts for the hydrogen evolution reaction. The catalysts can be synthesized by electrochemical deposition under ambient conditions from readily available and inexpensive precursors. The catalytic activity is among the highest for nonprecious catalysts. For example, at a loading of 0.2 mg/cm(2), the optimal catalyst delivers a current density of 10 mA/cm(2) at an overpotential of 160 mV. The growth mechanism of the electrochemically deposited film catalysts was revealed by an electrochemical quartz microcrystal balance study. While different electrochemical deposition methods produce films with different initial compositions, the active catalysts are the same and are identified as a "MoS(2+x)" species. The activity of the film catalysts can be further promoted by divalent Fe, Co, and Ni ions, and the origins of the promotional effects have been probed. Highly active amorphous molybdenum sulfide particles can also be prepared from simple wet-chemical routes. Electron transport is sometimes slow in the particle catalysts, and an impedance model has been established to identify this slow electron transport. Finally, the amorphous molybdenum sulfide film catalyst has been integrated onto a copper(I) oxide photocathode for photoelectrochemical hydrogen evolution. The conformal catalyst efficiently extracts the excited electrons to give an impressive photocurrent density of -5.7 mA/cm(2) at 0 V vs RHE. The catalyst also confers good stability. PMID:25065612

  18. Hydrogen sulfide and polysulfides as signaling molecules

    PubMed Central

    KIMURA, Hideo

    2015-01-01

    Hydrogen sulfide (H2S) is a familiar toxic gas that smells of rotten eggs. After the identification of endogenous H2S in the mammalian brain two decades ago, studies of this molecule uncovered physiological roles in processes such as neuromodulation, vascular tone regulation, cytoprotection against oxidative stress, angiogenesis, anti-inflammation, and oxygen sensing. Enzymes that produce H2S, such as cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase have been studied intensively and well characterized. Polysulfides, which have a higher number of inner sulfur atoms than that in H2S, were recently identified as potential signaling molecules that can activate ion channels, transcription factors, and tumor suppressors with greater potency than that of H2S. This article focuses on our contribution to the discovery of these molecules and their metabolic pathways and mechanisms of action. PMID:25864468

  19. Signaling of hydrogen sulfide and polysulfides.

    PubMed

    Kimura, Hideo

    2015-02-10

    It has been almost two decades since the first demonstration of hydrogen sulfide (H2S) as a physiological mediator of cognitive function and vascular tone. H2S is physiologically important because it protects various organs from ischemia-reperfusion injury besides regulating inflammation, oxygen sensing, cell growth, and senescence. The production, metabolism, and regulation of H2S have been studied extensively. H2S modulates target proteins through sulfhydration (or sulfuration) or by the reduction of cysteine disulfide bonds. A large number of novel H2S-donating compounds are being developed owing to the therapeutic potential of H2S. Recently, polysulfides, rather than H2S, have been identified as molecules that sulfhydrate (or sulfurate) their target proteins. PMID:25178405

  20. Chemical Foundations of Hydrogen Sulfide Biology

    PubMed Central

    Li, Qian; Lancaster, Jack R.

    2013-01-01

    Following nitric oxide (nitrogen monoxide) and carbon monoxide, hydrogen sulfide (or its newer systematic name sulfane, H2S) became the third small molecule that can be both toxic and beneficial depending on the concentration. In spite of its impressive therapeutic potential, the underlying mechanisms for its beneficial effects remain unclear. Any novel mechanism has to obey fundamental chemical principles. H2S chemistry was studied long before its biological relevance was discovered, however, with a few exceptions, these past works have received relatively little attention in the path of exploring the mechanistic conundrum of H2S biological functions. This review calls attention to the basic physical and chemical properties of H2S, focuses on the chemistry between H2S and its three potential biological targets: oxidants, metals and thiol derivatives, discusses the applications of these basics into H2S biology and methodology, and introduces the standard terminology to this youthful field. PMID:23850631

  1. Hydrogen sulfide exposure in an adult male

    PubMed Central

    Doujaiji, Bassam; Al-Tawfiq, Jaffar A.

    2010-01-01

    Hydrogen sulfide (H2S) is responsible for many incidents of occupational toxic exposure, especially in the petroleum industry. The clinical effects of H2S depend on its concentration and the duration of exposure. H2S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure. H2S may also affect multiple organs, causing temporary or permanent derangements in the nervous, cardiovascular, renal, hepatic, and hematological systems. We present a case of occupational exposure to H2S leading to multi-organ involvement, acute respiratory failure, organizing pneumonia, and shock resembling acute sepsis. The patient also developed mild obstructive and restrictive pulmonary disease and peripheral neuropathy. PMID:20103963

  2. Hydrogen Production from Hydrogen Sulfide in IGCC Power Plants

    SciTech Connect

    Elias Stefanakos; Burton Krakow; Jonathan Mbah

    2007-07-31

    IGCC power plants are the cleanest coal-based power generation facilities in the world. Technical improvements are needed to help make them cost competitive. Sulfur recovery is one procedure in which improvement is possible. This project has developed and demonstrated an electrochemical process that could provide such an improvement. IGCC power plants now in operation extract the sulfur from the synthesis gas as hydrogen sulfide. In this project H{sub 2}S has been electrolyzed to yield sulfur and hydrogen (instead of sulfur and water as is the present practice). The value of the byproduct hydrogen makes this process more cost effective. The electrolysis has exploited some recent developments in solid state electrolytes. The proof of principal for the project concept has been accomplished.

  3. NEAR-CONTINUOUS MEASUREMENT OF HYDROGEN SULFIDE AND CARBONYL SULFIDE BY AN AUTOMATIC GAS CHROMATOGRAPH

    EPA Science Inventory

    An automatic gas chromatograph with a flame photometric detector that samples and analyzes hydrogen sulfide and carbonyl sulfide at 30-s intervals is described. Temperature programming was used to elute trace amounts of carbon disulfide present in each injection from a Supelpak-S...

  4. Photocatalytic decomposition of hydrogen sulfide on cadmium and zinc sulfides immobilized on a cation exchange film

    SciTech Connect

    Makhmadmurodov, A.; Gruzdkov, Y.A.; Parmon, V.N.; Savinov, E.N.

    1986-08-01

    The photocatalytic decomposition of hydrogen sulfide on cadmium, zinc, and tin sulfides, immobilized on a polymer, was studied. Activation of the photocatalyst by finely divided particles of Pd and Pt was used. A quantum yield of 9.5% was achieved.

  5. Role of Hydrogen Sulfide in Paramyxovirus Infections

    PubMed Central

    Li, Hui; Ma, Yinghong; Escaffre, Oliver; Ivanciuc, Teodora; Komaravelli, Narayana; Kelley, John P.; Coletta, Ciro; Szabo, Csaba; Rockx, Barry; Garofalo, Roberto P.

    2015-01-01

    ABSTRACT Hydrogen sulfide (H2S) is an endogenous gaseous mediator that has gained increasing recognition as an important player in modulating acute and chronic inflammatory diseases. However, its role in virus-induced lung inflammation is currently unknown. Respiratory syncytial virus (RSV) is a major cause of upper and lower respiratory tract infections in children for which no vaccine or effective treatment is available. Using the slow-releasing H2S donor GYY4137 and propargylglycin (PAG), an inhibitor of cystathionine-γ-lyase (CSE), a key enzyme that produces intracellular H2S, we found that RSV infection led to a reduced ability to generate and maintain intracellular H2S levels in airway epithelial cells (AECs). Inhibition of CSE with PAG resulted in increased viral replication and chemokine secretion. On the other hand, treatment of AECs with the H2S donor GYY4137 reduced proinflammatory mediator production and significantly reduced viral replication, even when administered several hours after viral absorption. GYY4137 also significantly reduced replication and inflammatory chemokine production induced by human metapneumovirus (hMPV) and Nipah virus (NiV), suggesting a broad inhibitory effect of H2S on paramyxovirus infections. GYY4137 treatment had no effect on RSV genome replication or viral mRNA and protein synthesis, but it inhibited syncytium formation and virus assembly/release. GYY4137 inhibition of proinflammatory gene expression occurred by modulation of the activation of the key transcription factors nuclear factor κB (NF-κB) and interferon regulatory factor 3 (IRF-3) at a step subsequent to their nuclear translocation. H2S antiviral and immunoregulatory properties could represent a novel treatment strategy for paramyxovirus infections. IMPORTANCE RSV is a global health concern, causing significant morbidity and economic losses as well as mortality in developing countries. After decades of intensive research, no vaccine or effective treatment, with the exception of immunoprophylaxis, is available for this infection as well as for other important respiratory mucosal viruses. This study identifies hydrogen sulfide as a novel cellular mediator that can modulate viral replication and proinflammatory gene expression, both important determinants of lung injury in respiratory viral infections, with potential for rapid translation of such findings into novel therapeutic approaches for viral bronchiolitis and pneumonia. PMID:25740991

  6. An Experiment in Autotrophic Fermentation: Microbial Oxidation of Hydrogen Sulfide.

    ERIC Educational Resources Information Center

    Sublette, Kerry L.

    1989-01-01

    Described is an experiment which uses an autotrophic bacterium to anaerobically oxidize hydrogen sulfide to sulfate in a batch-stirred tank reactor. Discusses background information, experimental procedure, and sample results of this activity. (CW)

  7. Control of hydrogen sulfide emission from geothermal steam plants with hydrogen peroxide and sodium vanadate

    SciTech Connect

    Brown, R.A.; Hills, W.A.

    1982-11-30

    Removing hydrogen sulfide from geothermal steam condensate is described whereby the hydrogen sulfide that is present in the condensate from a geothermal steam plant is oxidized with a peroxygen compound such as hydrogen peroxide in the presence of catalytic quantities of sodium vanadate under neutral to alkaline conditions.

  8. Sulfides in the Anaerobic Environment: The Determination of Hydrogen Sulfide and Acid-Soluble Metallic Sulfides in Sea-Floor Sediment

    NASA Astrophysics Data System (ADS)

    Christensen, Joan Kai; Høyer, Boy; Kryger, Lars; Pind, Niels; Kong, Lee Sing

    1998-12-01

    A procedure for the determination of hydrogen sulfide and acid-soluble metallic sulfides in sea floor sediment has been developed and tested as part of a laboratory course in analytical and environmental chemistry. The procedure includes (i) anaerobic sampling of sediment, (ii) a volatilization method, which discriminates between hydrogen sulfide and acid-soluble metallic sulfides in the sediment, and (iii) a quantitative determination of these sulfide components using an ion-selective electrode approach. The paper describes all experimental details and gives a brief summary of sulfide generation processes in sea-floor sediments, underlining the importance of sulfides in anaerobic environments. Representative results obtained during the laboratory course are discussed.

  9. Hydrogen sulfide as a vasculoprotective factor

    PubMed Central

    2013-01-01

    Hydrogen sulfide is a novel mediator with the unique properties of a gasotransmitter and many and varied physiological effects. Included in these effects are a number of cardiovascular effects that are proving beneficial to vascular health. Specifically, H2S can elicit vasorelaxation, prevention of inflammation and leukocyte adhesion, anti-proliferative effects and anti-thrombotic effects. Additionally, H2S is a chemical reductant and nucleophile that is capable of inhibiting the production of reactive oxygen species, scavenging and neutralising reactive oxygen species and boosting the efficacy of endogenous anti-oxidant molecules. These result in resistance to oxidative stress, protection of vascular endothelial function and maintenance of blood flow and organ perfusion. H2S has been shown to be protective in hypertension, atherosclerosis and under conditions of vascular oxidative stress, and deficiency of endogenous H2S production is linked to cardiovascular disease states. Taken together, these effects suggest that H2S has a physiological role as a vasculoprotective factor and that exogenous H2S donors may be useful therapeutic agents. This review article will discuss the vascular effects and anti-oxidant properties of H2S as well as examine the protective role of H2S in some important vascular disease states. PMID:23628084

  10. Hydrogen Sulfide Signaling in the Gastrointestinal Tract

    PubMed Central

    2014-01-01

    Abstract Significance: The current literature regarding the effects of the gaseous signal molecule hydrogen sulfide (H2S) in the gastrointestinal system is reviewed. Bacterial, host and pharmaceutical-derived H2S are all considered and presented according to the physiological or pathophysiological effects of the gaseous signal molecule. These subjects include the toxicology of intestinal H2S with emphasis on bacterial-derived H2S, especially from sulfate-reducing bacteria, the role of endogenous and exogenous H2S in intestinal inflammation, and the roles of H2S in gastrointestinal motility, secretion and nociception. Recent Advances: While its pro- and anti-inflammatory, smooth muscle relaxant, prosecretory, and pro- and antinociceptive actions continue to remain the major effects of H2S in this system; recent findings have expanded the potential molecular targets for H2S in the gastrointestinal tract. Critical Issues: Numerous discrepancies remain in the literature, and definitive molecular targets in this system have not been supported by the use of competitive antagonism. Future Directions: Future work will hopefully resolve discrepancies in the literature and identify molecular targets and mechanisms of action for H2S. It is clear from the current literature that the long-appreciated relationship between H2S and the gastrointestinal tract continues to be strong as we endeavor to unravel its mysteries. Antioxid. Redox Signal. 20, 818–830. PMID:23582008

  11. Hydrogen Sulfide and Cellular Redox Homeostasis

    PubMed Central

    Xie, Zhi-Zhong; Liu, Yang; Bian, Jin-Song

    2016-01-01

    Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S) is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H2S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H2S are still poorly comprehended. This review presents an overview of the current understanding of H2S specially focusing on the new understanding and mechanisms of the antioxidant effects of H2S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H2S-induced S-sulfhydration of key proteins (e.g., p66Shc and Keap1) is also one of the focuses of this review. PMID:26881033

  12. Detection of thiol modifications by hydrogen sulfide.

    PubMed

    Williams, E; Pead, S; Whiteman, M; Wood, M E; Wilson, I D; Ladomery, M R; Teklic, T; Lisjak, M; Hancock, J T

    2015-01-01

    Hydrogen sulfide (H2S) is an important gasotransmitter in both animals and plants. Many physiological events, including responses to stress, have been suggested to involve H2S, at least in part. On the other hand, numerous responses have been reported following treatment with H2S, including changes in the levels of antioxidants and the activities of transcription factors. Therefore, it is important to understand and unravel the events that are taking place downstream of H2S in signaling pathways. H2S is known to interact with other reactive signaling molecules such as reactive oxygen species (ROS) and nitric oxide (NO). One of the mechanisms by which ROS and NO have effects in a cell is the modification of thiol groups on proteins, by oxidation or S-nitrosylation, respectively. Recently, it has been reported that H2S can also modify thiols. Here we report a method for the determination of thiol modifications on proteins following the treatment with biological samples with H2S donors. Here, the nematode Caenorhabditis elegans is used as a model system but this method can be used for samples from other animals or plants. PMID:25747483

  13. Signaling Molecules: Hydrogen Sulfide and Polysulfide

    PubMed Central

    2015-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a signaling molecule as well as a cytoprotectant. It modulates neurotransmission, regulates vascular tone, and protects various tissues and organs, including neurons, the heart, and kidneys, from oxidative stress and ischemia-reperfusion injury. H2S is produced from l-cysteine by cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3MST) along with cysteine aminotransferase. Recent Advances: In addition to these enzymes, we recently identified a novel pathway to produce H2S from d-cysteine, which involves d-amino acid oxidase (DAO) along with 3MST. These enzymes are localized in the cytoplasm, mitochondria, and peroxisomes. However, some enzymes translocate to organelles under specific conditions. Moreover, H2S-derived potential signaling molecules such as polysulfides and HSNO have been identified. Critical Issues: The physiological stimulations, which trigger the production of H2S and its derivatives and maintain their local levels, remain unclear. Future Directions: Understanding the regulation of the H2S production and H2S-derived signaling molecules and the specific stimuli that induce their release will provide new insights into the biology of H2S and therapeutic development in diseases involving these substances. Antioxid. Redox Signal. 22, 362–376. PMID:24800864

  14. Production and Physiological Effects of Hydrogen Sulfide

    PubMed Central

    2014-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions. It regulates synaptic transmission, vascular tone, inflammation, transcription, and angiogenesis; protects cells from oxidative stress and ischemia-reperfusion injury; and promotes healing of ulcers. Recent Advances: In addition to cystathionine β-synthase and cystathionine γ-lyase, 3-mercaptopyruvate sulfurtransferase along with cysteine aminotransferase was recently demonstrated to produce H2S. Even in bacteria, H2S produced by these enzymes functions as a defense against antibiotics, suggesting that the cytoprotective effect of H2S is a universal defense mechanism in organisms from bacteria to mammals. Critical Issues: The functional form of H2S—undissociated H2S gas, dissociated HS ion, or some other form of sulfur—has not been identified. Future Directions: The regulation of H2S production by three enzymes may lead to the identification of the physiological signals that are required to release H2S. The identification of the physiological functions of other forms of sulfur may also help understand the biological significance of H2S. Antioxid. Redox Signal. 20, 783–793. PMID:23581969

  15. Measurement of plasma hydrogen sulfide in vivo and in vitro

    PubMed Central

    Shen, Xinggui; Pattillo, Christopher B.; Pardue, Sibile; Bir, Shyamal C.; Wang, Rui; Kevil, Christopher G.

    2015-01-01

    The gasotransmitter hydrogen sulfide is known to regulate multiple cellular functions during normal and pathophysiological states. However, a paucity of concise information exists regarding quantitative amounts of hydrogen sulfide involved in physiological and pathological responses. This is primarily due to disagreement among various methods employed to measure free hydrogen sulfide. In this article, we describe a very sensitive method of measuring the presence of H2S in plasma down to nanomolar levels, using monobromobimane (MBB). The current standard assay using methylene blue provides erroneous results that do not actually measure H2S. The method presented herein involves derivatization of sulfide with excess MBB in 100 mM Tris–HCl buffer (pH 9.5, 0.1 mM DTPA) for 30 min in 1% oxygen at room temperature. The fluorescent product sulfide-dibimane (SDB) is analyzed by RP-HPLC using an eclipse XDB-C18 (4.6×250 mm) column with gradient elution by 0.1% (v/v) trifluoroacetic acid in acetonitrile. The limit of detection for sulfide-dibimane is 2 nM and the SDB product is very stable over time, allowing batch storage and analysis. In summary, our MBB method is suitable for sensitive quantitative measurement of free hydrogen sulfide in multiple biological samples such as plasma, tissue and cell culture lysates, or media. PMID:21276849

  16. Fatal hydrogen sulfide poisoning at a dye works.

    PubMed

    Kage, Shigetoshi; Ikeda, Hideaki; Ikeda, Noriaki; Tsujita, Akira; Kudo, Keiko

    2004-07-01

    An adult Japanese man (A) entered a pit to remove sludge in a drainage pipe at a dye works in Japan. When he took off a joint of the pipe, the sludge in the pipe flowed into the pit. As he suddenly lost consciousness, three colleagues (B, C, D) entered the pit to rescue him. All of these (A, B, C and D) lost consciousness in the pit, and died soon after the accident. Since hydrogen sulfide gas was detected in the sludge of the pit, gas poisoning was suspected. Toxicological analyses of sulfide and thiosulfate, a metabolite of sulfide, in blood and urine of the victims were made, using the extractive alkylation technique combined with gas chromatography/mass spectrometry. Sulfide and thiosulfate were detected in whole blood of the four workers at levels of 0.32-9.36 mg/l and 0.11-0.23 mmol/l, respectively. These concentrations were at least 6-187 times higher in sulfide and 37-77 times higher in thiosulfate than those in healthy persons, and were similar to values found in fatal cases of hydrogen sulfide poisoning. Thiosulfate was not detected in the urine of four workers, which indicated acute death. Based on these results, all four patients were victims of hydrogen sulfide poisoning, who died soon after the exposure. PMID:15231289

  17. Hydrogen Sulfide as an Oxygen Sensor

    PubMed Central

    2015-01-01

    Abstract Significance Although oxygen (O2)-sensing cells and tissues have been known for decades, the identity of the O2-sensing mechanism has remained elusive. Evidence is accumulating that O2-dependent metabolism of hydrogen sulfide (H2S) is this enigmatic O2 sensor. Recent Advances The elucidation of biochemical pathways involved in H2S synthesis and metabolism have shown that reciprocal H2S/O2 interactions have been inexorably linked throughout eukaryotic evolution; there are multiple foci by which O2 controls H2S inactivation, and the effects of H2S on downstream signaling events are consistent with those activated by hypoxia. H2S-mediated O2 sensing has been demonstrated in a variety of O2-sensing tissues in vertebrate cardiovascular and respiratory systems, including smooth muscle in systemic and respiratory blood vessels and airways, carotid body, adrenal medulla, and other peripheral as well as central chemoreceptors. Critical Issues Information is now needed on the intracellular location and stoichometry of these signaling processes and how and which downstream effectors are activated by H2S and its metabolites. Future Directions Development of specific inhibitors of H2S metabolism and effector activation as well as cellular organelle-targeted compounds that release H2S in a time- or environmentally controlled way will not only enhance our understanding of this signaling process but also provide direction for future therapeutic applications. Antioxid. Redox Signal. 22, 377–397. “Nothing in Biology Makes Sense Except in the Light of Evolution” —Theodosius Dobzhansky (29) PMID:24801248

  18. Hydrogen Sulfide in Biochemistry and Medicine

    PubMed Central

    Predmore, Benjamin Lee; Lefer, David Joseph

    2012-01-01

    Abstract Significance: An abundance of experimental evidence suggests that hydrogen sulfide (H2S) plays a prominent role in physiology and pathophysiology. Many targets exist for H2S therapy. The molecular targets of H2S include proteins, enzymes, transcription factors, and membrane ion channels. Recent Advances: Novel H2S precursors are being synthesized and discovered that are capable of releasing H2S in a slow and sustained manner. This presents a novel and advantageous approach to H2S therapy for treatment of chronic conditions associated with a decline in endogenous H2S, such as diabetes and cardiovascular disease. Critical Issues: While H2S is cytoprotective at physiological concentrations, it is not universally cytoprotective, as it appears to have pro-apoptotic actions in cancer cells and is well known to be toxic at supraphysiological concentrations. Many of the pleiotropic effects of H2S on health are associated with the inhibition of inflammation and upregulation of prosurvival pathways. The powerful anti-inflammatory, cytoprotective, immunomodulating, and trophic effects of H2S on the vast majority of normal cells seem to be mediated mainly by its actions as an extremely versatile direct and indirect antioxidant and free radical scavenger. While the overall effects of H2S on transformed (i.e., malignant) cells can be characterized as pro-oxidant and pro-apoptotic, they contrast sharply with the cytoprotective effects on most normal cells. Future Directions: H2S has become a molecule of great interest, and several slow-releasing H2S prodrugs are currently under development. We believe that additional agents regulating H2S bioavailability will be developed during the next 10 years. Antioxid. Redox Signal. 17, 119–140. PMID:22432697

  19. Determination of Hydrogen Sulfide in Fermentation Broths Containing SO21

    PubMed Central

    Acree, T. E.; Sonoff, Elisabeth P.; Splittstoesser, D. F.

    1971-01-01

    A procedure for the determination of hydrogen sulfide in fermentation broths containing up to 100 ?g of SO2 per ml is described. The method involves the sparging of H2S from the broth into a cadmium hydroxide absorption solution, the formation of methylene blue from the absorbed sulfide, and the measuring of this color spectrophotometrically. The use of cadmium hydroxide instead of zinc acetate, the common absorbent, substantially reduced the interference of SO2 with the analysis. PMID:5111300

  20. Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water

    NASA Technical Reports Server (NTRS)

    Ota, K.; Conger, W. L.

    1977-01-01

    The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

  1. Creation of active sites by impregnation of carbon fibers: application to the fixation of hydrogen sulfide.

    PubMed

    Meljac, Laure; Perier-Camby, Laurent; Thomas, Grard

    2004-06-01

    Activated carbon fibers, which exhibit high specific area and numerous active surface sites, constitute very powerful adsorbents and are widely used in filtration to eliminate pollutants from liquid or gaseous effluents. The fibers studied in this work are devoted to the filtration of gaseous effluent containing very small amounts (few vpm) of hydrogen sulfide. Preliminary experiments evidenced that these fibers weakly adsorb hydrogen sulfide. To improve their fixation capacity toward H(2)S the activated fibers are impregnated in an aqueous solution of potassium hydroxide. The impregnation treatment usually takes place before activation but in this work it occurs at room temperature after activation of the fibers. A further thermal treatment is performed to increase the efficiency of the system. The overall treatment leads to the creation of basic sites showing a great activity for H(2)S gas in the presence of water vapor. The mechanism has been established by a series of characterizations before, during, and after the different operation units. The KOH deposited after impregnation is carbonated into KHCO(3) at room temperature and then decomposed into K(2)CO(3) during the thermal treatment. K(2)CO(3) and H(2)S dissolve in a liquid aqueous solution formed on the fiber surface. Then carbonate ions and H(2)S molecules react together almost completely to yield HS(-) species. As a consequence the sorption capacities of hydrogen sulfide on the impregnated fibers are much higher, even for small hydrogen sulfide volume fractions. PMID:15120288

  2. [Evaluation of methods for monitoring air concentrations of hydrogen sulfide].

    PubMed

    Janoszka, Katarzyna; Wziatek, Agata; Gromiec, Jan P

    2013-01-01

    The development of different branches of industry and a growing fossil fuels minming results in a considerable emission of by-products. Major air pollutants are: CO, CO2, SO2, SO3, H2S, nitrogen oxides, as well as compounds of an organic arigin. The main aspects of this paper is to review and evaluate methods used for monitoring of hydrogen sulfide in the air. Different instrumental techniques were discussed, electrochemical, chromatographic and spectrophotometric (wet and dry), to select the method most suitable for monitoring low levels of hydrogen sulfide, close to its odor threshold. Based on the literature review the method for H2S determination in the air, involving absorption in aqueous zinc acetate and reaction with N,N-dimethylo-p-phenylodiamine and FeCl3, has been selected and preliminary verified. The adopted method allows for routine measurements of low concentration of hydrogen sulfide, close to its odor threshold in workplaces and ambient air. PMID:24261256

  3. Nature creates, adapts, protects and sustains life using hydrogen sulfide.

    PubMed

    Tabibzadeh, Siamak

    2016-01-01

    Life emerged on Earth in an anaerobic environment, bathed in noxious gases. Among these gases, the role of hydrogen sulfide is significant since this gas, was required as a building block of life, contributed to abiogenic generation of organic compounds that gave rise to life and drove adaptations of life throughout its entire evolutionary path. During evolution, hydrogen sulfide contributed to sustaining life in face of harsh environmental conditions. Modern cells still utilize hydrogen sulfide as a signaling molecule, in pro and anti-inflammatory responses, for acquisition of tolerance against damage, in directing repair responses, as a source of energy and in modifying their genetic makeup and function to acquire a phenotype reminiscent of early life forms. PMID:26709792

  4. Hydrogen sulfide: physiological properties and therapeutic potential in ischaemia

    PubMed Central

    Bos, Eelke M; van Goor, Harry; Joles, Jaap A; Whiteman, Matthew; Leuvenink, Henri G D

    2015-01-01

    Hydrogen sulfide (H2S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia. Linked Articles This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6 PMID:25091411

  5. Liquid Hydrogen: Target, Detector

    SciTech Connect

    Mulholland, G.T.; Harigel, G.G.

    2004-06-23

    In 1952 D. Glaser demonstrated that a radioactive source's radiation could boil 135 deg. C superheated-diethyl ether in a 3-mm O glass vessel and recorded bubble track growth on high-speed film in a 2-cm3 chamber. This Bubble Chamber (BC) promised improved particle track time and spatial resolution and cycling rate. Hildebrand and Nagle, U of Chicago, reported Liquid Hydrogen minimum ionizing particle boiling in August 1953. John Wood created the 3.7-cm O Liquid Hydrogen BC at LBL in January 1954. By 1959 the Lawrence Berkley Laboratory (LBL) Alvarez group's '72-inch' BC had tracks in liquid hydrogen. Within 10 years bubble chamber volumes increased by a factor of a million and spread to every laboratory with a substantial high-energy physics program. The BC, particle accelerators and special separated particle beams created a new era of High Energy Physics (HEP) experimentation. The BC became the largest most complex cryogenic installation at the world's HEP laboratories for decades. The invention and worldwide development, deployment and characteristics of these cryogenic dynamic target/detectors and related hydrogen targets are described.

  6. Liquid-Hydrogen Polygeneration System

    NASA Technical Reports Server (NTRS)

    Minderman, P.; Gutkowski, G.; Manfredi, L.; King, J.; Howard, F.

    1986-01-01

    Polygeneration system uses existing technology in integrated process to produce liquid hydrogen space-vehicle propellant and secondary products as gaseous nitrogen, electrical energy, and thermal energy. Makes commercial launch services economical. Lowers expected cost of liquid hydrogen by utilizing relatively cheap coal feedstocks and by reducing electrical costs associated with producing liquid hydrogen.

  7. Removing hydrogen sulfide from geothermal gases: hypochlorite process reduces hydrogen sulfide emissions to acceptable levels. NTIS tech note

    SciTech Connect

    Not Available

    1981-10-01

    This citation summarizes a one-page announcement of technology available for utilization. A hypochlorite process has been proposed as an alternative to other methods for the removal of hydrogen sulfide from the exhaust gases of geothermal powerplants. An electrolytically-generated sodium hypochlorite solution converts the hydrogen sulfide to water, salt, and sulfur. The hypochlorite process appears to be less expensive than competing processes for most of the cases studied. ...FOR ADDITIONAL INFORMATION: Detailed information about the technology described may be obtained by ordering the NTIS report, order number: DOE/ER/1092-T7, price code: PC A03.

  8. Determination of hydrogen sulfide and volatile thiols in air samples by mercury probe derivatization coupled with liquid chromatography-atomic fluorescence spectrometry.

    PubMed

    Bramanti, Emilia; D'Ulivo, Lucia; Lomonte, Cristina; Onor, Massimo; Zamboni, Roberto; Raspi, Giorgio; D'Ulivo, Alessandro

    2006-10-01

    A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C6H4-COO- (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (-20 degrees C). The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 microg L(-1) for H2S, 13.7 microg L(-1) for CH(3)SH, 17.7 microg L(-1) for C2H5SH and 21.7 microg L(-1) for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 microg L(-1). Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071+/-0.154 microg min(-1) of H2S, giving a recovery of 99.8+/-7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil). PMID:17723725

  9. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrogen sulfide, distn. residues. 721.10445 Section 721.10445 Protection of Environment ENVIRONMENTAL... hydrogen sulfide, distn. residues. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propen-1-ol, reaction products with hydrogen sulfide,...

  10. 40 CFR 721.10445 - 2-Propen-1-ol, reaction products with hydrogen sulfide, distn. residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrogen sulfide, distn. residues. 721.10445 Section 721.10445 Protection of Environment ENVIRONMENTAL... hydrogen sulfide, distn. residues. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propen-1-ol, reaction products with hydrogen sulfide,...

  11. Hydrogen evolution from water through metal sulfide reactions

    NASA Astrophysics Data System (ADS)

    Saha, Arjun; Raghavachari, Krishnan

    2013-11-01

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2SX- (M = Mo and W, X = 4-6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4- isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4- and M2S5- isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (-SH) and a hydroxyl (-OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4- and M2S5- clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6- is highly endothermic with a considerable barrier due to saturation of the local bonding environment.

  12. Estimation of bacterial hydrogen sulfide production in vitro

    PubMed Central

    Basic, Amina; Blomqvist, Susanne; Carln, Anette; Dahln, Gunnar

    2015-01-01

    Oral bacterial hydrogen sulfide (H2S) production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways. PMID:26130377

  13. DETERMINATION OF HYDROGEN SULFIDE IN REFINERY FUEL GASES

    EPA Science Inventory

    Several widely employed test methods for the iodimetric measurement of hydrogen sulfide in refinery fuel gases are shown to suffer from serious thiol interferences. An absorbing solution consisting of 0.16 M cadmium sulfate/sulfuric acid at pH 3.0 is shown to be effective for the...

  14. Hydrogen sulfide release from dairy manure storages containing gypsum bedding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

  15. Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

    DOEpatents

    Basu, Arunabha

    2015-05-05

    A process for recovering sulfur from a hydrogen sulfide-bearing gas utilizes an aqueous reaction medium, a temperature of about 110-150.degree. C., and a high enough pressure to maintain the aqueous reaction medium in a liquid state. The process reduces material and equipment costs and addresses the environmental disadvantages associated with known processes that rely on high boiling point organic solvents.

  16. Biology and therapeutic potential of hydrogen sulfide and hydrogen sulfide-releasing chimeras

    PubMed Central

    Kashfi, Khosrow; Olson, Kenneth R.

    2012-01-01

    Hydrogen sulfide, H2S, is a colorless gas with a strong odor that until recently was only considered to be a toxic environmental pollutant with little or no physiological significance. However, the past few years have demonstrated its role in many biological systems and it is becoming increasingly clear that H2S is likely to join nitric oxide (NO) and carbon monoxide (CO) as a major player in mammalian biology. In this review, we have provided an overview of the chemistry and biology of H2S and have summarized the chemistry and biological activity of some natural and synthetic H2S-donating compounds. The naturally occurring compounds discussed include, garlic, sulforaphane, erucin, and iberin. The synthetic H2S donors reviewed include, GYY4137; cysteine analogs; S-propyl cysteine, S-allyl cysteine, S-propargyl cysteine, and N-acetyl cysteine. Dithiolethione and its NSAID and other chimeras such as, L-DOPA, sildenafil, aspirin, diclofenac, naproxen, ibuprofen, indomethacin, and mesalamine have also been reviewed in detail. The newly reported NOSH-aspirin that releases both NO and H2S has also been discussed. PMID:23103569

  17. Biology and therapeutic potential of hydrogen sulfide and hydrogen sulfide-releasing chimeras.

    PubMed

    Kashfi, Khosrow; Olson, Kenneth R

    2013-03-01

    Hydrogen sulfide, H2S, is a colorless gas with a strong odor that until recently was only considered to be a toxic environmental pollutant with little or no physiological significance. However, the past few years have demonstrated its role in many biological systems and it is becoming increasingly clear that H2S is likely to join nitric oxide (NO) and carbon monoxide (CO) as a major player in mammalian biology. In this review, we have provided an overview of the chemistry and biology of H2S and have summarized the chemistry and biological activity of some natural and synthetic H2S-donating compounds. The naturally occurring compounds discussed include, garlic, sulforaphane, erucin, and iberin. The synthetic H2S donors reviewed include, GYY4137; cysteine analogs; S-propyl cysteine, S-allyl cysteine, S-propargyl cysteine, and N-acetyl cysteine. Dithiolethione and its NSAID and other chimeras such as, L-DOPA, sildenafil, aspirin, diclofenac, naproxen, ibuprofen, indomethacin, and mesalamine have also been reviewed in detail. The newly reported NOSH-aspirin that releases both NO and H2S has also been discussed. PMID:23103569

  18. Epithelial Electrolyte Transport Physiology and the Gasotransmitter Hydrogen Sulfide.

    PubMed

    Pouokam, Ervice; Althaus, Mike

    2016-01-01

    Hydrogen sulfide (H2S) is a well-known environmental chemical threat with an unpleasant smell of rotten eggs. Aside from the established toxic effects of high-dose H2S, research over the past decade revealed that cells endogenously produce small amounts of H2S with physiological functions. H2S has therefore been classified as a "gasotransmitter." A major challenge for cells and tissues is the maintenance of low physiological concentrations of H2S in order to prevent potential toxicity. Epithelia of the respiratory and gastrointestinal tract are especially faced with this problem, since these barriers are predominantly exposed to exogenous H2S from environmental sources or sulfur-metabolising microbiota. In this paper, we review the cellular mechanisms by which epithelial cells maintain physiological, endogenous H2S concentrations. Furthermore, we suggest a concept by which epithelia use their electrolyte and liquid transport machinery as defence mechanisms in order to eliminate exogenous sources for potentially harmful H2S concentrations. PMID:26904165

  19. Epithelial Electrolyte Transport Physiology and the Gasotransmitter Hydrogen Sulfide

    PubMed Central

    Pouokam, Ervice; Althaus, Mike

    2016-01-01

    Hydrogen sulfide (H2S) is a well-known environmental chemical threat with an unpleasant smell of rotten eggs. Aside from the established toxic effects of high-dose H2S, research over the past decade revealed that cells endogenously produce small amounts of H2S with physiological functions. H2S has therefore been classified as a “gasotransmitter.” A major challenge for cells and tissues is the maintenance of low physiological concentrations of H2S in order to prevent potential toxicity. Epithelia of the respiratory and gastrointestinal tract are especially faced with this problem, since these barriers are predominantly exposed to exogenous H2S from environmental sources or sulfur-metabolising microbiota. In this paper, we review the cellular mechanisms by which epithelial cells maintain physiological, endogenous H2S concentrations. Furthermore, we suggest a concept by which epithelia use their electrolyte and liquid transport machinery as defence mechanisms in order to eliminate exogenous sources for potentially harmful H2S concentrations. PMID:26904165

  20. A FRET enzyme-based probe for monitoring hydrogen sulfide.

    PubMed

    Strianese, Maria; Palm, Gottfried J; Milione, Stefano; Khl, Olaf; Hinrichs, Winfried; Pellecchia, Claudio

    2012-11-01

    Fluorescently labeled cobalt peptide deformylase (Co-PDF) can be efficiently used as a fluorescence-resonance-energy-transfer-based sensing device for hydrogen sulfide (H(2)S). The proof of concept of our sensor system is substantiated by spectroscopic, structural, and theoretical results. Monohydrogen sulfide coordination to Co-PDF and Ni-PDF was verified by X-ray crystallography. Density functional theory calculations were performed to gain insight into the characteristics of the coordination adduct between H(2)S and the cobalt cofactor in Co-PDF. PMID:23072298

  1. Endogenously produced hydrogen sulfide is involved in porcine oocyte maturation invitro.

    PubMed

    Nevoral, Jan; almanov, Tereza; Zmostn, Kate?ina; Kott, Tom; Ku?erov-Chrpov, Veronika; Bodart, Jean-Francois; Gelaude, Armance; Prochzka, Radek; Orsk, Maty; ulc, Miloslav; Klein, Pavel; Dvo?kov, Markta; Weingartov, Ivona; Vghov, Aurlia; Hokov, Kristna; Krej?ov, Tereza; Jlek, Frantiek; Petr, Jaroslav

    2015-12-01

    Hydrogen sulfide, one of three known gasotransmitters, is involved in physiological processes, including reproductive functions. Oocyte maturation and surrounding cumulus cell expansion play an essential role in female reproduction and subsequent embryonic development. Although the positive effects of exogenous hydrogen sulfide on maturing oocytes are well known, the role of endogenous hydrogen sulfide, which is physiologically released by enzymes, has not yet been described in oocytes. In this study, we observed the presence of Cystathionine ?-Synthase (CBS), Cystathionine ?-Lyase (CTH) and 3-Mercaptopyruvate Sulfurtransferase (3-MPST), hydrogen sulfide-releasing enzymes, in porcine oocytes. Endogenous hydrogen sulfide production was detected in immature and matured oocytes as well as its requirement for meiotic maturation. Individual hydrogen sulfide-releasing enzymes seem to be capable of substituting for each other in hydrogen sulfide production. However, meiosis suppression by inhibition of all hydrogen sulfide-releasing enzymes is not irreversible and this effect is a result of M-Phase/Maturation Promoting Factor (MPF) and Mitogen-Activated Protein Kinase (MAPK) activity inhibition. Futhermore, cumulus expansion expressed by hyaluronic acid (HA) production is affected by the inhibition of hydrogen sulfide production. Moreover, quality changes of the expanded cumuli are indicated. These results demonstrate hydrogen sulfide involvement in oocyte maturation as well as cumulus expansion. As such, hydrogen sulfide appears to be an important cell messenger during mammalian oocyte meiosis and adequate cumulus expansion. PMID:26456342

  2. Plasma-chemical conversion of hydrogen sulfide into hydrogen and sulfur

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.; Daniels, E.J.

    1993-09-01

    A waste-treatment process that recovers both hydrogen and sulfur from hydrogen-sulfide-contaminated industrial wastes is being developed to replace the Claus technology, which recovers only sulfur. The proposed process is based on research reported in the Soviet technical literature and uses microwave (or radio-frequency) energy to initiate plasma-chemical reactions that dissociate hydrogen sulfide into elemental hydrogen and sulfur. In the plasma-chemical process, the gaseous stream would be purified and separated into streams containing the product hydrogen, hydrogen sulfide for recycle to the plasma reactor, and the process purge containing carbon dioxide and water. Since unconverted hydrogen sulfide is recycled to the plasma reactor, the plasma-chemical process has the potential for sulfur recoveries in excess of 99% without the additional tail-gas clean-up processes associated with the Claus technology. Laboratory experiments with pure hydrogen sulfide have confirmed that conversions of over 90% per pass are possible. Experiments with impurities typical of petroleum refinery and natural gas production acid gases have demonstrated that these impurities are compatible with the plasma dissociation process and do not appear to create new waste-treatment problems. Other experiments show that the cyclonic-flow pattern hypothesized by the Russian theoretical analysis of the plasma-chemical process can substantially decrease energy requirements for hydrogen sulfide dissociation while increasing conversion. This process has several advantages over the current Claus-plus-tail-gas-cleanup technology. The primary advantage is the potential for recovering hydrogen more cheaply than the direct production of hydrogen. The difference could amount to an energy savings of 40 {times} 10{sup 15} to 70 {times} 10{sup 15} J/yr in the refining industry, for an annual savings of $500 million to $1,000 million.

  3. A fatality caused by accidental production of hydrogen sulfide.

    PubMed

    Chaturvedi, A K; Smith, D R; Canfield, D V

    2001-12-01

    A 55-year-old male Caucasian truck driver was dead at the scene after breathing hydrogen sulfide (H(2)S) produced by an accidental transfer of sodium hydrogen sulfide (NaHS) from a tanker truck to a tank containing 4% sulfuric acid (H(2)SO(4)) and iron(II) sulfate (FeSO(4)). Autopsy of the decedent's body revealed pulmonary edema and passive congestion in lungs, spleen, kidneys, and adrenal glands. Postmortem biological samples were analyzed for carbon monoxide, cyanide, ethanol, and drugs. Since a potential exposure to H(2)S was involved, blood was also analyzed for sulfide (S(2-)). The analysis entailed isolating S(2-) from blood as H(2)S using 0.5M H(3)PO(4), trapping the gas in 0.1M NaOH, and determining the electromotive force using a sulfide ion specific electrode. Acetaminophen at a concentration of 14.3 microg/ml was found in blood, and metoprolol was detected in the blood, liver, and kidney samples. The blood S(2-) level was determined to be 1.68 microg/ml. It is concluded that the cause of death was H(2)S poisoning associated with a hazardous material accident in an industrial situation. PMID:11728749

  4. State-of-the-art hydrogen sulfide control for geothermal energy systems: 1979

    SciTech Connect

    Stephens, F.B.; Hill, J.H.; Phelps, P.L. Jr.

    1980-03-01

    Existing state-of-the-art technologies for removal of hydrogen sulfide are discussed along with a comparative assessment of their efficiencies, reliabilities and costs. Other related topics include the characteristics of vapor-dominated and liquid-dominated resources, energy conversion systems, and the sources of hydrogen sulfide emissions. It is indicated that upstream control technologies are preferred over downsteam technologies primarily because upstream removal of hydrogen sulfide inherently controls all downstream emissions including steam-stacking. Two upstream processes for vapor-dominated resources appear promising; the copper sulfate (EIC) process, and the steam converter (Coury) process combined with an off-gas abatement system such as a Stretford unit. For liquid-dominated systems that produce steam, the process where the non-condensible gases are scrubbed with spent geothermal fluid appears to be promising. An efficient downstream technology is the Stretford process for non-condensible gas removal. In this case, partitioning in the surface condenser will determine the overall abatement efficiency. Recommendations for future environmental control technology programs are included.

  5. Hydrogen sulfide determines HNO-induced stimulation of trigeminal afferents.

    PubMed

    Wild, Vanessa; Messlinger, Karl; Fischer, Michael J M

    2015-08-18

    Endogenous NO and hydrogen sulfide form HNO, which causes CGRP release via TRPA1 channel activation in sensory nerves. In the present study, stimulation of intact trigeminal afferent neuron preparations with NO donors, Na2S or both was analyzed by measuring CGRP release as an index of mass activation. Combined stimulation was able to activate all parts of the trigeminal system and acted synergistic compared to stimulation with both substances alone. To investigate the contribution of both substances, we varied their ratio and tracked intracellular calcium in isolated neurons. Our results demonstrate that hydrogen sulfide is the rate-limiting factor for HNO formation. CGRP has a key role in migraine pathophysiology and HNO formation at all sites of the trigeminal system should be considered for this novel means of activation. PMID:26149232

  6. Health assessment document for hydrogen sulfide: review draft

    SciTech Connect

    Ammann, H.M.; Bradow, F.; Fennell, D.; Griffin, R.; Kearney, B.

    1986-08-01

    Hydrogen sulfide is a highly toxic gas which is immediately lethal in concentrations greater than 2000 ppm. The toxic end-point is due to anoxia to brain and heart tissues which results from its interaction with the celluar enzyme cytochrome oxidase. Inhibition of the enzyme halts oxidative metabolism which is the primary energy source for cells. A second toxic end-point is the irritative effect of hydrogen sulfide on mucous membranes, particularly edema at sublethal doses (250 to 500 ppm) in which sufficient exposure occurs before conciousness is lost. Recovered victims of exposure report neurologic symptoms such as headache, fatigue, irritability, vertigo, and loss of libido. Long-term effects are similar to those caused by anoxia due to other toxic agents like CO, and probably are not due to specific H/sub 2/S effects. H/sub 2/S is not a cumulative poison. No mutagenic, carcinogenic, reproductive, or teratogenic effects have been reported in the literature.

  7. Catalytic oxidation of hydrogen sulfide to sulfur on vanadium antimonate

    SciTech Connect

    Li, K.T.; Shyu, N.S.

    1997-05-01

    Conversion of H{sub 2}S to elemental sulfur is presently considered the most effective means to remove the pollutant from petroleum refinery gases and from natural gases. The catalytic oxidation of hydrogen sulfide to sulfur on three vanadium antimonate catalysts (with bulk V/Sb atomic ratio at 5/1, 1/1, and 1/5) was studied with a flow reactor in the temperature range of 180--280 C. Strong synergistic phenomena in catalytic activity and selectivity were observed for the vanadium antimonate catalysts. The catalyst with equal vanadium atoms and antimony atoms (abbreviated as VSB11 catalyst) was found to be the most effective, and the X-ray diffractometric data showed that the major phase present in the VSB11 catalyst was rutile VSbO{sub 4} which contained antimony in the oxidized state (Sb{sup 5+}) and vanadium in the reduced state. X-ray photoelectron spectroscopic data suggested that both surface vanadium sites and surface antimony sites were in the reduced state after the oxidation of hydrogen sulfide. Under the condition of dilute H{sub 2}S and O{sub 2}/H{sub 2}S molar ratio {ge}1, the oxidation rate on the VSB11 catalyst was determined to be first order in hydrogen sulfide and zero order in oxygen, which suggested that the reaction followed the redox mechanism and the rate-limiting step was the reduction of the oxidized catalyst (probably VSbO{sub 4}) by hydrogen sulfide.

  8. Hydrogen evolution from water through metal sulfide reactions

    SciTech Connect

    Saha, Arjun; Raghavachari, Krishnan

    2013-11-28

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M{sub 2}S{sub X}{sup −} (M = Mo and W, X = 4–6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo{sub 2}S{sub 4}{sup −} isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W{sub 2}S{sub 4}{sup −} and M{sub 2}S{sub 5}{sup −} isomers. In all the lowest energy H{sub 2} elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H{sub 2} elimination step involve a thiol (–SH) and a hydroxyl (–OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M{sub 2}S{sub 4}{sup −} and M{sub 2}S{sub 5}{sup −} clusters with water to liberate H{sub 2} are exothermic and involve modest free energy barriers. However, the reaction of water with M{sub 2}S{sub 6}{sup −} is highly endothermic with a considerable barrier due to saturation of the local bonding environment.

  9. Hydrogen sulfide inhalation ameliorates allergen induced airway hypereactivity by modulating mast cell activation.

    PubMed

    Roviezzo, Fiorentina; Bertolino, Antonio; Sorrentino, Rosalinda; Terlizzi, Michela; Matteis, Maria; Calderone, Vincenzo; Mattera, Valentina; Martelli, Alma; Spaziano, Giuseppe; Pinto, Aldo; D'Agostino, Bruno; Cirino, Giuseppe

    2015-10-01

    Compelling evidence suggests that hydrogen sulfide represents an important gaseous transmitter in the mammalian respiratory system. In the present study, we have evaluated the role of mast cells in hydrogen sulfide-induced effects on airways in a mouse model of asthma. Mice were sensitized to ovalbumin and received aerosol of a hydrogen sulfide donor (NaHS; 100 ppm) starting at day 7 after ovalbumin challenge. Exposure to hydrogen sulfide abrogated ovalbumin-induced bronchial hypereactivity as well as the increase in lung resistance. Concomitantly, hydrogen sulfide prevented mast cell activity as well as FGF-2 and IL-13 upregulation. Conversely, pulmonary inflammation and the increase in plasmatic IgE levels were not affected by hydrogen sulfide. A lack of hydrogen sulfide effects in mast cell deficient mice occurred. Primary fibroblasts harvested from ovalbumin-sensitized mice showed an increased proliferation rate that was inhibited by hydrogen sulfide aerosol. Furthermore, ovalbumin-induced transdifferentiation of pulmonary fibroblasts into myofibroblasts was reversed. Finally, hydrogen sulfide did abrogate in vitro the degranulation of the mast cell-like RBL-2H3 cell line. Similarly to the in vivo experiments the inhibitory effect was present only when the cells were activated by antigen exposure. In conclusion, inhaled hydrogen sulfide improves lung function and inhibits bronchial hyper-reactivity by modulating mast cells and in turn fibroblast activation. PMID:26241177

  10. Solubility of hydrogen sulfide in aqueous solutions of the single salts sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride at temperatures from 313 to 393 K and total pressures up to 10 MPa

    SciTech Connect

    Xia, J.; Kamps, A.P.S.; Rumpf, B.; Maurer, G.

    2000-04-01

    New experimental results for the solubility of hydrogen sulfide in aqueous solutions of the single salts sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride at temperatures from 313 to 393 K and total pressures up to 10 MPa are reported. As in the salt-free system, a second-hydrogen sulfide-rich--liquid phase is observed at high hydrogen sulfide concentrations. A model to describe the phase equilibrium is presented. Calculations are compared to the new experimental data.

  11. High temperature solar thermochemical processing - Hydrogen and sulfur from hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Noring, J. E.; Fletcher, E. A.

    1982-08-01

    Sunlight, concentrated to high intensities, has a rarely recognized potential for adding process heat to reactors at high temperatures. Hydrogen sulfide is a by-product of the sweetening of fossil fuels. In this paper, by way of example, the production of hydrogen and sulfur from hydrogen sulfide is used as a device for showing how solar processing might be considered as a successor to a currently used industrial process, the Claus process. It is concluded that this and other processes should be explored as means of using as well as storing solar energy.

  12. Decomposition of Hydrogen Sulfide in a Dielectric-Barrier Discharge

    NASA Astrophysics Data System (ADS)

    Kogelschatz, Ulrich; Killer, Eric; Eliasson, Baldur

    1999-10-01

    Hydrogen sulfide is not only an unwanted compound that has to be efficiently removed in many industrial processes but it is also an abundant source for potentially cheap hydrogen. Many natural gas reserves contain large amounts of hydrogen sulfide mixed with the natural gas. In the past plasma processing of H_2S has been extensively investigated in low-pressure microwave discharges. Some laboratory experiments have also been performed in dielectric-barrier discharges (DBDs). We report on complete decomposition of atmospheric pressure H_2S into hydrogen and solid sulfur in a small laboratory through-flow DBD reactor made of two coaxial cylindrical quartz tubes with external coaxial electrodes. The discharge is confined to an annular gap of 2 mm radial width and 110 mm length. It can be observed through a wire mesh electrode. In some of the experiments helium was used as a carrier gas. The concentrations of H2 and H_2S were measured with a gas chromatograph equipped with a PoraPlot Q column and a molecular sieve column. The dielectric-barrier discharge was operated in the frequency range 20-25 kHz or in the range 180-215 kHz. The amount of hydrogen generated was related to the amount of energy put into the discharge.

  13. Atomic layer deposition of aluminum sulfide thin films using trimethylaluminum and hydrogen sulfide

    SciTech Connect

    Sinha, Soumyadeep; Sarkar, Shaibal K.; Mahuli, Neha

    2015-01-15

    Sequential exposures of trimethylaluminum and hydrogen sulfide are used to deposit aluminum sulfide thin films by atomic layer deposition (ALD) in the temperature ranging from 100 to 200 °C. Growth rate of 1.3 Å per ALD cycle is achieved by in-situ quartz crystal microbalance measurements. It is found that the growth rate per ALD cycle is highly dependent on the purging time between the two precursors. Increased purge time results in higher growth rate. Surface limited chemistry during each ALD half cycle is studied by in-situ Fourier transformed infrared vibration spectroscopy. Time of flight secondary ion-mass spectroscopy measurement is used to confirm elemental composition of the deposited films.

  14. Liquid Hydrogen Absorber for MICE

    SciTech Connect

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  15. Hydrogen Sulfide-Mechanisms of Toxicity and Development of an Antidote.

    PubMed

    Jiang, Jingjing; Chan, Adriano; Ali, Sameh; Saha, Arindam; Haushalter, Kristofer J; Lam, Wai-Ling Macrina; Glasheen, Megan; Parker, James; Brenner, Matthew; Mahon, Sari B; Patel, Hemal H; Ambasudhan, Rajesh; Lipton, Stuart A; Pilz, Renate B; Boss, Gerry R

    2016-01-01

    Hydrogen sulfide is a highly toxic gas-second only to carbon monoxide as a cause of inhalational deaths. Its mechanism of toxicity is only partially known, and no specific therapy exists for sulfide poisoning. We show in several cell types, including human inducible pluripotent stem cell (hiPSC)-derived neurons, that sulfide inhibited complex IV of the mitochondrial respiratory chain and induced apoptosis. Sulfide increased hydroxyl radical production in isolated mouse heart mitochondria and F2-isoprostanes in brains and hearts of mice. The vitamin B12 analog cobinamide reversed the cellular toxicity of sulfide, and rescued Drosophila melanogaster and mice from lethal exposures of hydrogen sulfide gas. Cobinamide worked through two distinct mechanisms: direct reversal of complex IV inhibition and neutralization of sulfide-generated reactive oxygen species. We conclude that sulfide produces a high degree of oxidative stress in cells and tissues, and that cobinamide has promise as a first specific treatment for sulfide poisoning. PMID:26877209

  16. Twenty-foot fall averts fatality from massive hydrogen sulfide exposure.

    PubMed

    Gabbay, D S; De Roos, F; Perrone, J

    2001-02-01

    Hydrogen sulfide is a colorless irritant and asphyxiant gas with a noxious odor of "rotten eggs." Acute hydrogen sulfide exposure may cause, depending on the level and duration of toxicity, symptoms ranging from mild mucous membrane irritation to permanent neurologic impairment and cardiopulmonary arrest. We present a case of an oil refinery worker exposed to a typically fatal concentration of hydrogen sulfide gas (>1000 ppm) while working on top of a 20-foot ladder. The "knockdown" effect of exposure to high concentrations of hydrogen sulfide caused him to lose consciousness and fall from the top of the ladder. He was transported to the Emergency Department as a major trauma victim. Ironically, this 20-foot fall saved his life and possibly those of the rescuers by immediately removing him from the source of the hydrogen sulfide. Treatment of hazardous materials incidents and the pathophysiology and treatment options for hydrogen sulfide poisoning are discussed. PMID:11207408

  17. Modeling of hydrogen sulfide oxidation in concrete corrosion products from sewer pipes.

    PubMed

    Jensen, Henriette Stokbro; Nielsen, Asbjrn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2009-04-01

    Abiotic and biotic oxidation of hydrogen sulfide related to concrete corrosion was studied in corrosion products originating from a sewer manhole. The concrete corrosion products were suspended in an acidic solution, mimicking the conditions in the pore water of corroded concrete. The removal of hydrogen sulfide and dissolved oxygen was measured in parallel in the suspension, upon which the suspension was sterilized and the measurement repeated. The results revealed the biotic oxidation to be fast compared with the abiotic oxidation. The stoichiometry of the hydrogen sulfide oxidation was evaluated using the ratio between oxygen and hydrogen sulfide uptake. The ratio for the biotic oxidation pointed in the direction of elemental sulfur being formed as an intermediate in the oxidation of hydrogen sulfide to sulfuric acid. The experimental results were applied to suggest a hypothesis and a mathematical model describing the hydrogen sulfide oxidation pathway in a matrix of corroded concrete. PMID:19445325

  18. Modelling studies for hydrogen sulfide fuelled SOFCs

    NASA Astrophysics Data System (ADS)

    Monder, Dayadeep

    Solid oxide fuel cells (SOFCs) are high temperature, ceramic electrolyte fuel cells. Unlike most other fuel cells, which require high purity hydrogen to generate electricity, SOFCs can utilize a variety of fuels, including hydrocarbons. This work presents modelling and experimental work performed on a laboratory scale H2S-fuelled SOFC equipped with a novel anode that can electro-oxidize H2S into water vapour and sulphur. Using H2S, a toxic by-product of the fossil fuel industry, such a fuel cell can potentially generate useful electrical energy while disposing off this toxic pollutant on site. In this dissertation, I develop a hierarchy of first principles models for H2S solid oxide fuel cells. The models developed fall into the following four categories: (i) detailed models of H2S electrochemistry; (ii) isothermal 1-D and 2-D transport and reaction models of the 'near cell' region that do not take H2S dissociation into account; (iii) chemical thermodynamics models of H2S dissociation in the fuel channel that also calculate the open circuit voltage (OCV) of the SOFC for the different possible fuels; (iv) fully coupled 2-D transport and reaction models for the complete fuel cell assembly that include heat transfer and H2S dissociation kinetics. The models in the final category above include all the physics and chemistry in a working H2S SOFC by including all transport phenomena, thermodynamically consistent kinetics of the chemical/electrochemical reactions, along with the electrical potential distribution in the fuel cell assembly. These multiphysics models are then used to estimate unknown electrochemical parameters, and to understand and explain experimental data from H2S SOFCs. Experimental results from H2S SOFCs exhibit characteristics which are either poorly explained in current literature or not explained at all e.g., an unusual dependence of cell performance on fuel composition. To support my modelling effort, I and a colleague conducted experiments where the composition and flow rates were varied for both the fuel and oxidant streams to analyze their effect on fuel cell performance. I present these experimental results and demonstrate the importance of thermodynamic and multiphysics modelling in understanding these results.

  19. Corrosion of concrete sewers--the kinetics of hydrogen sulfide oxidation.

    PubMed

    Vollertsen, Jes; Nielsen, Asbjrn Haaning; Jensen, Henriette Stokbro; Wium-Andersen, Tove; Hvitved-Jacobsen, Thorkild

    2008-05-01

    Hydrogen sulfide absorption and oxidation by corroding concrete surfaces was quantified in a test rig consisting of 6 concrete pipes operated under sewer conditions. The test rig was placed in an underground sewer monitoring station with access to fresh wastewater. Hydrogen sulfide gas was injected into the pipe every 2nd hour to peak concentrations around 1000 ppm. After some months of operation, the hydrogen sulfide became rapidly oxidized by the corroding concrete surfaces. At hydrogen sulfide concentrations of 1000 ppm, oxidation rates as high as 1 mg S m(-2) s(-1) were observed. The oxidation process followed simple nth order kinetics with a process order of 0.45-0.75. Extrapolating the results to gravity sewer systems showed that hydrogen sulfide oxidation by corroding concrete is a fast process compared to the release of hydrogen sulfide from the bulk water, resulting in low gas concentrations compared with equilibrium. Balancing hydrogen sulfide release with hydrogen sulfide oxidation at steady state conditions demonstrated that significant corrosion rates--several millimeters of concrete per year--can potentially occur at hydrogen sulfide gas phase concentrations well below 5-10 ppm. The results obtained in the study advances the knowledge on prediction of sewer concrete corrosion and the extent of odor problems. PMID:18281080

  20. Bioluminescence Probe for Detecting Hydrogen Sulfide in Vivo.

    PubMed

    Ke, Bowen; Wu, Wenxiao; Liu, Wei; Liang, Hong; Gong, Deying; Hu, Xiaotong; Li, Minyong

    2016-01-01

    Considering that hydrogen sulfide (H2S) is an endogenous signaling molecule involved in numerous biological processes, a method for monitoring H2S as a powerful tool for investigating its complicated functions and mechanisms is urgently demanded. Herein, a bioluminescent turn-on probe was reported based on caged strategy for the detection of H2S in vitro and in vivo. This probe will help us understand the intricate contribution of H2S to a variety of physiological and pathological processes. PMID:26634959

  1. Micellar-mediated extractive spectrophotometric determination of hydrogen sulfide/sulfide through Prussian Blue reaction: application to environmental samples.

    PubMed

    Pandurangappa, Malingappa; Samrat, Devaramani

    2010-01-01

    A sensitive surfactant-mediated extractive spectrophotometric method has been developed, based on the reaction of ferric iron with sulfide to form ferrous iron and its subsequent reaction with ferricyanide to form Prussian Blue, to quantify trace levels of hydrogen sulfide/sulfide in environmental samples. The method obeys Beer's law in the concentration range 2-10 microg of sulfide in 25 mL of aqueous phase with molar absorptivity (epsilon) of 3.92 x 10(4) L mol(-1) cm(-1). The colored species has been extracted into isoamyl acetate in the presence of a cationic surfactant i.e. cetylpyridinium chloride, to enhance the sensitivity of the method with epsilon value 5.2 x 10(4) L mol(-1) cm(-1). The relative standard deviation has been found to be 0.69% for 10 determinations at 4 microg of sulfide and the limit of detection was 0.009 microg mL(-1). The interference from common anions and cations has been studied. The proposed method has been applied to the determination of residual hydrogen sulfide in the laboratory fume hood as well as ambient atmospheric hydrogen sulfide in the vicinity of open sewer lines after fixing the analyte in ionic form using suitable trapping medium. PMID:20065592

  2. Quantum corrections to induced light scattering and the second virial coefficient of water and hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    De Santis, A.; Gregori, A.

    1989-07-01

    Some model pair potentials of liquid water and hydrogen sulfide have been used for computing second virial coefficients, lowdensity values of depolarized light scattering due to the dipole-induced-dipole (DID) mechanism, mean-square torques and mean-square forces versus temperature. The second virial coefficient and depolarized scattering were corrected to account for quantum effects, which are found to be relevant in the case of water. The "MCY" water pair potential gives values of the second virial coefficient in good agreement with experiment, while computed and experimental values of the DID intensity disagree significantly. Possible reasons for this discrepancy are discussed.

  3. Dynamic flux chamber measurements of hydrogen sulfide emission rate from a quiescent surface - A computational evaluation.

    PubMed

    Prata, Ademir A; Santos, Jane M; Beghi, Sandra P; Fernandes, Isabella F; Vom Marttens, Lya L C; Pereira Neto, Leovegildo I; Martins, Ramon S; Reis, Neyval C; Stuetz, Richard M

    2016-03-01

    Enclosure devices have been studied and used for research purposes and practical applications in order to measure the emission rate of odorous pollutants from quiescent liquid surfaces to atmosphere. However, important questions remain about the interference of these measuring devices on the actual emission rate. The main concern regarding the use of a flux chamber is the fact that odorous compounds can accumulate into the chamber and yield gas-phase concentration increase inside the equipment, which causes a reduction of the emission rate during the measurement and thus gives an inaccurate local emission rate. Furthermore, the fluid flow inside the chamber does not reproduce the atmospheric boundary layer flow. This study applied the Computational Fluid Dynamics (CFD) technique in order to investigate the influence of the fluid flow features inside a flux chamber on the measured hydrogen sulfide emission rate at quiescent liquid surfaces. The flux chamber design and operational conditions are those supported by the United States Environmental Protection Agency (US EPA). The results show that the US EPA flux chamber presents a fairly well mixed air phase. However, a trend to stagnation and hydrogen sulfide accumulation near chamber walls was detected in the computational simulation, which also indicated that the positioning of the sampling tube in relation to the inlet orifices may lead to deviations in the measurement results. CFD results showed that the wall shear and concentration gradients spatially vary at the gas-liquid interface, and friction velocity inside the chamber does not match typical values of atmospheric flow. PMID:26741548

  4. Catalysts for the selective oxidation of hydrogen sulfide to sulfur

    DOEpatents

    Srinivas, Girish; Bai, Chuansheng

    2000-08-08

    This invention provides catalysts for the oxidation of hydrogen sulfide. In particular, the invention provides catalysts for the partial oxidation of hydrogen sulfide to elemental sulfur and water. The catalytically active component of the catalyst comprises a mixture of metal oxides containing titanium oxide and one or more metal oxides which can be selected from the group of metal oxides or mixtures of metal oxides of transition metals or lanthanide metals. Preferred metal oxides for combination with TiO.sub.2 in the catalysts of this invention include oxides of V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Tc, Ru, Rh, Hf, Ta, W, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Catalysts which comprise a homogeneous mixture of titanium oxide and niobium (Nb) oxide are also provided. A preferred method for preparing the precursor homogenous mixture of metal hydroxides is by coprecipitation of titanium hydroxide with one or more other selected metal hydroxides. Catalysts of this invention have improved activity and/or selectivity for elemental sulfur production. Further improvements of activity and/or selectivity can be obtained by introducing relatively low amounts (up to about 5 mol %)of a promoter metal oxide (preferably of metals other than titanium and that of the selected second metal oxide) into the homogeneous metal/titanium oxide catalysts of this invention.

  5. Seasonal and influent characteristic effects on hydrogen sulfide generation at a water reclamation plant.

    PubMed

    Zhang, Yanming; Moschandreas, Demetrios; Pagilla, Krishna

    2014-01-01

    Correlations between sulfide generation and seasonal influent wastewater characteristics were identified based on a long-term monitoring program in summer and winter at a water reclamation plant. During summer, the emission rates of hydrogen sulfide (H2S) from the liquid treatment processes increased substantially compared to those during winter due to the increased wastewater temperature. The open tanks/clarifiers were the least significant H2S emission contributors throughout the year. For solids-handling processes, the H2S emission rates did not change during the year due to similar sludge characteristics in the different seasons. The fate of sulfide in liquid treatment processes was investigated as an alternative to estimation of H2S emissions. H2S emission from the wet well and screens was proven to be robustly associated with the wastewater temperature, flow rate, 5-day biochemical oxygen demand and total Kjeldahl nitrogen levels. However, the correlation between influent parameters and H2S emission from aerated grit chambers was not statistically significant. PMID:25353935

  6. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers.

    PubMed

    Jensen, Henriette Stokbro; Lens, Piet N L; Nielsen, Jeppe L; Bester, Kai; Nielsen, Asbjrn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2011-05-30

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria, were suspended in aqueous solution at pH similar to that of corroded concrete. Hydrogen sulfide was supplied to the reactor to provide the source of reduced sulfur. The removal of hydrogen sulfide and oxygen was monitored. The utilization rates of both hydrogen sulfide and oxygen suggested exponential bacterial growth with median growth rates of 1.25 d(-1) and 1.33 d(-1) as determined from the utilization rates of hydrogen sulfide and oxygen, respectively. Elemental sulfur was found to be the immediate product of the hydrogen sulfide oxidation. When exponential growth had been achieved, the addition of hydrogen sulfide was terminated leading to elemental sulfur oxidation. The ratio of consumed sulfur to consumed oxygen suggested that sulfuric acid was the ultimate oxidation product. To the knowledge of the authors, this is the first study to determine the growth rate of bacteria involved in concrete corrosion with hydrogen sulfide as source of reduced sulfur. PMID:21440988

  7. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Contents of Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must accompany the...

  8. Survival of hydrogen sulfide oxidizing bacteria on corroded concrete surfaces of sewer systems.

    PubMed

    Jensen, H S; Nielsen, A H; Hvitved-Jacobsen, T; Vollertsen, J

    2008-01-01

    The activity of hydrogen sulfide oxidizing bacteria within corroded concrete from a sewer manhole was investigated. The bacteria were exposed to hydrogen sulfide starvation for up till 18 months, upon which their hydrogen sulfide oxidizing activity was measured. It was tested whether the observed reduction in biological activity was caused by a biological lag phase or by decay of the bacteria. The results showed that the bacterial activity declined with approximately 40% pr. month during the first two months of hydrogen sulfide starvation. After 2-3 months of starvation, the activity stabilized. Even after 6 months of starvation, exposure to hydrogen sulfide for 6 hours a day on three successive days could restore the bacteriological activity to about 80% of the initial activity. After 12 months of starvation, the activity could, however, not be restored, and after 18 months the biological activity approached zero. The long-term survival aspect of concrete corroding bacteria has implications for predicting hydrogen sulfide corrosion in sewer systems subject to irregular hydrogen sulfide loadings, e.g. as they occur in temperate climates where hydrogen sulfide often is a summer-problem only. PMID:18547922

  9. A STUDY TO EVALUATE CARBON MONOXIDE AND HYDROGEN SULFIDE CONTINUOUS EMISSION MONITORS AT AN OIL REFINERY

    EPA Science Inventory

    An eleven month field evaluation was done on five hydrogen sulfide and four carbon monoxide monitors located at an oil refinery. The hydrogen sulfide monitors sampled a fuel gas feed line and the carbon monoxide monitors sampled the emissions from a fluid cat cracker (FCC). Two o...

  10. An intercomparison of aircraft instrumentation for tropospheric measurements of carbonyl sulfide, hydrogen sulfide, and carbon disulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Davis, Douglas D.; Thornton, Donald C.; Johnson, James E.; Bandy, Alan R.; Saltzman, Eric S.; Andreae, Meinrat O.; Barrick, John D.

    1993-01-01

    This paper reports results of NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements for carbonyl sulfide (COS), hydrogen sulfide (H2S), and carbon disulfide (CS2) were intercompared. Instrumentation included a gas chromatograph using flame photometric detection (COS, H2S, and CS2), a gas chromatograph using mass spectrometric detection (COS) and CS2), a gas chromatograph using fluorination and subsequent SF6 detection via electron capture (COS and CS2), and the Natusch technique (H2S). The measurements were made over the Atlantic Ocean east of North and South America during flights from NASA's Wallops Flight Center, Virginia, and Natal, Brazil, in August/September 1989. Most of the intercomparisons for H2S and CS2 were at mixing ratios less than 25 pptv and less than 10 pptv, respectively, with a maximum mixing ratio of about 100 pptv and 50 pptv, respectively. Carbonyl sulfide intercomparisons were at mixing ratios between 400 and 600 pptv. Measurements were intercompared from data bases constructed from time periods of simultaneous or overlapping measurements. Agreement among the COS techniques averaged about 5%, and individual measurements were generally within 10%. For H2S and at mixing ratio greater than 25 pptv, the instruments agreed on average to about 15%. At mixing ratios less than 25 pptv the agreement was about 5 pptv. For CS2 (mixing ratios less than 50 pptv), two techniques agreed on average to about 4 pptv, and the third exhibited a bias (relative to the other two) that varied in the range of 3-7 pptv. CS2 mixing ratios over the ocean east of Natal as measured by the gas chromatograph-mass spectrometer technique were only a few pptv and were below the detection limits of the other two techniques. The CITE 3 data are used to estimate the current uncertainty associated with aircraft measurements of COS, H2S, and CS2 in the remote troposphere.

  11. Factors controlling the reactivity of hydrogen sulfide with hemeproteins

    PubMed Central

    Pietri, Ruth; Lewis, Ariel; Len, Ruth G.; Casabona, Gullermina; Kiger, Laurent; Yeh, Syun-Ru; Fernandez-Alberti, Sebastian; Marden, Michael C.; Cadilla, Carmen L.; Lpez-Garriga, Juan

    2009-01-01

    Hemoglobin I (HbI) from the clam Lucina pectinata is an intriguing hemeprotein that binds and transports H2S to sulfide-oxidizing chemoautotrophic bacteria to maintain a symbiotic relationship and to protect the mollusk from H2S toxicity. Single point mutations at E7, B10 and E11 positions were introduced in the HbI heme pocket to define the reactivity of sulfide with hemeproteins. The functional and structural properties of mutant and wild type recombinant proteins were first evaluated using the well-known ferrous CO and O2 derivatives. The effects of these mutations on the ferric environment were then studied in the metaquo and hydrogen sulfide derivatives. The results obtained with the ferrous HbI mutants show that all the E7 substitutions and the PheB10Tyr mutation influence directly CO and O2 binding and stability while the B10 and E11 substitutions induce distal structural rearrangements that affect ligand entry and escape indirectly. For the metaquo-GlnE7His, PheB10Val, PheB10Leu and the E11 variants, two individual distal structures are suggested, one of which is associated with H-bonding interactions between the E7 residues and the bound water. Similar H-bonding interactions are invoked for these HbI-H2S mutant derivatives and the rHbI, altering in turn sulfide reactivity within these protein samples. This is evident in the resonance Raman spectra of these HbI-H2S complexes, which show reduction of heme iron as judged by the appearance of the ?4 oxidation state marker at 1356 cm?1, indicative of heme-FeII species. This reduction process depends strongly on distal mutations showing faster reduction for those HbI mutants exhibiting strongest H-bonding interactions. Overall, the results presented here show that: a. H2S association is regulated by steric constraints; b. H2S release is controlled by two competing reactions involving simple sulfide dissociation and heme reduction; c. at high H2S concentrations, reduction of the ferric center dominates; d. reduction of the heme is also enhanced in those HbI mutants having polar distal environments. PMID:19368335

  12. Carbonyl sulfide removal with compost and wood chip biofilters, and in the presence of hydrogen sulfide.

    PubMed

    Sattler, Melanie L; Garrepalli, Divya R; Nawal, Chandraprakash S

    2009-12-01

    Carbonyl sulfide (COS) is an odor-causing compound and hazardous air pollutant emitted frequently from wastewater treatment facilities and chemical and primary metals industries. This study examined the effectiveness of biofiltration in removing COS. Specific objectives were to compare COS removal efficiency for various biofilter media; to determine whether hydrogen sulfide (H2S), which is frequently produced along with COS under anaerobic conditions, adversely impacts COS removal; and to determine the maximum elimination capacity of COS for use in biofilter design. Three laboratory-scale polyvinyl chloride biofilter columns were filled with up to 28 in. of biofilter media (aged compost, fresh compost, wood chips, or a compost/wood chip mixture). Inlet COS ranged from 5 to 46 parts per million (ppm) (0.10-9.0 g/m3 hr). Compost and the compost/wood chip mixture produced higher COS removal efficiencies than wood chips alone. The compost and compost/wood chip mixture had a shorter stabilization times compared with wood chips alone. Fresh versus aged compost did not impact COS removal efficiency. The presence of H2S did not adversely impact COS removal for the concentration ratios tested. The maximum elimination capacity is at least 9 g/m3 hr for COS with compost media. PMID:20066911

  13. Mitochondrial Sulfide Quinone Oxidoreductase Prevents Activation of the Unfolded Protein Response in Hydrogen Sulfide.

    PubMed

    Horsman, Joseph W; Miller, Dana L

    2016-03-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous molecule with important roles in cellular signaling. In mammals, exogenous H2S improves survival of ischemia/reperfusion. We have previously shown that exposure to H2S increases the lifespan and thermotolerance in Caenorhabditis elegans, and improves protein homeostasis in low oxygen. The mitochondrial SQRD-1 (sulfide quinone oxidoreductase) protein is a highly conserved enzyme involved in H2S metabolism. SQRD-1 is generally considered important to detoxify H2S. Here, we show that SQRD-1 is also required to maintain protein translation in H2S. In sqrd-1 mutant animals, exposure to H2S leads to phosphorylation of eIF2? and inhibition of protein synthesis. In contrast, global protein translation is not altered in wild-type animals exposed to lethally high H2S or in hif-1(ia04) mutants that die when exposed to low H2S. We demonstrate that both gcn-2 and pek-1 kinases are involved in the H2S-induced phosphorylation of eIF2?. Both ER and mitochondrial stress responses are activated in sqrd-1 mutant animals exposed to H2S, but not in wild-type animals. We speculate that SQRD-1 activity in H2S may coordinate proteostasis responses in multiple cellular compartments. PMID:26677221

  14. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs.

    PubMed

    Klatt, Judith M; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-09-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2 S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2 S: (i) H2 S accelerated the recovery of photosynthesis after prolonged exposure to darkness and anoxia. We suggest that this is possibly due to regulatory effects of H2 S on photosystem I components and/or on the Calvin cycle. (ii) H2 S concentrations of up to 210??M temporarily enhanced the photosynthetic rates at low irradiance. Modelling showed that this enhancement is plausibly based on changes in the light-harvesting efficiency. (iii) Above a certain light-dependent concentration threshold H2 S also acted as an inhibitor. Intriguingly, this inhibition was not instant but occurred only after a specific time interval that decreased with increasing light intensity. That photosynthesis is most sensitive to inhibition at high light intensities suggests that H2 S inactivates an intermediate of the oxygen evolving complex that accumulates with increasing light intensity. We discuss the implications of these three effects of H2 S in the context of cyanobacterial photosynthesis under conditions with diurnally fluctuating light and H2 S concentrations, such as those occurring in microbial mats and biofilms. PMID:25630511

  15. Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

    1991-01-01

    Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

  16. Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

    PubMed

    Bailey, T Spencer; Zakharov, Lev N; Pluth, Michael D

    2014-07-30

    Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool. PMID:25010540

  17. The determination of hydrogen sulfide and total sulfur

    SciTech Connect

    Vincent, A.

    1995-12-01

    Producers, processors, pipelines and distribution companies measure both hydrogen sulfide (H2S) and total sulfur for compliance with purchase contracts, which generally contain sulfur quality clauses relating to those two parameters. A quarter grain of H2S per one hundred standard cubic feet (0.25 gr H2S/100 SCF) and one grain of total sulfur (1 gr S/100 SCF) are common contract limits. To ensure that both buyer and seller are dealing with gas within these limits, it is common to monitor both parameters, as well as others, on both sides of the custody transfer point. More often, sulfur monitoring entails measuring total sulfur, mercaptans, and sulfides to assure the gas is odorized at the desired level. Odorant is a combination of mercaptans and sulfides added to the gas to alert users of any leaks. Odorization at the proper level is important since over-odorization is an waste of costly chemicals resulting in excess leak calls, and under-odorization is a safety hazard for the customer which in the worst case could result in an explosion with great personal injury and property damage. Odorant monitoring should also be used in conjunction with olfactory readings as an archival record in the event of litigation. There are several means of measuring these parameters, using either manual methods or instrument techniques. The manual methods involve wet chemistry, including collecting the desired sulfur compounds in an absorbing solution and then titrating the solution with a second reactive solution of known concentration. These methods are described in detail in ASTM and the Gas Processors. In this treatment we will discuss only the instrumental means, the most common of which are gas chromatography, lead acetate tape methods. and electrolytic titration.

  18. High temperature hydrogen sulfide removal with tin oxide

    SciTech Connect

    Karpuk, M.E.; Copeland, R.J.; Feinberg, D.; Wickham, D.; Windecker, B.; Yu, J.

    1993-09-01

    The system is based on the absorption of hydrogen sulfide (H{sub 2}S) by stannic (tin) oxide. Two sorbents are required, the first sorbent is tin oxide and the second sorbent is a zinc oxide based material (i.e., zinc ferrite or zinc titanate) which is regenerated by air producing SO{sub 2}. TDA`s process carries out a modified Claus reaction to reduce the SO{sub 2} from the second sorbent generation to elemental sulfur. In this case the sulfided stannic oxide forms stannous sulfide (SnS) which reduces the SO{sub 2}. The absorption by SnO{sub 2} could remove over 90% of the H{sub 2}S from typical coal gas streams, but we use zinc ferrite (or zinc titanate), (a) to reduce H{sub 2}S to less than 20 ppM and (b) as a source of SO{sub 2} in regeneration. Due to stoichiometry of regeneration we want to remove half of the H{sub 2}S by SnO{sub 2} and the remainder by the second sorbent. The reactions with stannic oxide minimize the heat released during H{sub 2}S removal and regeneration. The absorption by SnO{sub 2} is slightly endothermic and cools the gas stream by less that 5{degrees}F (2.8{degrees}C) during absorption. Regeneration with SO{sub 2} is exothermic but releases only 11% of the heat that is liberated in regenerating the ZnO. For a nominal 6.5:1 steam to air the regeneration of ZnO increases the temperature by {approx_equal}400{degrees}F. The regeneration of SnO{sub 2} increases the temperature by less than 50{degrees}F (28{degrees}C) in the same gas flow.

  19. Analytical Measurement of Discrete Hydrogen Sulfide Pools in Biological Specimens

    PubMed Central

    Shen, Xinggui; Peter, Elvis A.; Bir, Shyamal; Wang, Rui; Kevil, Christopher G.

    2015-01-01

    Hydrogen sulfide (H2S) is a ubiquitous gaseous signaling molecule that plays a vital role in numerous cellular functions and has becomethefocus of many research endeavors including pharmaco-therapeutic manipulation. Amongst the challenges facing the field is the accurate measurement of biologically active H2S. We have recently reported that the typically used methylene blue method and its associated results are invalid and do not measure bonafide H2S. The complexity of analytical H2S measurement reflects the fact that hydrogen sulfide is a volatile gas and exists in the body in different forms, including a free form, an acid labile pool and as bound sulfane sulfur. Here we describe a new protocol to discretely measure specific H2S pools using the monobromobimane method coupled with RP-HPLC. This new protocol involves selective liberation, trapping and derivatization of H2S. Acid-labile H2S is released by incubating the sample in an acidic solution (pH 2.6) of 100 mM phosphate buffer with 0.1 mM DTPA, in an enclosed system to contain volatilized H2S. Volatilized H2S is then trapped in 100 mM Tris-HCl (pH 9.5, 0.1 mM DTPA) and then reacted with excess monobromobimane. In a separate aliquot, the contribution of bound sulfane sulfur pool was measured by incubating the sample with 1 mM TCEP(Tris(2-carboxyethyl)phosphine hydrochloride), a reducing agent to reduce disulfide bonds, in 100 mM phosphate buffer (pH 2.6, 0.1 mM DTPA), and H2S measurement performed in an analogous manner to the one described above. The acid labile pool was determined by subtracting the free hydrogen sulfide value from the value obtained by the acid liberation protocol. The bound sulfane sulfur pool was determined by subtracting the H2S measurement from the acid liberation protocol alone compared to that of TCEP plus acidic conditions. In summary, our new method protocol allows very sensitive and accurate measurement of the three primary biological pools of H2S including free, acid labile, and bound sulfane sulfur in various biological specimens. PMID:22561703

  20. 40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... measuring hydrogen sulfide in acid gas-Tutwiler Procedure? 60.5408 Section 60.5408 Protection of Environment... § 60.5408 What is an optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine....

  1. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with...

  2. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment..., 2011 § 60.648 Optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a...

  3. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment..., 2011 § 60.648 Optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a...

  4. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with...

  5. 40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... measuring hydrogen sulfide in acid gas-Tutwiler Procedure? 60.5408 Section 60.5408 Protection of Environment... § 60.5408 What is an optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine....

  6. 40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with...

  7. Sulfur as a Signaling Nutrient Through Hydrogen Sulfide

    PubMed Central

    Kabil, Omer; Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H2S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H2S-based therapeutics is hampered by fundamental gaps in our knowledge of how H2S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H2S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease. PMID:25033061

  8. Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review.

    PubMed

    Greabu, Maria; Totan, Alexandra; Miricescu, Daniela; Radulescu, Radu; Virlan, Justina; Calenic, Bogdan

    2016-01-01

    In the past years, biomedical research has recognized hydrogen sulfide (H?S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H?S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H?S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases. PMID:26805896

  9. Release and control of hydrogen sulfide during sludge thermal drying

    SciTech Connect

    Weng, Huanxin; Dai, Zhixin; Ji, Zhongqiang; Gao, Caixia; Liu, Chongxuan

    2015-04-15

    The release of hydrogen sulfide (H2S) during sludge drying is a major environmental problem because of its toxicity to human health. A series of experiments were performed to investigate the mechanisms and factors controlling the H2S release. Results of this study show that: 1) the biomass and activity of sulfate-reducing bacteria (SRB) in sludge were the major factors controlling the amount of H2S release, 2) the sludge drying temperature had an important effect on both the extent and the timing of H2S release from the sludge, and 3) decreasing sludge pH increased the H2S release. Based on the findings from this study, a new system that integrates sludge drying and H2S gas treatment was developed to reduce the amount of H2S released from sludge treatments.

  10. Role of Hydrogen Sulfide in Ischemia-Reperfusion Injury

    PubMed Central

    Wu, Dongdong; Wang, Jun; Li, Hui; Xue, Mengzhou; Ji, Ailing; Li, Yanzhang

    2015-01-01

    Ischemia-reperfusion (I/R) injury is one of the major causes of high morbidity, disability, and mortality in the world. I/R injury remains a complicated and unresolved situation in clinical practice, especially in the field of solid organ transplantation. Hydrogen sulfide (H2S) is the third gaseous signaling molecule and plays a broad range of physiological and pathophysiological roles in mammals. H2S could protect against I/R injury in many organs and tissues, such as heart, liver, kidney, brain, intestine, stomach, hind-limb, lung, and retina. The goal of this review is to highlight recent findings regarding the role of H2S in I/R injury. In this review, we present the production and metabolism of H2S and further discuss the effect and mechanism of H2S in I/R injury. PMID:26064416

  11. Protein-based nanobiosensor for direct detection of hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Omidi, Meisam; Amoabediny, Ghasem; Yazdian, Fatemeh; Habibi-Rezaei, M.

    2015-01-01

    The chemically modified cytochrome c from equine heart, EC (232-700-9), was immobilized onto gold nanoparticles in order to develop a specific biosensing system for monitoring hydrogen sulfide down to the micromolar level, by means of a localized surface plasmon resonance spectroscopy. The sensing mechanism is based on the cytochrome-c conformational changes in the presence of H2S which alter the dielectric properties of the gold nanoparticles and the surface plasmon resonance peak undergoes a redshift. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 μ \\text{M} (1.3 \\text{ppb}) by the fabricated biosensor. This simple, quantitative and sensitive sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

  12. Endogenous hydrogen sulfide is involved in the pathogenesis of atherosclerosis

    SciTech Connect

    Qiao, Wang; Chaoshu, Tang; Key Laboratory of Molecular Cardiovascular Medicine, Ministry of Education ; Hongfang, Jin; Junbao, Du

    2010-05-28

    Atherosclerosis is a chronic, complex, and progressive pathological process in large and medium sized arteries. The exact mechanism of this process remains unclear. Hydrogen sulfide (H{sub 2}S), a novel gasotransmitter, was confirmed as playing a major role in the pathogenesis of many cardiovascular diseases. It plays a role in vascular smooth muscle cell (VSMC) proliferation and apoptosis, participates in the progress of hyperhomocysteinemia (HHCY), inhibits atherogenic modification of LDL, interferes with vascular calcification, intervenes with platelet function, and there are interactions between H{sub 2}S and inflammatory processes. The role of H{sub 2}S in atherosclerotic pathogenesis highlights the mysteries of atherosclerosis and inspires the search for innovative therapeutic strategies. Here, we review the studies to date that have considered the role of H{sub 2}S in atherosclerosis.

  13. Working with nitric oxide and hydrogen sulfide in biological systems

    PubMed Central

    Yuan, Shuai; Kevil, Christopher G.

    2014-01-01

    Nitric oxide (NO) and hydrogen sulfide (H2S) are gasotransmitter molecules important in numerous physiological and pathological processes. Although these molecules were first known as environmental toxicants, it is now evident that that they are intricately involved in diverse cellular functions with impact on numerous physiological and pathogenic processes. NO and H2S share some common characteristics but also have unique chemical properties that suggest potential complementary interactions between the two in affecting cellular biochemistry and metabolism. Central among these is the interactions between NO, H2S, and thiols that constitute new ways to regulate protein function, signaling, and cellular responses. In this review, we discuss fundamental biochemical principals, molecular functions, measurement methods, and the pathophysiological relevance of NO and H2S. PMID:25550314

  14. Hydrogen Sulfide Chemical Biology: Pathophysiological roles and detection

    PubMed Central

    Kolluru, Gopi K; Shen, Xinggui; Bir, Shyamal C.; Kevil, Christopher G.

    2014-01-01

    Hydrogen sulfide (H2S) is the most recent endogenous gasotransmitter that has been reported to serve many physiological and pathological functions in different tissues. Studies over the past decade have revealed that H2S can be synthesized through numerous pathways and its bioavailability regulated through its conversion into different biochemical forms. H2S exerts its biological effects in various manners including redox regulation of protein and small molecular weight thiols, polysulfides, thiosulfate/sulfite, iron-sulfur cluster proteins, and anti-oxidant properties that affect multiple cellular and molecular responses. However, precise measurement of H2S bioavailability and its associated biochemical and pathophysiological roles remains less well understood. In this review, we discuss recent understanding of H2S chemical biology, its relationship to tissue pathophysiological responses and possible therapeutic uses. PMID:23850632

  15. Observation of superconductivity in hydrogen sulfide from nuclear resonant scattering.

    PubMed

    Troyan, Ivan; Gavriliuk, Alexander; Rüffer, Rudolf; Chumakov, Alexander; Mironovich, Anna; Lyubutin, Igor; Perekalin, Dmitry; Drozdov, Alexander P; Eremets, Mikhail I

    2016-03-18

    High-temperature superconductivity remains a focus of experimental and theoretical research. Hydrogen sulfide (H2S) has been reported to be superconducting at high pressures and with a high transition temperature. We report on the direct observation of the expulsion of the magnetic field in H2S compressed to 153 gigapascals. A thin (119)Sn film placed inside the H2S sample was used as a sensor of the magnetic field. The magnetic field on the (119)Sn sensor was monitored by nuclear resonance scattering of synchrotron radiation. Our results demonstrate that an external static magnetic field of about 0.7 tesla is expelled from the volume of (119)Sn foil as a result of the shielding by the H2S sample at temperatures between 4.7 K and approximately 140 K, revealing a superconducting state of H2S. PMID:26989248

  16. The metallization and superconductivity of dense hydrogen sulfide

    SciTech Connect

    Li, Yinwei Hao, Jian; Li, Yanling; Liu, Hanyu; Ma, Yanming

    2014-05-07

    Hydrogen sulfide (H{sub 2}S) is a prototype molecular system and a sister molecule of water (H{sub 2}O). The phase diagram of solid H{sub 2}S at high pressures remains largely unexplored arising from the challenges in dealing with the pressure-induced weakening of S–H bond and larger atomic core difference between H and S. Metallization is yet achieved for H{sub 2}O, but it was observed for H{sub 2}S above 96 GPa. However, the metallic structure of H{sub 2}S remains elusive, greatly impeding the understanding of its metallicity and the potential superconductivity. We have performed an extensive structural study on solid H{sub 2}S at pressure ranges of 10–200 GPa through an unbiased structure prediction method based on particle swarm optimization algorithm. Besides the findings of candidate structures for nonmetallic phases IV and V, we are able to establish stable metallic structures violating an earlier proposal of elemental decomposition into sulfur and hydrogen [R. Rousseau, M. Boero, M. Bernasconi, M. Parrinello, and K. Terakura, Phys. Rev. Lett. 85, 1254 (2000)]. Our study unravels a superconductive potential of metallic H{sub 2}S with an estimated maximal transition temperature of ∼80 K at 160 GPa, higher than those predicted for most archetypal hydrogen-containing compounds (e.g., SiH{sub 4}, GeH{sub 4}, etc.)

  17. Hydrogen sulfide accelerates wound healing in diabetic rats

    PubMed Central

    Wang, Guoguang; Li, Wei; Chen, Qingying; Jiang, Yuxin; Lu, Xiaohua; Zhao, Xue

    2015-01-01

    Aim: The aim of this study was to explore the role of hydrogen sulfide on wound healing in diabetic rats. Methods: Experimental diabetes in rats was induced by intraperitoneal injection of streptozotocin (STZ) (in 0.1 mol/L citrate buffer, Ph 4.5) at dose of 70 mg/kg. Diabetic and age-matched non-diabetic rats were randomly assigned to three groups: untreated diabetic controls (UDC), treated diabetic administrations (TDA), and non-diabetic controls (NDC). Wound Healing Model was prepared by making a round incision (2.0 cm in diameter) in full thickness. Rats from TDA receive 2% sodium bisulfide ointment on wound, and animals from UDC and NDC receive control cream. After treatment of 21 days with sodium bisulfide, blood samples were collected for determination of vascular endothelial growth factor (VEGF), intercellular cell adhesion molecule-1 (ICAM-1), antioxidant effects. Granulation tissues from the wound were processed for histological examination and analysis of western blot. Results: The study indicated a significant increase in levels of VEGF and ICAM-1 and a decline in activity of coagulation in diabetic rats treated with sodium bisulfide. Sodium bisulfide treatment raised the activity of superoxide dismutase (SOD) and heme oxygenase-1 (HO-1) protein expression, and decreased tumor necrosis factor ? (TNF-?) protein expression in diabetic rats. Conclusions: The findings in present study suggested that hydrogen sulfide accelerates the wound healing in rats with diabetes. The beneficial effect of H2S may be associated with formation of granulation, anti-inflammation, antioxidant, and the increased level of vascular endothelial growth factor (VEGF). PMID:26191204

  18. Hydrogen Sulfide Is a Signaling Molecule and a Cytoprotectant

    PubMed Central

    Shibuya, Norihiro; Kimura, Yuka

    2012-01-01

    Abstract Significance: Accumulating evidence shows that hydrogen sulfide may function as a signaling molecule in processes such as neuromodulation in the brain and smooth muscle relaxation in the vascular system. It also has a cytoprotective effect, since it can protect neurons and cardiac muscle from oxidative stress and ischemia-reperfusion injury, respectively. Hydrogen sulfide can also modulate inflammation, insulin release, and angiogenesis. Recent Advances: The regulation of the activity of 3-mercaptopyruvate sulfur transferase (3MST) along with cysteine aminotransferase (CAT), one of the H2S producing pathways, has been demonstrated. The production of H2S by the pathway, which is regulated by Ca2+ and facilitated by thioredoxin and dihydrolipoic acid, is also involved in H2S signaling as well as cytoprotection. Sulfur hydration of proteins by H2S has been proposed to modulate protein functions. H2S-sensitive fluorescent probes, which enable us to measure the localization of H2S in real time, have been developed. Critical Issues: The basal concentrations of H2S have recently been measured and found to be much lower than those initially reported. However, the concentration of H2S reached in stimulated cells, as well as the regulation of H2S producing enzymes is not well understood. It has been proposed that some of the effects of H2S on the regulation of enzymes and receptors might be explained through the properties of sulfane sulfur (S0), another form of active sulfur. Future Directions: The determination of H2S concentrations in activated cells using new methods including H2S-sensitive fluorescent probes, as well as the investigation of the effects of H2S using specific inhibitors, may provide better understanding of the physiological function of this molecule. Clarifying mechanisms of H2S activity may also facilitate the development of new therapeutic compounds. Antioxid. Redox Signal. 17, 45–57. PMID:22229673

  19. Methods for producing hydrogen (BI) sulfide and/or removing metals

    DOEpatents

    Truex, Michael J [Richland, WA; Peyton, Brent M [Pullman, WA; Toth, James J [Kennewick, WA

    2002-05-14

    The present invention is a process wherein sulfide production by bacteria is efficiently turned on and off, using pH adjustment. The adjustment of pH impacts sulfide production by bacteria by altering the relative amounts of H.sub.2 S and HS-- in solution and thereby control the inhibition of the bacterial metabolism that produces sulfide. This process can be used to make a bioreactor produce sulfide "on-demand" so that the production of sulfide can be matched to its use as a metal precipitation reagent. The present invention is of significance because it enables the use of a biological reactor, a cost effective sulfide production system, by making the biological reactor produce hydrogen sulfide "on demand", and therefore responsive to production schedules, waste stream generation rate, and health and safety requirements/goals.

  20. Metal-organic frameworks for the storage and delivery of biologically active hydrogen sulfide

    SciTech Connect

    Allan, Phoebe K; Wheatley, Paul S; Aldous, David; Mohideen, M Infas; Tang, Chiu; Hriljac, Joseph A; Megson, Ian L; Chapman, Karena W; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E

    2012-04-02

    Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis.

  1. Metal-organic frameworks for the storage and delivery of biologically active hydrogen sulfide.

    PubMed

    Allan, Phoebe K; Wheatley, Paul S; Aldous, David; Mohideen, M Infas; Tang, Chiu; Hriljac, Joseph A; Megson, Ian L; Chapman, Karena W; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E

    2012-04-14

    Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis. PMID:22378060

  2. Reduced graphene oxide based silver sulfide hybrid films formed at a liquid/liquid interface

    SciTech Connect

    Bramhaiah, K. John, Neena S.

    2014-04-24

    Free-standing, ultra-thin films of silver sulfide and reduced graphene oxide (RGO) based silver sulfide hybrids are prepared at a liquid/liquid interface employing in situ chemical reaction strategy. Ag{sub 2}S and RGO?Ag{sub 2}S hybrid films are characterized by various techniques such as UV-visible and photo luminescence spectroscopy, X-ray diffraction and scanning electron microscopy. The morphology of hybrid films consists of Ag{sub 2}S nanocrystals on RGO surface while Ag{sub 2}S films contains branched network of dendritic structures. RGO?Ag{sub 2}S exhibit interesting optical and electrical properties. The hybrid films absorb in the region 500650 nm and show emission in the red region. A higher conductance is observed for the hybrid films arising from the RGO component. This simple low cost method can be extended to prepare other RGO based metal sulfides.

  3. A fatal case of hydrogen sulfide poisoning in a geothermal power plant.

    PubMed

    Kage, S; Ito, S; Kishida, T; Kudo, K; Ikeda, N

    1998-07-01

    An adult man entered an oil separator room to remove waste oil from a vacuum pump in a geothermal power plant. He suddenly collapsed and died soon after. Since hydrogen sulfide gas was detected in the atmosphere at the scene of the accident, poisoning by this gas was suspected and toxicological analysis of sulfide and thiosulfate in blood, brain, lung, femoral muscle was made using the extractive alkylation technique combined with gas chromatography/mass spectrometry (GC/MS). The concentrations of sulfide in these tissues were similar to those previously reported for fatal cases of hydrogen sulfide gas. The concentration of thiosulfate in the blood was at least 48 times higher than the level in control samples. Based on these results, the cause of death was attributed to hydrogen sulfide gas poisoning. PMID:9670519

  4. Stable Isotope Measurements of Carbon Dioxide, Methane, and Hydrogen Sulfide Gas Using Frequency Modulation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nowak-Lovato, K.

    2014-12-01

    Seepage from enhanced oil recovery, carbon storage, and natural gas sites can emit trace gases such as carbon dioxide, methane, and hydrogen sulfide. Trace gas emission at these locations demonstrate unique light stable isotope signatures that provide information to enable source identification of the material. Light stable isotope detection through surface monitoring, offers the ability to distinguish between trace gases emitted from sources such as, biological (fertilizers and wastes), mineral (coal or seams), or liquid organic systems (oil and gas reservoirs). To make light stable isotope measurements, we employ the ultra-sensitive technique, frequency modulation spectroscopy (FMS). FMS is an absorption technique with sensitivity enhancements approximately 100-1000x more than standard absorption spectroscopy with the advantage of providing stable isotope signature information. We have developed an integrated in situ (point source) system that measures carbon dioxide, methane and hydrogen sulfide with isotopic resolution and enhanced sensitivity. The in situ instrument involves the continuous collection of air and records the stable isotope ratio for the gas being detected. We have included in-line flask collection points to obtain gas samples for validation of isotopic concentrations using our in-house isotope ratio mass spectroscopy (IRMS). We present calibration curves for each species addressed above to demonstrate the sensitivity and accuracy of the system. We also show field deployment data demonstrating the capabilities of the system in making live dynamic measurements from an active source.

  5. Transient Kinetic Analysis of Hydrogen Sulfide Oxidation Catalyzed by Human Sulfide Quinone Oxidoreductase.

    PubMed

    Mishanina, Tatiana V; Yadav, Pramod K; Ballou, David P; Banerjee, Ruma

    2015-10-01

    The first step in the mitochondrial sulfide oxidation pathway is catalyzed by sulfide quinone oxidoreductase (SQR), which belongs to the family of flavoprotein disulfide oxidoreductases. During the catalytic cycle, the flavin cofactor is intermittently reduced by sulfide and oxidized by ubiquinone, linking H2S oxidation to the electron transfer chain and to energy metabolism. Human SQR can use multiple thiophilic acceptors, including sulfide, sulfite, and glutathione, to form as products, hydrodisulfide, thiosulfate, and glutathione persulfide, respectively. In this study, we have used transient kinetics to examine the mechanism of the flavin reductive half-reaction and have determined the redox potential of the bound flavin to be -123 ± 7 mV. We observe formation of an unusually intense charge-transfer (CT) complex when the enzyme is exposed to sulfide and unexpectedly, when it is exposed to sulfite. In the canonical reaction, sulfide serves as the sulfur donor and sulfite serves as the acceptor, forming thiosulfate. We show that thiosulfate is also formed when sulfide is added to the sulfite-induced CT intermediate, representing a new mechanism for thiosulfate formation. The CT complex is formed at a kinetically competent rate by reaction with sulfide but not with sulfite. Our study indicates that sulfide addition to the active site disulfide is preferred under normal turnover conditions. However, under pathological conditions when sulfite concentrations are high, sulfite could compete with sulfide for addition to the active site disulfide, leading to attenuation of SQR activity and to an alternate route for thiosulfate formation. PMID:26318450

  6. No facilitator required for membrane transport of hydrogen sulfide

    PubMed Central

    Mathai, John C.; Missner, Andreas; Kgler, Philipp; Saparov, Sapar M.; Zeidel, Mark L.; Lee, John K.; Pohl, Peter

    2009-01-01

    Hydrogen sulfide (H2S) has emerged as a new and important member in the group of gaseous signaling molecules. However, the molecular transport mechanism has not yet been identified. Because of structural similarities with H2O, it was hypothesized that aquaporins may facilitate H2S transport across cell membranes. We tested this hypothesis by reconstituting the archeal aquaporin AfAQP from sulfide reducing bacteria Archaeoglobus fulgidus into planar membranes and by monitoring the resulting facilitation of osmotic water flow and H2S flux. To measure H2O and H2S fluxes, respectively, sodium ion dilution and buffer acidification by proton release (H2S ? H+ + HS?) were recorded in the immediate membrane vicinity. Both sodium ion concentration and pH were measured by scanning ion-selective microelectrodes. A lower limit of lipid bilayer permeability to H2S, PM,H2S ? 0.5 0.4 cm/s was calculated by numerically solving the complete system of differential reaction diffusion equations and fitting the theoretical pH distribution to experimental pH profiles. Even though reconstitution of AfAQP significantly increased water permeability through planar lipid bilayers, PM,H2S remained unchanged. These results indicate that lipid membranes may well act as a barrier to water transport although they do not oppose a significant resistance to H2S diffusion. The fact that cholesterol and sphingomyelin reconstitution did not turn these membranes into an H2S barrier indicates that H2S transport through epithelial barriers, endothelial barriers, and membrane rafts also occurs by simple diffusion and does not require facilitation by membrane channels. PMID:19805349

  7. The Determination of Hydrogen Sulfide in Stack Gases, Iodometric Titration After Sulfite Removal.

    ERIC Educational Resources Information Center

    Robles, E. G.

    The determination of hydrogen sulfide in effluents from coal-fired furnaces and incinerators is complicated by the presence of sulfur oxides (which form acids). Organic compounds also may interfere with or prevent the formation of the cadmium sulfide precipitate or give false positive results because of reaction with iodine. The report presents a

  8. The Determination of Hydrogen Sulfide in Stack Gases, Iodometric Titration After Sulfite Removal.

    ERIC Educational Resources Information Center

    Robles, E. G.

    The determination of hydrogen sulfide in effluents from coal-fired furnaces and incinerators is complicated by the presence of sulfur oxides (which form acids). Organic compounds also may interfere with or prevent the formation of the cadmium sulfide precipitate or give false positive results because of reaction with iodine. The report presents a…

  9. Nanoporous metal enhanced catalytic activities of amorphous molybdenum sulfide for high-efficiency hydrogen production.

    PubMed

    Ge, Xingbo; Chen, Luyang; Zhang, Ling; Wen, Yuren; Hirata, Akihiko; Chen, Mingwei

    2014-05-21

    We fabricated a robust electrocatalyst by chemically depositing an ultrathin layer of amorphous molybdenum sulfide on the internal surface of dealloyed nanoporous gold. The catalyst exhibits superior electrocatalysis toward hydrogen evolution reaction in both acidic and neutral media with 2-6 times improvement in catalytic activies compared to other molybdenum sulfide based materials. PMID:24554595

  10. Rate controlling processes for crack growth in hydrogen sulfide for an alsl 4340 steel

    NASA Astrophysics Data System (ADS)

    Lu, M.; Pao, P. S.; Weir, T. W.; Simmons, G. W.; Wei, R. P.

    1981-05-01

    Parallel fracture mechanics and surface chemistry studies were carried out to develop further understanding of environment assisted subcritical crack growth in high strength steels. The kinetics of crack growth for an AISI 4340 steel (tempered at 477 K) in high purity hydrogen sulfide have been determined as a function of pressure at room temperature and as a function of temperature at hydrogen sulfide pressures of 0.133 and 2.66 kPa. The kinetics for the reactions of hydrogen sulfide with this steel and the extent of reactions were also determined. Two rate controlling processes have been identified. At the lower pressure, the rate of crack growth varies according to T1/2 and is controlled by the rate of transport of hydrogen sulfide to the crack tip. At the higher pressure, crack growth is controlled by the rate of diffusion of hydrogen into the steel ahead of the crack tip and exhibits an apparent activation energy of about 5 kJ/mol. Embrittlement results from hydrogen that is produced by the reactions of hydrogen sulfide with the steel. These reactions are extremely rapid and are limited in extent, leading to the formation of one to two layers of sulfide on the fracture surfaces. The crack growth results are discussed in terms of measured reaction kinetics and published data on diffusion, and in relation to models for transport- and diffusion-controlled crack growth.

  11. Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling.

    PubMed

    Charles, W; Cord-Ruwisch, R; Ho, G; Costa, M; Spencer, P

    2006-01-01

    The Woodman Point Wastewater Treatment Plant (WWTP) in Western Australia has experienced two separate problems causing avoidable maintenance costs: the build-up of massive struvite (MgNH4PO4. 6H2O) scaling downstream of the anaerobic digester and the formation of hydrogen sulfide (H2S) levels in the digester gas to levels that compromised gas engine operation and caused high operating costs on the gas scrubber. As both problems hang together with a chemical imbalance in the anaerobic digester, we decided to investigate whether both problems could be (feasibly and economically) addressed by a common solution (such as dosing of iron solutions to precipitate both sulfide and phosphate), or by using separate approaches. Laboratory results showed that, the hydrogen sulfide emission in digesters could be effectively and economically controlled by the addition of iron dosing. Slightly higher than the theoretical value of 1.5 mol of FeCl3 was required to precipitate 1 mol of dissolved sulfide inside the digester. Due to the high concentration of PO4(3-) in the digested sludge liquor, significantly higher iron is required for struvite precipitation. Iron dosing did not appear an economic solution for struvite control via iron phosphate formation. By taking advantage of the natural tendency of struvite formation in the digester liquid, it is possible to reduce the risk of struvite precipitation in and around the sludge-dewatering centrifuge by increasing the pH to precipitate struvite out before passing through the centrifuge. However, as the Mg2+/PO4(3-) molar ratio in digested sludge was low, by increasing the pH alone (using NaOH) the precipitation of PO4(3-) was limited by the amount of cations (Ca2+ and Mg2+) available in the sludge. Although this would reduce struvite precipitation in the centrifuge, it could not significantly reduce PO4(3-) recycling back to the plant. For long-term operation, maximum PO4(3-) reduction should be the ultimate aim to minimise PO4(3-) accumulation in the plant. Magnesium hydroxide liquid (MHL) was found to be the most cost-effective chemical to achieve this goal. It enhanced struvite precipitation from both, digested sludge and centrate to the point where more than 95% PO4(3-) reduction in the digested sludge was achieved. PMID:16749459

  12. EMERSION IN THE MANGROVE FOREST FISH 'RIVULUS MARMORATUS': A UNIQUE RESPONSE TO HYDROGEN SULFIDE

    EPA Science Inventory

    The mangrove forest fish Rivulus marmoratus (Cyprinodontidae) has frequently been observed out of water, a phenomenon generally attributed to habitat drying. The authors tested the hypothesis that hydrogen sulfide, a substance characteristically found in their environment, can se...

  13. Occupationally related hydrogen sulfide deaths in the United States from 1984 to 1994.

    PubMed

    Fuller, D C; Suruda, A J

    2000-09-01

    Alice Hamilton described fatal work injuries from acute hydrogen sulfide poisonings in 1925 in her book Industrial Poisons in the United States. There is no unique code for H2S poisoning in the International Classification of Diseases, 9th Revision; therefore, these deaths cannot be identified easily from vital records. We reviewed US Occupational Safety and Health Administration (OSHA) investigation records for the period 1984 to 1994 for mention of hazardous substance 1480 (hydrogen sulfide). There were 80 fatalities from hydrogen sulfide in 57 incidents, with 19 fatalities and 36 injuries among coworkers attempting to rescue fallen workers. Only 17% of the deaths were at workplaces covered by collective bargaining agreements. OSHA issued citations for violation of respiratory protection and confined space standards in 60% of the fatalities. The use of hydrogen sulfide detection equipment, air-supplied respirators, and confined space safety training would have prevented most of the fatalities. PMID:10998771

  14. Process for removal of carbonyl sulfide in liquified hydrocarbon gases with absorption of acid gases

    SciTech Connect

    Beavon, D.K.; Mackles, M.

    1980-11-11

    Liquified hydrocarbon gases containing at least carbonyl sulfide as an impurity are purified by intimately mixing the liquified hydrocarbon gas with an aqueous absorbent for hydrogen sulfide in a hydrolysis zone maintained at a temperature and a pressure sufficient to maintain the liquified hydrocarbon gas in the liquid state and hydrolyze the carbonyl sulfide to hydrogen sulfide and carbon dioxide. The liquified hydrocarbon gas containing at least a portion of the formed carbonyl sulfide and carbon dioxide is separated from the liquid absorbent and passed to an absorption zone where it is contacted with a liquid hydrogen sulfide absorbent where at least the formed hydrogen sulfide is separated from the liquified petroleum gas. A stage of absorption of at least hydrogen sulfide may proceed mixing of the liquified hydrocarbon gas with the absorbent in the hydrolysis reaction zone. The absorbent employed does not combine irreversibly with carbonyl sulfide, hydrogen sulfide, and carbon dioxide, and preferably is an aqueous solution of diethanolamine.

  15. Thermal diffusion in metal-sulfide liquids - Early results

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Walker, D.

    1991-01-01

    Experiments were carried out to evaluate the Soret effect in liquid Fe-Ni-S-P alloys in order to gain a better understanding of the physical and thermodynamic properties of metallic liquids and to assess the possibility of systematic errors in Czochralski growth techniques. The metal-sulfide liquids were found to show a substantial Soret effect and, contrary to previous expectation, can be as large as that seen in the silicate system. The segregation is largely produced by S-Fe interactions. The P redistribution occurs to reduce activity gradients in P consequent upon S gradients, and P segregation can be approximately predicted in Fe-Ni-S liquids using the activity model of Jones and Malvin (1990). It is inferred that the sense of the Soret segregation, with P going to the cold end and S going to the hot end, is in accordance with the prediction of Malvin et al. (1986), who speculated that the crystal-pulling experiments of Sellamuthu and Goldstein (1985) was influenced by the Soret effect.

  16. Development of the Transferable Potentials for Phase Equilibria Model for Hydrogen Sulfide.

    PubMed

    Shah, Mansi S; Tsapatsis, Michael; Siepmann, J Ilja

    2015-06-11

    The transferable potentials for phase equilibria force field is extended to hydrogen sulfide. The pure-component and binary vapor-liquid equilibria with methane and carbon dioxide and the liquid-phase relative permittivity are used for the parametrization of the Lennard-Jones (LJ) and Coulomb interactions, and models with three and four interaction sites are considered. For the three-site models, partial point charges are placed on the sites representing the three atoms, while the negative partial charge is moved to an off-atom site for the four-site models. The effect of molecular shape is probed using either only a single LJ interaction site on the sulfur atom or adding sites also on the hydrogen atoms. This procedure results in four distinct models, but only those with three LJ sites can accurately reproduce all properties considered for the parametrization. These two are further assessed for predictions of the liquid-phase structure, the lattice parameters and relative permittivity for the face-centered-cubic solid, and the triple point. An effective balance between LJ interactions and the dipolar and quadrupolar terms of the first-order electrostatic interactions is struck in order to obtain a four-site model that describes the condensed-phase properties and the phase equilibria with high accuracy. PMID:25981731

  17. Hydrogen sulfide scavengers market assessment. Topical report, June 16-December 15, 1995

    SciTech Connect

    Houston, C.W.

    1996-03-01

    The report objective was to establish the dollar market size for removing low level concentrations of hydrogen sulfide from natural gas using commercially available scavengers, identify the key players, and determine significant trends in the industry. The study established the oilfield and refinery markets for the treating of natural gas, with hydrogen sulfide scavengers. The total North American market is estimated to be worth $172 million in 1995. Natural gas stream or vapor phase treating represents 85 percent of the total market.

  18. Biogenesis of reactive sulfur species for signaling by hydrogen sulfide oxidation pathways.

    PubMed

    Mishanina, Tatiana V; Libiad, Marouane; Banerjee, Ruma

    2015-07-01

    The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity. PMID:26083070

  19. Organization of the Human Mitochondrial Hydrogen Sulfide Oxidation Pathway*♦

    PubMed Central

    Libiad, Marouane; Yadav, Pramod Kumar; Vitvitsky, Victor; Martinov, Michael; Banerjee, Ruma

    2014-01-01

    Sulfide oxidation is expected to play an important role in cellular switching between low steady-state intracellular hydrogen sulfide levels and the higher concentrations where the physiological effects are elicited. Yet despite its significance, fundamental questions regarding how the sulfide oxidation pathway is wired remain unanswered, and competing proposals exist that diverge at the very first step catalyzed by sulfide quinone oxidoreductase (SQR). We demonstrate that, in addition to sulfite, glutathione functions as a persulfide acceptor for human SQR and that rhodanese preferentially synthesizes rather than utilizes thiosulfate. The kinetic behavior of these enzymes provides compelling evidence for the flow of sulfide via SQR to glutathione persulfide, which is then partitioned to thiosulfate or sulfite. Kinetic simulations at physiologically relevant metabolite concentrations provide additional support for the organizational logic of the sulfide oxidation pathway in which glutathione persulfide is the first intermediate formed. PMID:25225291

  20. Experimental Observations on the Biological Significance of Hydrogen Sulfide in Carotid Body Chemoreception.

    PubMed

    Gallego-Martin, T; Agapito, T; Ramirez, M; Olea, E; Yubero, S; Rocher, A; Gomez-Nio, A; Obeso, A; Gonzalez, C

    2015-01-01

    The cascade of transduction of hypoxia and hypercapnia, the natural stimuli to chemoreceptor cells, is incompletely understood. A particular gap in that knowledge is the role played by second messengers, or in a most ample term, of modulators. A recently described modulator of chemoreceptor cell responses is the gaseous transmitter hydrogen sulfide, which has been proposed as a specific activator of the hypoxic responses in the carotid body, both at the level of the chemoreceptor cell response or at the level of the global output of the organ. Since sulfide behaves in this regard as cAMP, we explored the possibility that sulfide effects were mediated by the more classical messenger. Data indicate that exogenous and endogenous sulfide inhibits adenyl cyclase finding additionally that inhibition of adenylyl cyclase does not modify chemoreceptor cell responses elicited by sulfide. We have also observed that transient receptor potential cation channels A1 (TRPA1) are not regulated by sulfide in chemoreceptor cells. PMID:26303462

  1. Hydrogen Sulfide as a Potential Therapeutic Target in Fibrosis

    PubMed Central

    Zhang, Shufang; Pan, Chuli; Zhou, Feifei; Yuan, Zhi; Wang, Huiying; Cui, Wei; Zhang, Gensheng

    2015-01-01

    Hydrogen sulfide (H2S), produced endogenously by the activation of two major H2S-generating enzymes (cystathionine ?-synthase and cystathionine ?-lyase), plays important regulatory roles in different physiologic and pathologic conditions. The abnormal metabolism of H2S is associated with fibrosis pathogenesis, causing damage in structure and function of different organs. A number of in vivo and in vitro studies have shown that both endogenous H2S level and the expressions of H2S-generating enzymes in plasma and tissues are significantly downregulated during fibrosis. Supplement with exogenous H2S mitigates the severity of fibrosis in various experimental animal models. The protective role of H2S in the development of fibrosis is primarily attributed to its antioxidation, antiapoptosis, anti-inflammation, proangiogenesis, and inhibition of fibroblasts activities. Future studies might focus on the potential to intervene fibrosis by targeting the pathway of endogenous H2S-producing enzymes and H2S itself. PMID:26078809

  2. Physiological implications of hydrogen sulfide: a whiff exploration that blossomed.

    PubMed

    Wang, Rui

    2012-04-01

    The important life-supporting role of hydrogen sulfide (H(2)S) has evolved from bacteria to plants, invertebrates, vertebrates, and finally to mammals. Over the centuries, however, H(2)S had only been known for its toxicity and environmental hazard. Physiological importance of H(2)S has been appreciated for about a decade. It started by the discovery of endogenous H(2)S production in mammalian cells and gained momentum by typifying this gasotransmitter with a variety of physiological functions. The H(2)S-catalyzing enzymes are differentially expressed in cardiovascular, neuronal, immune, renal, respiratory, gastrointestinal, reproductive, liver, and endocrine systems and affect the functions of these systems through the production of H(2)S. The physiological functions of H(2)S are mediated by different molecular targets, such as different ion channels and signaling proteins. Alternations of H(2)S metabolism lead to an array of pathological disturbances in the form of hypertension, atherosclerosis, heart failure, diabetes, cirrhosis, inflammation, sepsis, neurodegenerative disease, erectile dysfunction, and asthma, to name a few. Many new technologies have been developed to detect endogenous H(2)S production, and novel H(2)S-delivery compounds have been invented to aid therapeutic intervention of diseases related to abnormal H(2)S metabolism. While acknowledging the challenges ahead, research on H(2)S physiology and medicine is entering an exponential exploration era. PMID:22535897

  3. Updated cost estimates of meeting geothermal hydrogen sulfide emission regulations

    SciTech Connect

    Wells, K.D.; Currie, J.W.; Weakley, S.A.; Ballinger, M.Y.

    1981-08-01

    A means of estimating the cost of hydrogen sulfide (H/sub 2/S) emission control was investigated. This study was designed to derive H/sub 2/S emission abatement cost functions and illustrate the cost of H/sub 2/S emission abatement at a hydrothermal site. Four tasks were undertaken: document the release of H/sub 2/S associated with geothermal development; review H/sub 2/S environmental standards; develop functional relationships that may be used to estimate the most cose-effective available H/sub 2/S abatement process; and use the cost functions to generate abatement cost estimates for a specific site. The conclusions and recommendations derived from the research are presented. The definition of the term impacts as used in this research is discussed and current estimates of the highest expected H/sub 2/S concentrations of in geothermal reservoirs are provided. Regulations governing H/sub 2/S emissions are reviewed and a review of H/sub 2/S control technology and a summary of the control cost functions are included. A case study is presented to illustrate H/sub 2/S abatement costs at the Baca KGRA in New Mexico.

  4. PROVISIONAL ADVISORY LEVELS (PALs) FOR HYDROGEN SULFIDE (H2S)

    SciTech Connect

    Marshall, Thomas C; Dorman, David; Gardner, Donald; Adeshina, Femi; Ross, Robert Hord

    2009-01-01

    Application of PAL protocols was performed for hydrogen sulfide (H2S) as experimental data permitted. The data base includes human experimental studies, worker exposure evaluations, as well as case studies on acute and repeated exposure. The data base of animal studies is substantial covering multiple species and addressing acute, repeated, and subchronic exposure scenarios. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in November 2006. No reliable data were found on oral exposure, making it impractical to estimate PALs for drinking water. Since H2S exists as a gas, partitioning to air is likely to occur with an environmental release. H2S inhalation PAL values for 24 hr exposure are: PAL 1 = 1.2 ppm; PAL 2 = 7.0 ppm; and PAL 3 = 27 ppm; the 30-d and 90-d inhalation exposure values are: PAL 1 = 0.85 ppm and PAL 2 = 3.0 ppm. PAL 3 values for 30-d and 90-d are not recommended due to insufficient data. Long-term data were insufficient to estimate 2-year inhalation PALs.

  5. Interactions between oxygen homeostasis, food availability, and hydrogen sulfide signaling

    PubMed Central

    Iranon, Nicole N.; Miller, Dana L.

    2012-01-01

    The ability to sense and respond to stressful conditions is essential to maintain organismal homeostasis. It has long been recognized that stress response factors that improve survival in changing conditions can also influence longevity. In this review, we discuss different strategies used by animals in response to decreased O2 (hypoxia) to maintain O2 homeostasis, and consider interactions between hypoxia responses, nutritional status, and H2S signaling. O2 is an essential environmental nutrient for almost all metazoans as it plays a fundamental role in development and cellular metabolism. However, the physiological response(s) to hypoxia depend greatly on the amount of O2 available. Animals must sense declining O2 availability to coordinate fundamental metabolic and signaling pathways. It is not surprising that factors involved in the response to hypoxia are also involved in responding to other key environmental signals, particularly food availability. Recent studies in mammals have also shown that the small gaseous signaling molecule hydrogen sulfide (H2S) protects against cellular damage and death in hypoxia. These results suggest that H2S signaling also integrates with hypoxia response(s). Many of the signaling pathways that mediate the effects of hypoxia, food deprivation, and H2S signaling have also been implicated in the control of lifespan. Understanding how these pathways are coordinated therefore has the potential to reveal new cellular and organismal homeostatic mechanisms that contribute to longevity assurance in animals. PMID:23233860

  6. Hydrogen sulfide: the third gasotransmitter in biology and medicine.

    PubMed

    Wang, Rui

    2010-05-01

    The last two decades have seen one of the greatest excitements and discoveries in science, gasotransmitters in biology and medicine. Leading the trend by nitric oxide and extending the trudge by carbon monoxide, here comes hydrogen sulfide (H(2)S) who builds up the momentum as the third gasotransmitter. Being produced by different cells and tissues in our body, H(2)S, alone or together with the other two gasotransmitters, regulates an array of physiological processes and plays important roles in the pathogenesis of various diseases from neurodegenerative diseases to diabetes or heart failure, to name a few. As a journal dedicated to serve the emergent and challenging field of H(2)S biology and medicine, Antioxidant and Redox Signaling assembles the most recent discoveries and most provoking ideas from leading scientists in H(2)S fields, which were communicated in the First International Conference of H(2)S in Biology and Medicine, and brings them to our readers in two Forum Issues. Through intellectual exchange and intelligent challenge with an open-mind approach, we can reasonably expect that sooner rather than later the exploration of metabolism and function of H(2)S will provide solutions for many of the biological mysteries of life and pave way for the arrival of many more gasotransmitters. PMID:19845469

  7. [Hydrogen sulfide: A promising therapy in neuroprotection following cardiac arrest?].

    PubMed

    Sayouri, H; Boudier, A; Vigneron, C; Leroy, P; Le Tacon, S

    2015-11-01

    Each year, in France, the number of cardiac arrests is evaluated between 30,000 to 50,000. When a patient survives, he undergoes a post-resuscitation syndrome which can aggravate the injuries and for which nowadays, no medication is available. In some kinds of cardiac arrest, a hypothermia protocol can be applied with a need for monitoring because of the appearance of side effects. In this context, hydrogen sulfide, which is a gasotransmitter with numerous physiological and pharmacological properties, may be interesting. Indeed, its use could protect against oxidative, inflammatory and apoptotic troubles induced by the post-resuscitation syndrome. The implied biochemical mechanisms are adenosine triphosphate potassium channels activation and cytochrome c oxidase inhibition. This molecule can also induce a suspended animation state characterized by a metabolism decrease, which could give a delay for physicians to start a therapeutic monitoring. Thus, in spite of a modest and sometimes contradictory literature, this compound could become the first neuroprotective molecule in cardiac arrest. PMID:26033567

  8. Hydrogen Sulfide Donor GYY4137 Protects against Myocardial Fibrosis

    PubMed Central

    Meng, Guoliang; Zhu, Jinbiao; Xiao, Yujiao; Huang, Zhengrong; Zhang, Yuqing; Tang, Xin; Xie, Liping; Chen, Yu; Shao, Yongfeng; Ferro, Albert; Wang, Rui; Moore, Philip K.; Ji, Yong

    2015-01-01

    Hydrogen sulfide (H2S) is a gasotransmitter which regulates multiple cardiovascular functions. However, the precise roles of H2S in modulating myocardial fibrosis in vivo and cardiac fibroblast proliferation in vitro remain unclear. We investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial fibrosis. Spontaneously hypertensive rats (SHR) were administrated with GYY4137 by intraperitoneal injection daily for 4 weeks. GYY4137 decreased systolic blood pressure and inhibited myocardial fibrosis in SHR as evidenced by improved cardiac collagen volume fraction (CVF) in the left ventricle (LV), ratio of perivascular collagen area (PVCA) to lumen area (LA) in perivascular regions, reduced hydroxyproline concentration, collagen I and III mRNA expression, and cross-linked collagen. GYY4137 also inhibited angiotensin II- (Ang II-) induced neonatal rat cardiac fibroblast proliferation, reduced the number of fibroblasts in S phase, decreased collagen I and III mRNA expression and protein synthesis, attenuated oxidative stress, and suppressed ?-smooth muscle actin (?-SMA), transforming growth factor-?1 (TGF-?1) expression as well as Smad2 phosphorylation. These results indicate that GYY4137 improves myocardial fibrosis perhaps by a mechanism involving inhibition of oxidative stress, blockade of the TGF-?1/Smad2 signaling pathway, and decrease in ?-SMA expression in cardiac fibroblasts. PMID:26078813

  9. [Severe hydrogen sulfide intoxication: a pediatric case of survival].

    PubMed

    Claudet, I; Marcoux, M-O; Karsenty, C; Ritti, J-L; Honorat, R; Lelong-Tissier, M-C

    2012-03-01

    We report a paediatric case of survival following severe hydrogen sulfide (H2S) gas intoxication. A 13-year-old boy was found submerged to the neck in a manure tank. He was hypothermic, unresponsive with bilateral mydriasis, and had poor oxygen saturation. After intubation, he was transferred to the paediatric intensive care unit of a tertiary care children's hospital. He developed acute respiratory distress syndrome (ARDS) requiring high frequency percussive ventilation. Cardiac evaluation was significant for myocardial infarction and left ventricular function impairment. He completely recovered from the respiratory and cardiac failure. Neurological examinations showed abnormal signals on MRI in the semi-oval center and in the frontal cortex. Follow-up detected partial impairment of axonal fibers of the right external popliteal sciatic nerve. Paediatric cases of survival after H2S intoxication have been rarely reported. Such exposures can evolve to severe ARDS and benefit from high frequency percussive ventilation. Hypothermia and other metabolic abnormalities are now better explained thanks to actual knowledge about endogenous H2S function. Lessons learned from paediatric accidents should result in better information about this threat for farmers and families living in houses with septic tanks, reducing the risk to their own and their children's safety. PMID:22305402

  10. Endogenous Hydrogen Sulfide Production Is Essential for Dietary Restriction Benefits

    PubMed Central

    Hine, Christopher; Harputlugil, Eylul; Zhang, Yue; Ruckenstuhl, Christoph; Lee, Byung Cheon; Brace, Lear; Longchamp, Alban; Trevino-Villarreal, Jose H.; Mejia, Pedro; Ozaki, C. Keith; Wang, Rui; Gladyshev, Vadim N.; Madeo, Frank; Mair, William B.; Mitchell, James R.

    2014-01-01

    Summary Dietary restriction (DR) without malnutrition encompasses numerous regimens with overlapping benefits including longevity and stress resistance, but unifying nutritional and molecular mechanisms remain elusive. In a mouse model of DR-mediated stress resistance, we found that sulfur amino acid (SAA) restriction increased expression of the transsulfuration pathway (TSP) enzyme cystathionine ?-lyase (CGL), resulting in increased hydrogen sulfide (H2S) production and protection from hepatic ischemia reperfusion injury. SAA supplementation, mTORC1 activation, or chemical/genetic CGL inhibition reduced H2S production and blocked DR-mediated stress resistance. In vitro, the mitochondrial protein SQR was required for H2S-mediated protection during nutrient/oxygen deprivation. Finally, TSP-dependent H2S production was observed in yeast, worm, fruit fly and rodent models of DR-mediated longevity. Together, these data are consistent with evolutionary conservation of TSP-mediated H2S as a novel mediator of DR benefits with broad implications for clinical translation. PMID:25542313

  11. Hydrogen Sulfide as Endothelial Derived Hyperpolarizing Factor Sulfhydrates Potassium Channels

    PubMed Central

    Mustafa, Asif K.; Sikka, Gautam; Gazi, Sadia K.; Steppan, Jochen; Jung, Sung M.; Bhunia, Anil K.; Barodka, Viachaslau M.; Gazi, Farah K.; Barrow, Roxanne K.; Wang, Rui; Amzel, L. Mario; Berkowitz, Dan E.; Snyder, Solomon H.

    2011-01-01

    Rationale Nitric oxide, the classic endothelial derived relaxing factor (EDRF), acts via cyclic GMP and calcium without notably affecting membrane potential. A major component of EDRF activity derives from hyperpolarization and is termed endothelial derived hyperpolarizing factor (EDHF). Hydrogen sulfide (H2S) is a prominent EDRF, since mice lacking its biosynthetic enzyme, cystathionine γ-lyase (CSE), display pronounced hypertension with deficient vasorelaxant responses to acetylcholine. Objective The purpose of this study is to determine if H2S is a major physiologic EDHF. Methods and Results We now show that H2S is a major EDHF, as in blood vessels of CSE deleted mice hyperpolarization is virtually abolished. H2S acts by covalently modifying (sulfhydrating) the ATP-sensitive potassium channel, as mutating the site of sulfhydration prevents H2S-elicited hyperpolarization. The endothelial intermediate conductance (IKCa) and small conductance (SKCa) potassium channels mediate in part the effects of H2S, as selective IKCa and SKCa channel inhibitors, charybdotoxin and apamin, inhibit glibenclamide insensitive H2S induced vasorelaxation. Conclusions H2S is a major EDHF that causes vascular endothelial and smooth muscle cell hyperpolarization and vasorelaxation by activating the ATP-sensitive, intermediate conductance and small conductance potassium channels through cysteine S-sulfhydration. As EDHF activity is a principal determinant of vasorelaxation in numerous vascular beds, drugs influencing H2S biosynthesis offer therapeutic potential. PMID:21980127

  12. Hydrogen sulfide and cell signaling: team player or referee?

    PubMed

    Hancock, J T; Whiteman, M

    2014-05-01

    Hydrogen sulfide (H2S) has been postulated to be the third gasotransmitter, and along with other reactive compounds such as reactive oxygen species (ROS) and nitric oxide (NO) it is thought to be a key signalling molecule. Enzymes which generate H2S, and remove it, have been characterised in both plants and animals and although it is inherently toxic to cells - inhibiting cytochrome oxidase for example - H2S is now being thought of as part of signal transduction pathways. But is it working as a signal in the sense usually seen for small signalling molecules, that is, produced when needed, perceived and leading to dedicated responses in cells? A look through the literature shows that H2S is involved in many stress responses, and in animals is implicated in the onset of many diseases, in both cases where ROS and NO are often involved. It is suggested here that H2S is not acting as a true signal, but through its interaction with NO and ROS metabolism is modulating such activity, keeping it in check unless strictly needed, and that H2S is acting as a referee to ensure NO and ROS metabolism is working properly. PMID:24607577

  13. Emerging role of hydrogen sulfide in colonic physiology and pathophysiology.

    PubMed

    Medani, Mekki; Collins, Danielle; Docherty, Neil G; Baird, Alan W; O'Connell, Patrick R; Winter, Des C

    2011-07-01

    Hydrogen sulfide (H?S) is a toxic gas that is now recognized as an important mediator of many physiological processes. In the colon, H?S is produced both endogenously and by naturally occurring sulfate-reducing bacteria (SRB). The full arrays of its effects in the gastrointestinal tract are still being elucidated, but they range from motility to carcinogenesis. We examined the evidence relating to H?S as a modulator of colonic function and disease. H?S is implicated in modulation of colonic compliance through its action on smooth muscle. There is also evidence linking H?S to colonic nociception, inflammatory bowel disease (IBD), and colorectal cancer. The exact mechanisms and pathways by which H?S exerts its multitude of effects are not yet fully understood, but its involvement in physiological and pathophysiological conditions of the colon is becoming evident. Elucidating the intricate effects of H?S in the colon and understanding the exact nature of its interactions with the colon makes pharmacological modulation of H?S production and metabolism potential targets for treatment of a multitude of colonic conditions in the future. PMID:21674719

  14. Neuroprotective effects of hydrogen sulfide and the underlying signaling pathways.

    PubMed

    Chen, Wen-Lin; Niu, Ying-Ying; Jiang, Wei-Zheng; Tang, Hui-Lan; Zhang, Chong; Xia, Qi-Ming; Tang, Xiao-Qing

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenously produced gas that represents a novel third gaseous signaling molecule, neurotransmitter and cytoprotectant. Cystathionine ?-synthase (CBS), cystathionine ?-lyase (CSE), 3-mercaptopyruvate sulfur transferase with cysteine aminotransferase (3-MST/CAT) and 3-mercaptopyruvate sulfur transferase with d-amino acid oxidase (3-MST/DAO) pathways are involved in the generation of endogenous H2S despite the ubiquitous or restricted distribution of those enzymes. CBS, 3-MST/CAT and 3-MST/DAO can be found in the brain, while CSE is widely located in other organs. There also exist up-taking or recycling and scavenging mechanisms in H2S metabolism to maintain its persistence for physiological function. In recent years, investigating the role that H2S plays in the central nervous system and cardiovascular system has always been a hotspot. To date, effects of H2S are at least partially verified in multiple animal models or neuron cell lines of Alzheimer's disease, Parkinson's disease, cerebral ischemia, major depression disorders and febrile seizure, although subsequent studies are still badly needed. This article presents an overview of current knowledge of H2S focusing on its neuroprotective effects and corresponding signaling pathways, together with connections to potential therapeutic strategies in the clinic. PMID:25528761

  15. Hydrogen sulfide gas has cell growth regulatory role.

    PubMed

    Baskar, Rajamanickam; Bian, Jinsong

    2011-04-10

    Hydrogen sulfide (H(2)S) has been classified as a third novel gasotransmitter signaling molecule alongside nitric oxide and carbon monoxide. H(2)S rapidly travels through the cell membranes without using any specific receptors/transporters and signaling intracellular proteins. Recently, it has been shown that H(2)S induces DNA damage and alter cell cycle in various mammalian cells. Endogenously produced or exogenously treated H(2)S has a role in the accumulation or proliferation of cells and further may provide for development of a novel therapeutic approach in conditions associated with uncontrolled cell growth. However, the potential biological and clinical significance of H(2)S are subject of intense debate in recent years and despite considerable progress in our understanding about H(2)S, much still needs to be learned about their production at the site of tissue injury and its downstream signaling pathways on cell growth. Here, we provide an overview of the recent findings on its role in DNA damage/repair and cell growth followed by its potential translational implications. PMID:21300051

  16. Endogenous hydrogen sulfide production is essential for dietary restriction benefits.

    PubMed

    Hine, Christopher; Harputlugil, Eylul; Zhang, Yue; Ruckenstuhl, Christoph; Lee, Byung Cheon; Brace, Lear; Longchamp, Alban; Trevio-Villarreal, Jose H; Mejia, Pedro; Ozaki, C Keith; Wang, Rui; Gladyshev, Vadim N; Madeo, Frank; Mair, William B; Mitchell, James R

    2015-01-15

    Dietary restriction (DR) without malnutrition encompasses numerous regimens with overlapping benefits including longevity and stress resistance, but unifying nutritional and molecular mechanisms remain elusive. In a mouse model of DR-mediated stress resistance, we found that sulfur amino acid (SAA) restriction increased expression of the transsulfuration pathway (TSP) enzyme cystathionine ?-lyase (CGL),resulting in increased hydrogen sulfide (H2S) production and protection from hepatic ischemia reperfusion injury. SAA supplementation, mTORC1 activation, or chemical/genetic CGL inhibition reduced H2S production and blocked DR-mediated stress resistance. Invitro, the mitochondrial protein SQR was required for H2S-mediated protection during nutrient/oxygen deprivation. Finally, TSP-dependent H2S production was observed in yeast, worm, fruit fly, and rodent models of DR-mediated longevity. Together, these data are consistent with evolutionary conservation of TSP-mediated H2S as a mediator ofDR benefits with broad implications for clinical translation. PAPERFLICK: PMID:25542313

  17. Fatal accidental hydrogen sulfide poisoning: a domestic case.

    PubMed

    Sastre, Caroline; Baillif-Couniou, Valrie; Kintz, Pascal; Cirimele, Vincent; Bartoli, Christophe; Christia-Lotter, Marie-Amandine; Piercecchi-Marti, Marie-Dominique; Leonetti, Georges; Pelissier-Alicot, Anne-Laure

    2013-01-01

    Hydrogen sulfide (H(2)S) poisonings are classically reported in occupational settings. We describe an unusual domestic case of fatal acute poisoning by H(2)S inhalation. A mother and her infant daughter were found dead in the kitchen of their home. The emergency medical team described a strong smell of rotten eggs, suggesting acute H(2)S poisoning. Autopsies revealed only multiorgan congestion. H(2) S was measured in blood and lung tissue samples by gas chromatography/mass spectrometry. Body fluids were negative, but H(2) S was found in the lungs of both the mother and the child at concentrations of 1.46 and 1.92 mg/kg, respectively, concentrations described in the literature as potentially lethal. Expert surveys of the premises suggested a complex mechanism involving both defective maintenance of the pipes and drains of the building and faulty assembly of the sink siphon, which led to stagnation of waste water and formation of a pocket of H(2)S. PMID:23126240

  18. Hydrogen Sulfide Induced Disruption of Na+ Homeostasis in the Cortex

    PubMed Central

    Chao, Dongman; He, Xiaozhou; Yang, Yilin; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H.; Xia, Ying

    2012-01-01

    Maintenance of ionic balance is essential for neuronal functioning. Hydrogen sulfide (H2S), a known toxic environmental gaseous pollutant, has been recently recognized as a gasotransmitter involved in numerous biological processes and is believed to play an important role in the neural activities under both physiological and pathological conditions. However, it is unclear if it plays any role in maintenance of ionic homeostasis in the brain under physiological/pathophysiological conditions. Here, we report by directly measuring Na+ activity using Na+ selective electrodes in mouse cortical slices that H2S donor sodium hydrosulfide (NaHS) increased Na+ influx in a concentration-dependent manner. This effect could be partially blocked by either Na+ channel blocker or N-methyl-D-aspartate receptor (NMDAR) blocker alone or almost completely abolished by coapplication of both blockers but not by non-NMDAR blocker. These data suggest that increased H2S in pathophysiological conditions, e.g., hypoxia/ischemia, potentially causes a disruption of ionic homeostasis by massive Na+ influx through Na+ channels and NMDARs, thus injuring neural functions. Activation of delta-opioid receptors (DOR), which reduces Na+ currents/influx in normoxia, had no effect on H2S-induced Na+ influx, suggesting that H2S-induced disruption of Na+ homeostasis is resistant to DOR regulation and may play a major role in neuronal injury in pathophysiological conditions, e.g., hypoxia/ischemia. PMID:22474073

  19. Hydrogen Sulfide: A Therapeutic Candidate for Fibrotic Disease?

    PubMed Central

    Song, Kai; Li, Qian; Yin, Xiao-Ya; Lu, Ying; Liu, Chun-Feng; Hu, Li-Fang

    2015-01-01

    Fibrotic diseases including chronic kidney disease, liver cirrhosis, idiopathic pulmonary fibrosis, and chronic disease account for 45% mortality in the developed countries and pose a great threat to the global health. Many great targets and molecules have been reported to be involved in the initiation and/or progression of fibrosis, among which inflammation and oxidative stress are well-recognized modulation targets. Hydrogen sulfide (H2S) is the third gasotransmitter with potent properties in inhibiting inflammation and oxidative stress in various organs. Recent evidence suggests that plasma H2S level is decreased in various animal models of fibrotic diseases and supplement of exogenous H2S is able to ameliorate fibrosis in the kidney, lung, liver, and heart. This leads us to propose that modulation of H2S production may represent a promising therapeutic venue for the treatment of a variety of fibrotic diseases. Here, we summarize and discuss the current data on the role and underlying mechanisms of H2S in fibrosis diseases related to heart, liver, kidney, and other organs. PMID:26078807

  20. Biofiltration of hydrogen sulfide by Sulfolobus metallicus at high temperatures.

    PubMed

    Morales, M; Silva, J; Morales, P; Gentina, J C; Aroca, G

    2012-01-01

    Biofiltration of reduced sulfur compounds such as hydrogen sulfide has been mainly applied to emissions at mild temperatures (25 to 35 °C). However, an important number of industrial gaseous emission containing sulfur compounds, from diverse industrial sectors (petroleum refinery, cellulose production, smelting, rendering plants and food industries) are emitted at temperatures over 50 °C. Most of the studies on thermophilic systems report that a higher elimination capacity can be obtained at elevated temperature, allowing the design of smaller equipment for the same loading rate than that required for removing the same load under mesophilic conditions. A biotrickling filter inoculated with Sulfolobus metallicus, which operates at three different residence times, 60, 80 and 120 s, and two different temperatures (45 and 55 °C) for treating H(2)S is reported. The input loads of H(2)S were progressively increased from 0 to 100 gS/m(3). The aim of this study was to determine the capacity and ability of S. metallicus to oxidize H(2)S at high temperatures. The better removal capacity of H(2)S obtained was 37.1 ± 1.7 gS/m(3) h at 55 °C for a residence time of 120 s. The difference of the removal capacity of H(2)S between the two temperatures was 4 g/m(3) h on average of sulfur removal for the different residence times. PMID:22925869

  1. Physiological and pharmacological features of the novel gasotransmitter: Hydrogen sulfide

    PubMed Central

    Mancardi, Daniele; Penna, Claudia; Merlino, Annalisa; Del Soldato, Piero; Wink, David A.; Pagliaro, Pasquale

    2012-01-01

    Hydrogen sulfide (H2S) has been known for hundreds of years because of its poisoning effect. Once the basal bio-production became evident its pathophysiological role started to be investigated in depth. H2S is a gas that can be formed by the action of two enzymes, cystathionine gamma-lyase and cystathionine beta-synthase, both involved in the metabolism of cysteine. It has several features in common with the other two well known “gasotransmitters” (nitric oxide and carbon monoxide) in the biological systems. These three gasses share some biological targets; however, they also have dissimilarities. For instance, the three gases target heme-proteins and open KATP channels; H2S as NO is an antioxidant, but in contrast to the latter molecule, H2S does not directly form radicals. In the last years H2S has been implicated in several physiological and pathophysiological processes such as long term synaptic potentiation, vasorelaxation, pro- and anti-inflammatory conditions, cardiac inotropism regulation, cardioprotection, and several other physiological mechanisms. We will focus on the biological role of H2S as a molecule able to trigger cell signaling. Our attention will be particularly devoted on the effects in cardiovascular system and in cardioprotection. We will also provide available information on H2S-donating drugs which have so far been tested in order to conjugate the beneficial effect of H2S with other pharmaceutical properties. PMID:19285949

  2. Hydrogen sulfide improves the endothelial dysfunction in renovascular hypertensive rats.

    PubMed

    Xue, H; Zhou, S; Xiao, L; Guo, Q; Liu, S; Wu, Y

    2015-01-01

    As a novel gasotransmitter, hydrogen sulfide (H(2)S) has vasodilating and antihypertensive effects in cardiovascular system. Thus, we hypothesized that H(2)S might have beneficial effects on thoracic endothelial function in two-kidney one-clip (2K1C) rats, a model of renovascular hypertension. Sodium hydrosulfide (NaHS, 56 micromol/kg/day) was administrated intra-peritoneally from the third day after the 2K1C operation. Along with the development of hypertension, the systolic blood pressure (SBP) was measured before the operation and each week thereafter. The oxidative stress was determined by measurement of malondialdehyde (MDA) concentration, superoxide dismutase (SOD) activity and protein expression of oxidative stress-related proteins (AT(1)R, NADPH oxidase subunits). Acetylcholine (ACh)-induced vasorelaxation and angiotensin II (Ang II)-induced vasocontraction were performed on isolated thoracic aorta. The SBP was significantly increased from the first week after operation, and was lowered by NaHS. NaHS supplementation ameliorated endothelial dysfunction. The protein expression of oxidative stress-related proteins were downregulated, while SOD activity upregulated. In conclusion, improvement of endothelial function is involved in the antihypertensive mechanism of H(2)S. The protective effect of H(2)S is attributable to suppression of vascular oxidative stress that involves inhibition of Ang II-AT(1)R action, downregulation of oxidases, as well as upregulation of antioxidant enzyme. PMID:25804097

  3. Carbamoylation abrogates the antioxidant potential of hydrogen sulfide.

    PubMed

    Praschberger, Monika; Hermann, Marcela; Laggner, Christian; Jirovetz, Leopold; Exner, Markus; Kapiotis, Stylianos; Gmeiner, Bernhard M K; Laggner, Hilde

    2013-11-01

    Hydrogen sulfide (H2S) has been identified as the third gasotransmitter. Beside its role as signaling molecule in the cardiovascular and nervous system the antioxidant and cyto-protective properties of H2S have gained much attention. In the present study we show that cyanate, an uremic toxin which is found in abundant concentration in sera of patients suffering from chronic kidney disease (CKD), can abrogate the antioxidant and cytoprotective activity of H2S via S-carbamoylation reaction, a reaction that previously has only been shown to have a physiological effect on cysteine groups, but not on H2S. Carbamoylation strongly inhibited the free radical scavenging (ABTS(+) and alkylperoxyl ROO()) properties of H2S. The extent of intracellular ROS formation induced by ROO() was diminished by H2S whereas carbamoylation counteracted the protective effect. Reagent HOCl was rapidly inactivated by H2S in contrast to the carbamoylated compound. Protein modification by HOCl was inhibited by H2S but carbamoylation significantly reduced the effect. Thus, S-carbamoylation of low molecular weight thiols by abrogating their antioxidant potential may contribute to the higher oxidative stress observed in CKD. PMID:23896375

  4. Inhaled Hydrogen Sulfide Prevents Endotoxin-Induced Systemic Inflammation and Improves Survival by Altering Sulfide Metabolism in Mice

    PubMed Central

    Tokuda, Kentaro; Kida, Kotaro; Marutani, Eizo; Crimi, Ettore; Bougaki, Masahiko; Khatri, Ashok; Kimura, Hideo

    2012-01-01

    Abstract Aims: The role of hydrogen sulfide (H2S) in endotoxin (lipopolysaccharide [LPS])-induced inflammation is incompletely understood. We examined the impact of H2S breathing on LPS-induced changes in sulfide metabolism, systemic inflammation, and survival in mice. Results: Mice that breathed air alone exhibited decreased plasma sulfide levels and poor survival rate at 72?h after LPS challenge. Endotoxemia markedly increased alanine aminotransferase (ALT) activity and nitrite/nitrate (NOx) levels in plasma and lung myeloperoxidase (MPO) activity in mice that breathed air. In contrast, breathing air supplemented with 80?ppm of H2S for 6?h after LPS challenge markedly improved survival rate compared to mice that breathed air alone (p<0.05). H2S breathing attenuated LPS-induced increase of plasma ALT activity and NOx levels and lung MPO activity. Inhaled H2S suppressed LPS-induced upregulation of inflammatory cytokines, while it markedly induced anti-inflammatory interleukin (IL)-10 in the liver. Beneficial effects of H2S inhalation after LPS challenge were associated with restored sulfide levels and markedly increased thiosulfate levels in plasma. Increased thiosulfate levels after LPS challenge were associated with upregulation of rhodanese, but not cystathionine-?-lyase (CSE), in the liver. Administration of sodium thiosulfate dose-dependently improved survival after LPS challenge in mice. Innovation: By measuring changes in plasma levels of sulfide and sulfide metabolites using an advanced analytical method, this study revealed a critical role of thiosulfate in the protective effects of H2S breathing during endotoxemia. Conclusion: These observations suggest that H2S breathing prevents inflammation and improves survival after LPS challenge by altering sulfide metabolism in mice. Antioxid. Redox Signal. 17, 1121. PMID:22221071

  5. Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect

    Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

    2007-09-30

    The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

  6. Slush hydrogen liquid level system

    NASA Technical Reports Server (NTRS)

    Hamlet, J. F.; Adams, R. G.

    1972-01-01

    A discrete capacitance liquid level system developed is specifically for slush hydrogen, but applicable to LOX, LN2, LH2, and RP1 without modification is described. The signal processing portion of the system is compatible with conventional liquid level sensors. Compatibility with slush hydrogen was achieved by designing the sensor with adequate spacing, while retaining the electrical characteristics of conventional sensors. Tests indicate excellent stability of the system over a temperature range of -20 C to 70 C for the circuit and to cryogenic temperatures of the sensor. The sensor was tested up to 40 g's rms random vibration with no damage to the sensor. Operation with 305 m of cable between the sensor and signal processor was demonstrated. It is concluded that this design is more than adequate for most flight and ground applications.

  7. Mobile measurement of methane and hydrogen sulfide at natural gas production site fence lines in the Texas Barnett Shale.

    PubMed

    Eapi, Gautam R; Sabnis, Madhu S; Sattler, Melanie L

    2014-08-01

    Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations > 3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations > 4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide. Implications: Information regarding air emissions from shale gas production is important given the recent increase in number of wells in various regions in the United States. Methane, the primary natural gas constituent, is a greenhouse gas; hydrogen sulfide, which can be present in gas condensate, is an odor-causing compound. This study surveyed wells representing one-third of the natural gas production volume in the Texas Barnett Shale and identified the percent of sites that warrant further study due to their fence line methane and hydrogen sulfide concentrations. PMID:25185395

  8. Dynamics of Withdrawal and Backflow of Sulfide Liquids and the Formation of Magmatic Ni-Cu-PGE Sulfide Deposits: Theory and Analogue Modeling

    NASA Astrophysics Data System (ADS)

    Saumur, B. M.; Cruden, A. R.

    2012-12-01

    Sulfide liquids precipitated from silicate magmas after sulfide saturation represent a volumetrically small portion of magmatic systems, but are responsible for the formation of orthomagmatic Ni-Cu-PGE sulfide deposits. Compared to silicate melts, immiscible magmatic sulfide liquids have lower viscosities (by 1 to 3 orders of magnitude), higher densities ( >1500 kg/m3 higher; also significantly higher than surrounding crust) and lower solidus temperatures (>150C lower). These properties hinder the withdrawal of sulfide liquid from magma staging chambers and its ascent to higher structural levels, and allow for late-stage mobility and downward percolation along grain boundaries and fractures within wall rocks. Prior to emplacement towards higher crustal levels, sulfide liquid will have a tendency to accumulate and pond at the bottom of staging chambers. Later mobilization and upward or lateral withdrawal of sulfide can occur by viscous entrainment within relatively buoyant (mafic) magma. Analytical solutions (e.g., Blake and Ivey, 1986, JVGR, 27, 153-178) applied to the low viscosities, high densities and the likely relatively high volumetric flow rates (Q) in mafic melt-sulfide liquid systems predicts that significant draw-up of sulfide liquid within mafic magmas can occur at high, yet realistic flow rates (10-1000 m3/s), at reasonable Reynolds (>1000) and Weber numbers (0.07-700). At lower Q and Re draw up is hindered by interfacial tension, as indicated by the low capillary numbers of the system. We evaluate the dynamics of withdrawal and entrainment of sulfide liquid using analogue models scaled to mafic-sulfide system, focusing on flow rates and the viscosity and density ratios between sulfide and mafic magmas, in order to further explore the conditions under which sulfide liquids can be effectively entrained to promote the generation of deposits elsewhere in the magma system. The dynamics of sulfide percolation are analogous to the behavior of dense non-aqueous phase liquids (DNAPL). In fractured systems sulfide backflow is strongly controlled by the column height of the dense liquid. Because dense fluids flow downwards, this column generates a higher vertical body force if the network of down-flowing fluid remains interconnected. To enter a fracture, the fluid must overcome a capillary pressure which is inversely proportional to the width of a fracture; thinner fracture widths can be intruded as a body of dense fluid percolates downwards. Such a process, along with late stage mobility of sulfide liquid, could explain the presence of thin (cm to m sized) massive sulfide injections into wall rocks observed at Ni-Cu deposits such as Voisey's Bay (Labrador, CAN), Eagle (Michigan, USA), and Sudbury's late offset dykes.

  9. Hydrogen sulfide gas emission under turbulent conditions - an experimental approach for free-fall drops.

    PubMed

    Matias, N M; Matos, J S; Ferreira, F

    2014-01-01

    Odor nuisance and sulfide corrosion in sewers carrying septic wastewater are accelerated at points of turbulence such as drops in manholes, but accurate methods or empirical expressions to evaluate the gas stripping rate at those particular sites are still missing. With the aim of improving the current knowledge on the influence of free-fall drops on the release of hydrogen sulfide gas, an experimental set-up was built allowing different free-fall drops heights and flows. Three types of experiments were carried out: reaeration tests without sulfide; sulfide oxidation tests; and hydrogen sulfide release tests. With the increase of the free-fall drop height or of the flow, a higher rate of air-to-water mass oxygen transfer was observed. Results regarding sulfide oxidation tests with reaeration through the free-fall have shown that the oxidation rate was correlated with flow. In the hydrogen sulfide release tests, the maximum concentration in the atmosphere reached 500 ppm. Results also showed that increasing the flow rate decreased the time at which the maximum concentrations in the atmosphere were observed. PMID:24473293

  10. Intermittent control procedures for the Geysers hydrogen sulfide emission abatement

    SciTech Connect

    Buick, B.D.; Mooney, M.L.

    1984-01-01

    Pacific Gas and Electric Company (PG and E) operates the world's largest geothermal steam electric power generation facility, currently about 1.140 megawatts (Mw). This facility is located about 80 miles north of San Francisco, California and is within a region referred to as the Known Geothermal Resource Area (KGRA). Pollutants resulting from this method of electric power generation are due to impurities in the geothermal steam. A major contaminate in the steam is hydrogen sulfide (H/sub 2/S), a regulated pollutant in California. The ambient air quality standard (AAQS) for this pollutant in California is 0.03 parts per million (ppM) averaged over one hour. H/sub 2/S is an invisible, unpleasant smelling gas present in varying concentrations in the geothermal steam. Its odor has been compared to the smell of rotten eggs. Since PG and E is increasingly relying on this source of electrical power generation, it has committed millions of dollars to the development, testing, acquisition, and installation of abatement equipment to reduce H/sub 2/S emissions during the past ten years. In order to reduce the number of exceeds of the AAQS during this developmental period, a predictive model was needed for interim abatement purposes. Most of the high hourly H/sub 2/S values occur with meteorological conditions having poor ventilation resulting from a combination of low wind speed and reduced mixing layer depths. This weather condition is most common during the months of June through October in California. A predictive model was developed from three years of hourly H/sub 2/S measurements of 0.03 ppM or greater in populated areas downwind of the generation facility and from observations of associated meteorological data.

  11. Biofiltration for control of carbon disulfide and hydrogen sulfide vapors

    SciTech Connect

    Fucich, W.J.; Yang, Y.; Togna, A.P.; Alibeckoff, D.

    1997-12-31

    A full-scale biofiltration system has been installed to control carbon disulfide (CS{sub 2}) and hydrogen sulfide (H{sub 2}S) vapor emissions at Nylonge Corporation (Nylonge), a cellulose sponge manufacturing facility in Elyria, Ohio. Both CS{sub 2} and H{sub 2}S are toxic and odorous. In addition, the US Environmental Protection Agency (EPA) has classified CS{sub 2} as one of the 189 hazardous air pollutants listed under Title 3 of the 1990 Clean Air Act Amendments. Nylonge evaluated several technologies to control CS{sub 2} and H{sub 2}S vapor emissions. After careful consideration of both removal efficiency requirements and cost, Nylonge selected biological treatment as the best overall technology for their application. A biological based technology has been developed to effectively degrade CS{sub 2} and H{sub 2}S vapors. Biofiltration is a process that aerobically converts particular vapor phase compounds into CO{sub 2}, biomass, and water vapor. In this process, microorganisms, in the form of a moistened biofilm layer, immobilized on an organic packing material, such as compost, peat, wood chips, etc., are used to catalyze beneficial chemical reactions. As a contaminated vapor stream passes through the biofilter bed, the contaminants are transferred to the biofilm and are degraded by the microorganisms. This paper describes the CS{sub 2} and H{sub 2}S biofiltration process and the full-scale biofilter system installed at Nylonge`s facility. The system was started in October of 1995, and is designed to treat a 30,000 CFM exhaust stream contaminated with CS{sub 2} and H{sub 2}S vapors.

  12. Hydrogen sulfide promotes calcium uptake in larval zebrafish.

    PubMed

    Kwong, Raymond W M; Perry, Steve F

    2015-07-01

    Hydrogen sulfide (H2S) can act as a signaling molecule for various ion channels and/or transporters; however, little is known about its potential involvement in Ca(2+) balance. Using developing zebrafish (Danio rerio) as an in vivo model system, the present study demonstrated that acute exposure to H2S donors increased Ca(2+) influx at 4 days postfertilization, while chronic (3-day) exposure caused a rise in whole body Ca(2+) levels. The mRNA expression of Ca(2+)-transport-related genes was unaffected by H2S exposure, suggesting that posttranscriptional modifications were responsible for the altered rates of Ca(2+) uptake. Indeed, treatment of fish with the protein kinase A inhibitor H-89 abolished the H2S-mediated stimulation of Ca(2+) influx, suggesting that H2S increased Ca(2+) influx by activating cAMP-protein kinase A pathways. Cystathionine ?-synthase (CBS) and cystathionine ?-lyase (CSE) are two key enzymes in the endogenous synthesis of H2S. Using an antisense morpholino knockdown approach, we demonstrated that Ca(2+) influx was reduced in CBS isoform b (CBSb)- but not in CSE-deficient fish. Interestingly, the reduction in Ca(2+) influx in CBSb-deficient fish was observed only in fish that were acclimated to low-Ca(2+) water (i.e., 25 ?M Ca(2+); control: 250 ?M Ca(2+)). Similarly, mRNA expression of cbsb but not cse was increased in fish acclimated to low-Ca(2+) water. Results from whole-mount immunohistochemistry further revealed that CBSb was expressed in Na(+)-K(+)-ATPase-rich cells, which are implicated in Ca(2+) uptake in zebrafish larvae. Collectively, the present study suggests a novel role for H2S in promoting Ca(2+) influx, particularly in a low-Ca(2+) environment. PMID:25948733

  13. Hydrogen Sulfide Mediates Cardioprotection Through Nrf2 Signaling

    PubMed Central

    Calvert, John W.; Jha, Saurabh; Gundewar, Susheel; Elrod, John W.; Ramachandran, Arun; Pattillo, Christopher B.; Kevil, Christopher G.; Lefer, David J.

    2009-01-01

    Rationale The recent emergence of hydrogen sulfide (H2S) as a potent cardioprotective signaling molecule necessitates the elucidation of its cytoprotective mechanisms. Objective The current study evaluated potential mechanisms of H2S-mediated cardioprotection using an in vivo model of pharmacological preconditioning (PC). Methods and Results H2S (100 ?g/kg), or vehicle was administered to mice via an intravenous injection 24 hr prior to myocardial ischemia. Treated and untreated mice were then subjected to 45 min of myocardial ischemia followed by reperfusion for up to 24 hr, during which time the extent of myocardial infarction was evaluated, circulating troponin-I levels were measured, and the degree of oxidative stress was evaluated. In separate studies myocardial tissue was collected from treated and untreated mice during the early (30 min and 2hr) and late (24 hr) PC periods to evaluate potential cellular targets of H2S. Initial studies revealed that H2S provided profound protection against ischemic injury as evidenced by significant decreases in infarct size, circulating troponin-I levels, and oxidative stress. During the early PC period H2S increased the nuclear localization of Nrf2, a transcription factor that regulates the gene expression of a number of antioxidants, and increased the phosphorylation of PKC? and STAT-3. During the late PC period, H2S increased the expression of antioxidants (HO-1 and Trx1), increased the expression of HSP90, HSP70, Bcl-2, Bcl-xL, and COX-2 and also inactivated the pro-apoptogen Bad. Conclusions These results reveal that the cardioprotective effects of H2S are mediated in large part by a combination of antioxidant and anti-apoptotic signaling. PMID:19608979

  14. Hydrogen sulfide improves neural function in rats following cardiopulmonary resuscitation

    PubMed Central

    LIN, JI-YAN; ZHANG, MIN-WEI; WANG, JIN-GAO; LI, HUI; WEI, HONG-YAN; LIU, RONG; DAI, GANG; LIAO, XIAO-XING

    2016-01-01

    The alleviation of brain injury is a key issue following cardiopulmonary resuscitation (CPR). Hydrogen sulfide (H2S) is hypothesized to be involved in the pathophysiological process of ischemia-reperfusion injury, and exerts a protective effect on neurons. The aim of the present study was to investigate the effects of H2S on neural functions following cardiac arrest (CA) in rats. A total of 60 rats were allocated at random into three groups. CA was induced to establish the model and CPR was performed after 6 min. Subsequently, sodium hydrosulfide (NaHS), hydroxylamine or saline was administered to the rats. Serum levels of H2S, neuron-specific enolase (NSE) and S100β were determined following CPR. In addition, neurological deficit scoring (NDS), the beam walking test (BWT), prehensile traction test and Morris water maze experiment were conducted. Neuronal apoptosis rates were detected in the hippocampal region following sacrifice. After CPR, as the H2S levels increased or decreased, the serum NSE and S100β concentrations decreased or increased, respectively (P<0.0w. The NDS results of the NaHS group were improved compared with those of the hydroxylamine group at 24 h after CPR (P<0.05). In the Morris water maze experiment, BWT and prehensile traction test the animals in the NaHS group performed best and rats in the hydroxylamine group performed worst. At day 7, the apoptotic index and the expression of caspase-3 were reduced in the hippocampal CA1 region, while the expression of Bcl-2 increased in the NaHS group; and results of the hydroxylamine group were in contrast. Therefore, the results of the present study indicate that H2S is able to improve neural function in rats following CPR. PMID:26893650

  15. The Global Transcriptional Response of Fission Yeast to Hydrogen Sulfide

    PubMed Central

    Jia, Xu; He, Weizhi; Murchie, Alastair I. H.; Chen, Dongrong

    2011-01-01

    Background Hydrogen sulfide (H2S) is a newly identified member of the small family of gasotransmitters that are endogenous gaseous signaling molecules that have a fundamental role in human biology and disease. Although it is a relatively recent discovery and the mechanism of H2S activity is not completely understood, it is known to be involved in a number of cellular processes; H2S can affect ion channels, transcription factors and protein kinases in mammals. Methodology/Principal Findings In this paper, we have used fission yeast as a model organism to study the global gene expression profile in response to H2S by microarray. We initially measured the genome-wide transcriptional response of fission yeast to H2S. Through the functional classification of genes whose expression profile changed in response to H2S, we found that H2S mainly influences genes that encode putative or known stress proteins, membrane transporters, cell cycle/meiotic proteins, transcription factors and respiration protein in the mitochondrion. Our analysis showed that there was a significant overlap between the genes affected by H2S and the stress response. We identified that the target genes of the MAPK pathway respond to H2S; we also identified that a number of transporters respond to H2S, these include sugar/carbohydrate transporters, ion transporters, and amino acid transporters. We found many mitochondrial genes to be down regulated upon H2S treatment and that H2S can reduce mitochondrial oxygen consumption. Conclusion/Significance This study identifies potential molecular targets of the signaling molecule H2S in fission yeast and provides clues about the identity of homologues human proteins and will further the understanding of the cellular role of H2S in human diseases. PMID:22164259

  16. Chronic Ambient Hydrogen Sulfide Exposure and Cognitive Function

    PubMed Central

    Reed, Bruce R.; Crane, Julian; Garrett, Nick; Woods, David L.; Bates, Michael N.

    2014-01-01

    Background Exposures to hydrogen sulfide gas (H2S) have been inconclusively linked to a variety of negative cognitive outcomes. We investigated possible effects on cognitive function in an urban population with chronic, low-level exposure to H2S. Methods Participants were 1,637 adults, aged 18-65 years from Rotorua city, New Zealand, exposed to ambient H2S from geothermal sources. Exposures at homes and workplaces were estimated from data collected by summer and winter H2S monitoring networks across Rotorua in 2010/11. Metrics for H2S exposure at the time of participation and for exposure over the last 30 years were calculated. H2S exposure was modeled both as continuous variables and as quartiles of exposure covering the range of 0 64 ppb (0-88 ?g/m3). Outcomes were neuropsychological tests measuring visual and verbal episodic memory, attention, fine motor skills, psychomotor speed and mood. Associations between cognition and measures of H2S exposure were investigated with multiple regression, while covarying demographics and factors known to be associated with cognitive performance. Results The consistent finding was of no association between H2S exposure and cognition. Quartiles of H2S exposure had a small association with simple reaction time: higher exposures were associated with faster response times. Similarly, for digit symbol, higher H2S exposures tended to be marginally associated with better performance. Conclusion The results provide evidence that chronic H2S exposure, at the ambient levels found in and around Rotorua, is not associated with impairment of cognitive function. PMID:24548790

  17. Hydrogen sulfide inhibits Na+ uptake in larval zebrafish, Danio rerio.

    PubMed

    Kumai, Yusuke; Porteus, Cosima S; Kwong, Raymond W M; Perry, Steve F

    2015-04-01

    The present study investigated the role of hydrogen sulfide (H2S) in regulating Na(+) uptake in larval zebrafish, Danio rerio. Waterborne treatment of larvae at 4 days post-fertilization (dpf) with Na2S or GYY-4137 (chemicals known to generate H2S) significantly reduced Na(+) uptake. Exposure of larvae to water enriched with NaCl (1 mM NaCl) caused a pronounced reduction in Na(+) uptake which was prevented by pharmacological inhibition of cystathionine ?-synthase (CBS) or cystathionine ?-lyase (CSE), two key enzymes involved in the endogenous synthesis of H2S. Furthermore, translational gene knockdown of CSE and CBSb significantly increased the basal rate of Na(+) uptake. Waterborne treatment with Na2S significantly decreased whole-body acid excretion and reduced Na(+) uptake in larval zebrafish preexposed to acidic (pH 4.0) water (a condition shown to promote Na(+) uptake via Na(+)-H(+)-exchanger 3b, NHE3b). However, Na2S did not affect Na(+) uptake in larvae depleted of NHE3b-containing ionocytes (HR cells) after knockdown of transcription factor glial cell missing 2 (gcm2) in which Na(+) uptake occurs predominantly via Na(+)-Cl(-) co-transporter (NCC)-containing cells. These observations suggest that Na(+) uptake via NHE3b, but not NCC, is regulated by H2S. Whole-mount immunohistochemistry demonstrated that ionocytes expressing NHE3b also express CSE. These data suggests a physiologically relevant role of H2S as a mechanism to lower Na(+) uptake in zebrafish larvae, probably through its inhibitory action on NHE3b. PMID:24939700

  18. Hydrogen sulfide is an endogenous stimulator of angiogenesis.

    PubMed

    Papapetropoulos, Andreas; Pyriochou, Anastasia; Altaany, Zaid; Yang, Guangdong; Marazioti, Antonia; Zhou, Zongmin; Jeschke, Mark G; Branski, Ludwik K; Herndon, David N; Wang, Rui; Szab, Csaba

    2009-12-22

    The goal of the current study was to investigate the role of exogenous and endogenous hydrogen sulfide (H(2)S) on neovascularization and wound healing in vitro and in vivo. Incubation of endothelial cells (ECs) with H(2)S enhanced their angiogenic potential, evidenced by accelerated cell growth, migration, and capillary morphogenesis on Matrigel. Treatment of chicken chorioallantoic membranes (CAMS) with H(2)S increased vascular length. Exposure of ECs to H(2)S resulted in increased phosphorylation of Akt, ERK, and p38. The K(ATP) channel blocker glibenclamide or the p38 inhibitor SB203580 abolished H(2)S-induced EC motility. Since glibenclamide inhibited H(2)S-triggered p38 phosphorylation, we propose that K(ATP) channels lay upstream of p38 in this process. When CAMs were treated with H(2)S biosynthesis inhibitors dl-propylargylglycine or beta-cyano-L-alanine, a reduction in vessel length and branching was observed, indicating that H(2)S serves as an endogenous stimulator of the angiogenic response. Stimulation of ECs with vascular endothelial growth factor (VEGF) increased H(2)S release, while pharmacological inhibition of H(2)S production or K(ATP) channels or silencing of cystathionine gamma-lyase (CSE) attenuated VEGF signaling and migration of ECs. These results implicate endothelial H(2)S synthesis in the pro-angiogenic action of VEGF. Aortic rings isolated from CSE knockout mice exhibited markedly reduced microvessel formation in response to VEGF when compared to wild-type littermates. Finally, in vivo, topical administration of H(2)S enhanced wound healing in a rat model, while wound healing was delayed in CSE(-/-) mice. We conclude that endogenous and exogenous H(2)S stimulates EC-related angiogenic properties through a K(ATP) channel/MAPK pathway. PMID:19955410

  19. Is Hydrogen Sulfide-Induced Suspended Animation General Anesthesia?

    PubMed Central

    Li, Rosie Q.; McKinstry, Andrew R.; Moore, Jason T.; Caltagarone, Breanna M.; Eckenhoff, Maryellen F.; Eckenhoff, Roderic G.

    2012-01-01

    Hydrogen sulfide (H2S) depresses mitochondrial function and thereby metabolic rates in mice, purportedly resulting in a state of suspended animation. Volatile anesthetics also depress mitochondrial function, an effect that may contribute to their anesthetic properties. In this study, we ask whether H2S has general anesthetic properties, and by extension, whether mitochondrial effects underlie the state of anesthesia. We compared loss of righting reflex, electroencephalography, and electromyography in mice exposed to metabolically equipotent concentrations of halothane, isoflurane, sevoflurane, and H2S. We also studied combinations of H2S and anesthetics to assess additivity. Finally, the long-term effects of H2S were assessed by using the Morris water maze behavioral testing 2 to 3 weeks after exposures. Exposure to H2S decreases O2 consumption, CO2 production, and body temperature similarly to that of the general anesthetics, but fails to produce a loss of righting reflex or muscle atonia at metabolically equivalent concentrations. When combined, H2S antagonizes the metabolic effects of isoflurane, but potentiates the isoflurane-induced loss of righting reflex. We found no effect of prior H2S exposure on memory or learning. H2S (250 ppm), not itself lethal, produced delayed lethality when combined with subanesthetic concentrations of isoflurane. H2S cannot be considered a general anesthetic, despite similar metabolic suppression. Metabolic suppression, presumably via mitochondrial actions, is not sufficient to account for the hypnotic or immobilizing components of the anesthetic state. Combinations of H2S and isoflurane can be lethal, suggesting extreme care in the combination of these gases in clinical situations. PMID:22414854

  20. Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

    PubMed Central

    Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

    2008-01-01

    Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a doseresponse increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age ( SD) = 24.7 4.2; mean years of education = 16.5 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Doseresponse reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No doseresponse effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures. PMID:18197303

  1. Single Membrane Reactor Configuration for Separation of Hydrogen, Carbon Dioxide and Hydrogen Sulfide

    SciTech Connect

    Micheal Roberts; Robert Zabransky; Shain Doong; Jerry Lin

    2008-05-31

    The objective of the project was to develop a novel complementary membrane reactor process that can consolidate two or more downstream unit operations of a coal gasification system into a single module for production of a pure stream of hydrogen and a pure stream of carbon dioxide. The overall goals were to achieve higher hydrogen production efficiencies, lower capital costs and a smaller overall footprint than what could be achieved by utilizing separate components for each required unit process/operation in conventional coal-to-hydrogen systems. Specifically, this project was to develop a novel membrane reactor process that combines hydrogen sulfide removal, hydrogen separation, carbon dioxide separation and water-gas shift reaction into a single membrane configuration. The carbon monoxide conversion of the water-gas-shift reaction from the coal-derived syngas stream is enhanced by the complementary use of two membranes within a single reactor to separate hydrogen and carbon dioxide. Consequently, hydrogen production efficiency is increased. The single membrane reactor configuration produces a pure H{sub 2} product and a pure CO{sub 2} permeate stream that is ready for sequestration. This project focused on developing a new class of CO{sub 2}-selective membranes for this new process concept. Several approaches to make CO{sub 2}-selective membranes for high-temperature applications have been tested. Membrane disks using the technique of powder pressing and high temperature sintering were successfully fabricated. The powders were either metal oxide or metal carbonate materials. Experiments on CO{sub 2} permeation testing were also performed in the temperature range of 790 to 940 C for the metal carbonate membrane disks. However, no CO{sub 2} permeation rate could be measured, probably due to very slow CO{sub 2} diffusion in the solid state carbonates. To improve the permeation of CO{sub 2}, one approach is to make membranes containing liquid or molten carbonates. Several different types of dual-phase membranes were fabricated and tested for their CO{sub 2} permeation in reducing conditions without the presence of oxygen. Although the flux was quite low, on the order of 0.01-0.001 cc STP/cm{sup 2}/min, the selectivity of CO{sub 2}/He was almost infinite at temperatures of about 800 C. A different type of dual-phase membrane prepared by Arizona State University (ASU) was also tested at GTI for CO{sub 2} permeation. The measured CO{sub 2} fluxes were 0.015 and 0.02 cc STP/cm{sup 2}/min at 750 and 830 C, respectively. These fluxes were higher than the previous flux obtained ({approx}0.01 cc STP/cm{sup 2}/min) using the dual-phase membranes prepared by GTI. Further development in membrane development should be conducted to improve the CO{sub 2} flux. ASU has also focused on high temperature permeation/separation experiments to confirm the carbon dioxide separation capabilities of the dual-phase membranes with La{sup 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (LSCF6482) supports infiltrated with a Li/Na/K molten carbonate mixture (42.5/32.5/25.0 mole %). The permeation experiments indicated that the addition of O{sub 2} does improve the permeance of CO{sub 2} through the membrane. A simplified membrane reactor model was developed to evaluate the performance of the process. However, the simplified model did not allow the estimation of membrane transport area, an important parameter for evaluating the feasibility of the proposed membrane reactor technology. As a result, an improved model was developed. Results of the improved membrane reactor model show that the membrane shift reaction has promise as a means to simplify the production of a clean stream of hydrogen and a clean stream of carbon dioxide. The focus of additional development work should address the large area required for the CO{sub 2} membrane as identified in the modeling calculations. Also, a more detailed process flow diagram should be developed that includes integration of cooling and preheating feed streams as well as particulate removal so that steam and power generation could be optimized. For the tubular membranes that were fabricated by solution impregnation with metal carbonates, difficulties were encountered in removing the impurity salts that were trapped inside the porous support tube. The membrane tube would continue losing weight even after being heated up to 500 C in air and could not maintain its nonporous characteristics. This approach was therefore abandoned. Dual-phase membranes with molten carbonates were subsequently shown to have CO{sub 2} permeability in reducing conditions without the presence of oxygen; they were also tested for H{sub 2}S permeation. Permeation tests were conducted with a gas feed composition consisting of 33.6% CO{sub 2}, 8.4% He, 57.6% H{sub 2} and 0.4% H{sub 2}S at temperatures between 820 and 850 C and a pressure of 1 bar.

  2. Ammonium tetrathiomolybdate as a water-soluble and slow-release hydrogen sulfide donor.

    PubMed

    Xu, Shi; Yang, Chun-Tao; Meng, Fu-Hui; Pacheco, Armando; Chen, Li; Xian, Ming

    2016-03-15

    Ammonium tetrathiomolybdate (TTM) was found to be a slow hydrogen sulfide (H2S) releasing agent. Its H2S generation capability in aqueous solutions was confirmed by UV-vis and fluorescence assays. TTM also showed H2S-like cytoprotective effects in hydrogen peroxide (H2O2)-induced oxidative damage in HaCaT cells. PMID:26898812

  3. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must... CONTINENTAL SHELF Plans and Information Contents of Exploration Plans (ep) § 250.215 What hydrogen...

  4. Anoxie transformations of radiolabeled hydrogen sulfide in marine and freshwater sediments

    NASA Astrophysics Data System (ADS)

    Elsgaard, Lars; Jrgensen, Bo Barker

    1992-06-01

    Radiolabeled hydrogen sulfide (H 35S -) was used to trace the anoxic sulfur transformations in marine and freshwater sediment slurries. Time course studies consistently showed a rapid 35S 2O 3- formation and a progressive accumulation of 35SO 4- and thus indicated an anoxic sulfide oxidation to sulfate. Thiosulfate was partly turned over by oxidation or disproportionation and was found to be an intermediate in the 35SO 4- formation. The results demonstrate that oxidative and reductive sulfur cycling may occur simultaneously in marine and freshwater sediments. When added as exogenous oxidant, nitrate (NO 3-) stimulated the anoxic sulfide oxidation to sulfate. Ferric iron, added in the form of lepidocrocite (?-FeOOH), caused the precipitation of iron sulfides and only partial sulfide oxidation to pyrite and elemental sulfur.

  5. Cystathionine ?-synthase-derived hydrogen sulfide is involved in human malignant hyperthermia.

    PubMed

    Vellecco, Valentina; Mancini, Antonio; Ianaro, Angela; Calderone, Vincenzo; Attanasio, Chiara; Cantalupo, Anna; Andria, Barbara; Savoia, Gennaro; Panza, Elisabetta; Di Martino, Antonietta; Cirino, Giuseppe; Bucci, Mariarosaria

    2016-01-01

    Hydrogen sulfide is an endogenous gasotransmitter and its mechanism of action involves activation of ATP-sensitive K(+) channels and phosphodiesterase inhibition. As both mechanisms are potentially involved in malignant hyperthermia (MH), in the present study we addressed the involvement of the L-cysteine/hydrogen sulfide pathway in MH. Skeletal muscle biopsies obtained from 25 MH-susceptible (MHS) and 56 MH-negative (MHN) individuals have been used to perform the invitro contracture test (IVCT). Quantitative real-time PCR (qPCR) and Western blotting studies have also been performed. Hydrogen sulfide levels are measured in both tissue samples and plasma. In MHS biopsies an increase in cystathionine ?-synthase (CBS) occurs, as both mRNA and protein expression compared with MHN biopsies. Hydrogen sulfide biosynthesis is increased in MHS biopsies (0.1280.12 compared with 0.9430.13 nmol/mg of protein per min for MHN and MHS biopsies, respectively; P<0.01). Addition of sodium hydrosulfide (NaHS) to MHS samples evokes a response similar, in the IVCT, to that elicited by either caffeine or halothane. Incubation of MHN biopsies with NaHS, before caffeine or halothane challenge, switches an MHN to an MHS response. In conclusion we demonstrate the involvement of the L-cysteine/hydrogen sulfide pathway in MH, giving new insight into MH molecular mechanisms. This finding has potential implications for clinical care and could help to define less invasive diagnostic procedures. PMID:26460077

  6. Distributed fiber optic chemical sensor for hydrogen sulfide and chlorine detection

    NASA Astrophysics Data System (ADS)

    Mukamal, Harold; Cordero, Steven R.; Ruiz, David; Beshay, Manal; Lieberman, Robert A.

    2005-11-01

    Fiber optic sensors having their entire length as the sensing elements for chlorine or hydrogen sulfide are reported here. The chlorine fiber consists of a silica core and a chlorine-sensitive cladding, and the hydrogen sulfide fiber has a hydrogen sulfide sensitive cladding. Upon exposure to the corresponding challenge gas, the cladding very rapidly changes color resulting in attenuation of the light throughput of the fiber. A one-meter portion of the chlorine sensor fiber responds to 10 ppm chlorine in 20 seconds and to 1 ppm in several minutes. The attenuation after 10 minutes of exposure is very high, and is dependant on both chlorine concentration and fiber length. A ten-meter portion of the hydrogen sulfide sensor fiber responds to 100 ppm hydrogen sulfide in 30 seconds and to 10 ppm in 1 minute. The high sensitivity suggests that the propagating modes of the light interact strongly with the cladding, and that these interactions are massively increased (Beers Law) due to the extended sensor length. This approach will supersede the current method of having a collection of point-detectors to cover large areas.

  7. Conversion of ammonia into hydrogen and nitrogen by reaction with a sulfided catalyst

    DOEpatents

    Matthews, Charles W.

    1977-01-01

    A method is provided for removing ammonia from the sour water stream of a coal gasification process. The basic steps comprise stripping the ammonia from the sour water; heating the stripped ammonia to a temperature from between 400.degree. to 1,000.degree. F; passing the gaseous ammonia through a reactor containing a sulfided catalyst to produce elemental hydrogen and nitrogen; and scrubbing the reaction product to obtain an ammonia-free gas. The residual equilibrium ammonia produced by the reactor is recycled into the stripper. The ammonia-free gas may be advantageously treated in a Claus process to recover elemental sulfur. Iron sulfide or cobalt molybdenum sulfide catalysts are used.

  8. Methanol and hydrogen sulfide in comet P/Halley

    NASA Technical Reports Server (NTRS)

    Eberhardt, P.; Meier, R.; Krankowsky, D.; Hodges, R. R.

    1994-01-01

    The Neutral Mass Spectrometer on the Giotto spacecraft measured the gas and ion composition in the coma of comet P/Halley. A detailed model of the ion chemistry inside the contact surface located at 4660 km is used to interpret the measured ion desnity profiles in the 32 to 35 amu/e mass range. The masses 33 and 35 amu/e are dominated by the protonated methanol and hydrogen sulfide ions CH3OH2(+) and H3S(+). Both profiles are essentially compatible with CH3OH and H2S originating from the nucleus only. The production rates relative to water are Y(CH3OH) = Q(CH3OH)/Q(H2O) = 1.7% and Y(H2S) = 0.41%. Our Y(CH3OH) agrees well with a determination from IR spectra obtained about 6 weeks after the Giotto encounter with P/Halley. In 7 other comets IR and microwave observations give Y(CH3OH) values between about 0.7 and 6%, indicating that the methanol abundance shows a strong variability from comet to comet. In three other comets Y(H2S) values between 0.2 and 0.5% have been reported. In addition to H2S(+), only ions containing minor isotopes of H, C, O and S contribute to mass 34 amu/e (e.g. (34)S(+), (13)CH3OH2(+), CH4DO(+)). These contributions can be calculated from the measured densities of the ions containing the major isotopes and the H2S(+) contribution from the measured H3S(+) density. From mass 34 amu/e we can also derive an upper limit of 1% for the abundance of deuterated methanol. This limit is at most marginally compatible with a direct interstellar origin of the CH3OH in P/Halley as the measured interstellar abundance of deuterated methanol is 1 to 6%.

  9. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco.

    PubMed

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild; Nielsen, Asbjrn Haaning

    2015-11-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit with some uncertainty. It was concluded that the model could be applied for the purpose in mind. PMID:26564586

  10. Analysis of hypochlorite process for removal of hydrogen sulfide from geothermal gases

    SciTech Connect

    Not Available

    1980-04-01

    Sodium hypochlorite reacts readily with hydrogen sulfide to convert the sulfide ion into free sulfur in a neutral or acid solution and to the sulfate ion in an alkaline solution. Sodium hypochlorite can be generated on site by processing geothermal brine in electrolytic cells. An investigation to determine if this reaction could be economically used to remove hydrogen sulfide from geothermal noncondensible gases is reported. Two processes, the LO-CAT Process and the Stretford Process, were selected for comparison with the hypochlorite process. Three geothermal reservoirs were considered for evaluation: Niland KGRA, Baca KGRA, and The Geysers KGRA. Because of the wide variation in the amount of hydrogen sulfide present at The Geysers, two different gas analyses were considered for treatment. Plants were designed to process the effluent noncondensible gases from a 10 MW/sub e/ geothermal power plant. The effluent gas from each plant was to contain a maximum hydrogen sulfide concentration of 35 ppb. Capital costs were estimated for each of the processes at each of the four sites selected. Operating costs were also calculated for each of the processes at each of the sites. The results of these studies are shown.

  11. A solid oxide fuel cell system fed with hydrogen sulfide and natural gas

    NASA Astrophysics Data System (ADS)

    Lu, Yixin; Schaefer, Laura

    Hydrogen sulfide (H 2S) occurs naturally in crude petroleum, natural gas, volcanic gases, hot springs, and some lakes. Hydrogen sulfide can also result as a by-product from industrial activities, such as food processing, coke ovens, paper mills, tanneries, and petroleum refineries. Sometimes, it is considered to be an industrial pollutant. However, hydrogen can be decomposed from H 2S and then used as fuel for a solid oxide fuel cell (SOFC). This paper presents an examination of a simple hydrogen sulfide and natural gas-fed solid oxide fuel cell system. The possibility of utilization of hydrogen sulfide as a feedstock in a solid oxide fuel cell is discussed. A system configuration of an SOFC combined with an external H 2S decomposition device is proposed, where a certain amount of natural gas is supplied to the SOFC. The exhaust fuel gas of the SOFC is after-burned with exhaust air from the SOFC, and the heat of the combustion gas is utilized in the decomposition of H 2S in a decomposition reactor (DR) to produce hydrogen to feed the SOFC. The products are electricity and industry-usable sulfur. Through a mass and energy balance, a preliminary thermodynamic analysis of this system is performed, and the system efficiency is calculated. Also in this paper, the challenges in creating the proposed configuration are discussed, and the direction of future work is presented.

  12. Methane and hydrogen sulfide emissions in UASB reactors treating domestic wastewater.

    PubMed

    Souza, C L; Chernicharo, C A L; Melo, G C B

    2012-01-01

    The release of CH(4) and H(2)S in UASB reactors was evaluated with the aim to quantify the emissions from the liquid surfaces (three-phase separator and settler compartment) and also from the reactor's discharge hydraulic structures. The studies were carried out in two pilot- (360 L) and one demo-scale (14 m(3)) UASB reactors treating domestic wastewater. As expected, the release rates were much higher across the gas/liquid interfaces of the three-phase separators (5.4-9.7 kg CH(4) m(-2) d(-1) and 23.0-35.8 g S m(-2) d(-1)) as compared with the quiescent settler surfaces (11.0-17.8 g CH(4) m(-2) d(-1) and 0.21 to 0.37 g S m(-2) d(-1)). The decrease of dissolved methane and dissolved hydrogen sulfide was very large in the discharging hydraulic structures very close to the reactor (>60 and >80%, respectively), largely due to the loss to the atmosphere, indicating that the concentration of these compounds will probably fall to values close to zero in the near downstream structures. The emission factors due to the release of dissolved methane in the discharge structure amounted to around 0.040 g CH(4) g COD(infl)(-1) and 0.060 g CH(4) g COD(rem)(-1), representing around 60% of the methane collected in the three-phase separator. PMID:22437020

  13. Hydrogen sulfide production and volatilization in a polymictic eutrophic saline lake, Salton Sea, California.

    PubMed

    Reese, Brandi Kiel; Anderson, Michael A; Amrhein, Christopher

    2008-11-15

    The Salton Sea is a large shallow saline lake located in southern California that is noted for high sulfate concentrations, substantial algal productivity, and very warm water column temperatures. These conditions are well-suited for sulfide production, and sulfide has been implicated in summer fish kills, although no studies have been conducted to specifically understand hydrogen sulfide production and volatilization there. Despite polymictic mixing patterns and relatively short accumulation periods, the amount of sulfide produced is comparable to meromictic lakes. Sulfide levels in the Salton Sea reached concentrations of 1.2 mmol L(-1) of total free sulfide in the hypolimnion and 5.6 mmol L(-1) in the sediment pore water. Strong winds in late July mixed H2S into the surface water, where it depleted the entire water column of dissolved oxygen and reached a concentration of 0.1 mmol L(-1). Sulfide concentrations exceeded the toxicity threshold of tilapia (Oreochromis mossambicus) and combined with strong anoxia throughout the water column, resulted in a massive fish kill. The mixing of sulfide into the surface waters also increased atmospheric H2S concentrations, reaching 1.0 micromol m(-3). The flux of sulfide from the sediment into the water column was estimated to range from 2-3 mmol m(-2) day(-1) during the winter and up to 8 mmol m(-2) day(-1) during the summer. Application of the two-layer model for volatilization indicates that up to 19 mmol m(-2) day(-1) volatilized from the surface during the mixing event. We estimate that as much as 3400 Mg year(-1) or approximately 26% of sulfide that diffused into the water column from the deepest sediments may have been volatilized to the atmosphere. PMID:18760446

  14. Fabrication and Characterization of Amorphous Cobalt-Doped Molybdenum Sulfide for Hydrogen Evolution Reaction.

    PubMed

    Lim, Dongwook; Hwang, Hyein; Kim, Taewoo; Shim, Sang Eun; Baeck, Sung-Hyeon

    2015-10-01

    In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conducted without using a precious metal catalyst. We synthesized an amorphous cobalt-doped molybdenum sulfide by electrodeposition using different cobalt loadings. The amorphous Co-MoSx produced was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The cobalt doping and sulfidation procedure resulted in the successful fabrication of a candidate catalyst for the catalytic hydrogen evolution in alkaline solution with high intrinsic activity. Cobalt incorporated amorphous MoSx exhibited 3 times higher HER activity than non-promoted MoSx. PMID:26726498

  15. Importance of Hydrogen Sulfide, Thiosulfate, and Methylmercaptan for Growth of Thiobacilli during Simulation of Concrete Corrosion.

    PubMed

    Sand, W

    1987-07-01

    Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli. PMID:16347391

  16. Importance of Hydrogen Sulfide, Thiosulfate, and Methylmercaptan for Growth of Thiobacilli during Simulation of Concrete Corrosion

    PubMed Central

    Sand, Wolfgang

    1987-01-01

    Biogenic sulfuric acid corrosion of concrete surfaces caused by thiobacilli was reproduced in simulation experiments. At 9 months after inoculation with thiobacilli, concrete blocks were severely corroded. The sulfur compounds hydrogen sulfide, thiosulfate, and methylmercaptan were tested for their corrosive action. With hydrogen sulfide, severe corrosion was noted. The flora was dominated by Thiobacillus thiooxidans. Thiosulfate led to medium corrosion and a dominance of Thiobacillus neapolitanus and Thiobacillus intermedius. Methylmercaptan resulted in negligible corrosion. A flora of heterotrophs and fungi grew on the blocks. This result implies that methylmercaptan cannot be degraded by thiobacilli. PMID:16347391

  17. The Response of Caenorhabditis elegans to Hydrogen Sulfide and Hydrogen Cyanide

    PubMed Central

    Budde, Mark W.; Roth, Mark B.

    2011-01-01

    Hydrogen sulfide (H2S), an endogenously produced small molecule, protects animals from various stresses. Recent studies demonstrate that animals exposed to H2S are long lived, resistant to hypoxia, and resistant to ischemiareperfusion injury. We performed a forward genetic screen to gain insights into the molecular mechanisms Caenorhabditis elegans uses to appropriately respond to H2S. At least two distinct pathways appear to be important for this response, including the H2S-oxidation pathway and the hydrogen cyanide (HCN)-assimilation pathway. The H2S-oxidation pathway requires two distinct enzymes important for the oxidation of H2S: the sulfide:quinone reductase sqrd-1 and the dioxygenase ethe-1. The HCN-assimilation pathway requires the cysteine synthase homologs cysl-1 and cysl-2. A low dose of either H2S or HCN can activate hypoxia-inducible factor 1 (HIF-1), which is required for C. elegans to respond to either gas. sqrd-1 and cysl-2 represent the entry points in the H2S-oxidation and HCN-assimilation pathways, respectively, and expression of both of these enzymes is highly induced by HIF-1 in response to both H2S and HCN. In addition to their role in appropriately responding to H2S and HCN, we found that cysl-1 and cysl-2 are both essential mediators of innate immunity against fast paralytic killing by Pseudomonas. Furthermore, in agreement with these data, we showed that growing worms in the presence of H2S is sufficient to confer resistance to Pseudomonas fast paralytic killing. Our results suggest the hypoxia-independent hif-1 response in C. elegans evolved to respond to the naturally occurring small molecules H2S and HCN. PMID:21840852

  18. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... analysis must be consistent with the EPA's risk management plan methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What hydrogen sulfide (H2S) information must... Development Operations Coordination Documents (docd) § 250.245 What hydrogen sulfide (H2S) information...

  19. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... analysis must be consistent with the EPA's risk management plan methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?...

  20. Bioconversion of High Concentrations of Hydrogen Sulfide to Elemental Sulfur in Airlift Bioreactor

    PubMed Central

    Abdel-Monaem Zytoon, Mohamed; Ahmad AlZahrani, Abdulraheem; Hamed Noweir, Madbuli; Ahmed El-Marakby, Fadia

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008?ppm and 31,215?ppm were applied and elimination capacities up to 113?g?H2S?m?3?h?1 were achieved in the airlift bioreactor under investigation at a pH range 6.58.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2?mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500?mg/L at pH values 8.08.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 88.5. PMID:25147857

  1. Characterizing ammonia and hydrogen sulfide emissions from a swine waste treatment lagoon in North Carolina

    NASA Astrophysics Data System (ADS)

    Blunden, Jessica; Aneja, Viney P.

    Emissions of atmospheric ammonia-nitrogen (NH 3-N, where NH 3-N=(14/17)NH 3) and hydrogen sulfide (H 2S) from a commercial anaerobic swine waste treatment lagoon (17,150 m 2 at normal liquid level) were measured over a 1-year period. Continuous simultaneous measurements were made at the lagoon using a dynamic flow-through chamber system for 1 week during four seasons, October-November 2004 (fall), February 2005 (winter), April 2005 (spring), and June 2005 (summer) in an effort to examine diurnal and seasonal variability, and the respective relationships of NH 3-N and H 2S emissions to lagoon physicochemical properties. Continuously measured lagoon physicochemical parameters include lagoon surface temperature and lagoon pH. Aqueous lagoon samples were collected daily and analyzed for total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), and total sulfide concentration. TKN, TAN, and sulfide concentrations ranged from 400-650, 360-590, and 0.1-13.0 mg L -1, respectively. For NH 3-N, the largest fluxes were observed during the summer (>4200 ?g N m -2 min -1). During the fall and spring, average NH 3-N fluxes were 1634505 and >2495 ?g N m -2 min -1, respectively. The lowest fluxes were observed during the winter where average flux values were 1290246 ?g N m -2 min -1. Fluxes for H 2S were negligible during the winter season. Average fluxes increased during the fall (0.30.1 ?g m -2 min -1) and spring (0.51.0 ?g m -2 min -1), and highest flux values were observed during the summer (5.33.2 ?g m -2 min -1). The seasonal NH 3-N and H 2S emission factors ranged from 10 to 40 kg N AU -1 yr -1 (1 AU=500 kg live animal weight) and 0 to 0.05 kg H 2S AU -1 yr -1, respectively. Generally, the lagoon emissions for H 2S were 3-4 orders of magnitude less than NH 3-N. The gas fluxes were related to various physicochemical parameters including the pH and near-surface temperature of the lagoon, and the aqueous concentration of the respective gas.

  2. Ionic liquid-modified metal sulfides/graphene oxide nanocomposites for photoelectric conversion

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Zhang, Y; Pei, Qi; Feng, Ting; Mao, Hui; Zhang, Wei; Wu, Shuyao; Liu, Daliang; Wang, Hongyu; Song, Xi-Ming

    2015-08-01

    Ionic liquid-modified metal sulfides/graphene oxide nanocomposites are prepared via a facile electrostatic adsorption. Ionic liquid (IL) is firstly used as surface modifier and structure-directing agent of metal sulfide (MS) crystallization process, obtaining ionic liquid modified-MS (IL-MS) nanoparticles with positive charges on surface. IL-MS/GO is obtained by electrostatic adherence between positively charged IL-MS and negatively charged graphene oxide (GO). The as-prepared sample shows enhanced photocurrent and highly efficient photocatalytic activity under visible light irradiation, indicating IL-MS/GO nanocomposites greatly promoted the separation of photogenerated electron-hole pairs.

  3. Reaction of Hydrogen Sulfide with Oxygen in the Presence ofSulfite

    SciTech Connect

    Weres, Oleh; Tsao, Leon

    1983-01-01

    Commonly, abatement of hydrogen sulfide emissions from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One Mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. The authors studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDT are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use.

  4. Reaction of hydrogen sulfide with oxygen in the presence of sulfite

    SciTech Connect

    Weres, O.; Tsao, L.

    1983-01-14

    Commonly, abatement of hydrogen sulfide emission from a geothermal powerplant requires that hydrogen sulfide dissolved in the cooling water be eliminated by chemical reaction. Oxidation by atmospheric oxygen is the preferred reaction, but requires a suitable catalyst. Nickel is the most potent and thereby cheapest catalyst for this purpose. One mg/L nickel in the cooling water would allow 99% removal of hydrogen sulfide to be attained. A major drawback of catalytic air oxidation is that colloidal sulfur is a major reaction product; this causes rapid sludge accumulation and deposition of sulfur scale. We studied the kinetics and product distribution of the reaction of hydrogen sulfide with oxygen, catalyzed by nickel. Adding sodium sulfite to the solution completely suppresses formation of colloidal sulfur by converting it to thiosulfate. The oxidation reaction is an autocatalytic, free radical chain reaction. A rate expression for this reaction and a detailed reaction mechanism were developed. Nickel catalyzes the chain initiation step, and polysulfidoradical ions propagate the chains. Several complexes of iron and cobalt were also studied. Iron citrate and iron N-hydroxyEDTA are the most effective iron based catalysts. Uncomplexed cobalt is as effective as nickel, but forms a precipitate of cobalt oxysulfide and is too expensive for practical use. 33 figures, 9 tables.

  5. Hydrogen sulfide and nonmethane hydrocarbon emissions from broiler houses in the Southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen sulfide (H2S) and nonmethane hydrocarbon (NMHC) emissions from two mechanically ventilated commercial broiler houses located in the Southeastern United States were continuously monitored over 12 flocks during the one-year period of 2006-2007 as a joint effort between Iowa State University a...

  6. Removal of ammonia and hydrogen sulfide using biochar produced from pyrolyzing animal manures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. The emission of these gases can be substantially reduced using adsorption filters filled with biochar produced from pyrolysis of livestock residuals such as c...

  7. Assessment of Hydrogen Sulfide Minimum Detection Limits of an Open Path Tunable Diode Laser

    EPA Science Inventory

    During June 2007, U.S. EPA conducted a feasibility study to determine whether the EPA OTM 10 measurement approach, also known as radial plume mapping (RPM), was feasible. A Boreal open-path tunable diode laser (OP-TDL) to collect path-integrated hydrogen sulfide measurements alon...

  8. 76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... required by 1 CFR 21.1, regarding the lifted stay of hydrogen sulfide reporting requirements. In FR Doc... a document on August 22, 1994 (59 FR 43048) imposing stays on the reporting requirements for... Register of October 17, 2011 (76 FR 64022) should have lifted the Administrative Stay of the...

  9. Genetically Anchored Fluorescent Probes for Subcellular Specific Imaging of Hydrogen Sulfide

    PubMed Central

    Jiang, Xiqian; Sizovs, Antons; Wang, Meng C.; Provost, Christopher R.; Huang, Jia

    2016-01-01

    Imaging hydrogen sulfide (H2S) at the subcellular resolution will greatly improve the understanding of functions of this signaling molecule. Taking advantage of the protein labeling technologies, we report a general strategy for the development of organelle specific H2S probes, which enables sub-cellular H2S imaging essentially in any organelles of interest. PMID:26806071

  10. Compensation effect and volcano curve in toluene hydrogenation catalyzed by transition metal sulfides.

    PubMed

    Guernalec, N; Geantet, C; Cseri, T; Vrinat, M; Toulhoat, H; Raybaud, P

    2010-09-28

    Within the framework of volcano curves, a kinetic study of toluene hydrogenation catalyzed by transition metal sulfides highlights the variation of the apparent kinetic parameters as a function of the ab initio sulfur-metal bond energy descriptor and sulfo-reductive reaction conditions. PMID:20424734

  11. Presumed Hydrogen Sulfide-Mediated Neurotoxicity Following Streptococcus Anginosus Group Meningitis

    PubMed Central

    Verma, Sumit; Landisch, Rachel; Quirk, Brendan; Schmainda, Kathleen; Prah, Melissa; Whelan, Harry T.; Willoughby, Rodney E.

    2012-01-01

    Hydrogen sulfide (H2S) is an environmental toxicant and gaseous neurotransmitter. It is produced enterically by sulfur-reducing bacteria and invasive pathogens including Streptococcus anginosus group, Salmonella and Citrobacter. We describe putative focal H2S neurotoxicity following S. constellatus meningitis, treated with adjunctive sodium nitrite and hyperbaric oxygen therapy. PMID:23014355

  12. Kinetics and mechanism of the reaction of hydrogen sulfide with diaquacobinamide in aqueous solution

    PubMed Central

    Salnikov, Denis S.; Makarov, Sergei V.; van Eldik, Rudi; Kucherenko, Polina N.; Boss, Gerry R.

    2014-01-01

    We conducted a detailed kinetic study of the reaction of the vitamin B12 analog diaquacobinamide ((H2O)2Cbi(III)) with hydrogen sulfide in water from pH 3 to 11. The reaction proceeds in three steps: (i) formation of three different complexes between cobinamide and hydrogen sulfide, viz. (HO−)(HS−)Cbi(III), (H2O)(HS−)Cbi(III), and (HS−)2Cbi(III); (ii) inner-sphere electron transfer (ISET) in the two complexes with one coordinated HS− to form the reduced cobinamide complex [(H)S]Cbi(II); and (iii) addition of a second molecule of hydrogen sulfide to the reduced cobinamide. ISET does not proceed in the (HS−)2Cbi(III) complex. The final products of the reaction between cobinamide and hydrogen sulfide were found to be independent of pH, with the main product being a complex of cobinamide(II) with the anion-radical SSH2−. PMID:25580081

  13. Effect of sewer headspace air-flow on hydrogen sulfide removal by corroding concrete surfaces.

    PubMed

    Nielsen, Asbjrn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2012-03-01

    Hydrogen sulfide adsorption and oxidation by corroding concrete surfaces at different air-flows were quantified using a pilot-scale sewer reactor. The setup was installed in an underground sewer research station with direct access to wastewater. Hydrogen sulfide gas was injected into the headspace of the sewer reactor once per hour in peak concentrations of approximately 500 ppmv. The investigated range of sewer air-flows was representative for natural ventilated sewer systems, and covered both laminar and turbulent conditions. The experiments demonstrated a significant effect of sewer air-flow on the kinetics of hydrogen sulfide removal from the sewer headspace. From the lowest to the highest air-flow investigated, the rate of adsorption and oxidation increased more than threefold. At all air-flows, the reaction kinetics followed a simple n-th order rate equation with a reaction order of 0.8. The effect of air-flow on hydrogen sulfide adsorption and oxidation kinetics was quantified by a simple empirical equation. PMID:22755494

  14. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR HYDROGEN SULFIDE (EXTERNAL REVIEW DRAFT)

    EPA Science Inventory

    Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals. Occupational exposure occurs primarily from its presence in petroleum, n...

  15. VERIFICATION OF AMBIENT MONITORING TECHNOLOGIES FOR AMMONIA AND HYDROGEN SULFIDE AT ANIMAL FEEDING OPERATIONS

    EPA Science Inventory

    The increasing concentration of livestock agriculture into animal feeding operations (AFOs) has raised concerns about the environmental and potential health impact of the emissions from AFOs into the atmosphere. Gaseous ammonia (NH3) and hydrogen sulfide (H2...

  16. Genetically anchored fluorescent probes for subcellular specific imaging of hydrogen sulfide.

    PubMed

    Chen, Jianwei; Zhao, Mingkun; Jiang, Xiqian; Sizovs, Antons; Wang, Meng C; Provost, Christopher R; Huang, Jia; Wang, Jin

    2016-02-01

    Imaging hydrogen sulfide (H2S) at the subcellular resolution will greatly improve the understanding of functions of this signaling molecule. Taking advantage of the protein labeling technologies, we report a general strategy for the development of organelle specific H2S probes, which enables sub-cellular H2S imaging essentially in any organelles of interest. PMID:26806071

  17. CHROMATOGRAPHIC SEPARATION AND IDENTIFICATION OF PRODUCTS FROM THE REACTION OF DIMETHYLARSINIC ACID WITH HYDROGEN SULFIDE

    EPA Science Inventory

    The reaction of dimethylarsinic acid (DMAV) with hydrogen sulfide (H2S) is of biological significance and may be implicated in the overall toxicity and carcinogenicity of arsenic. The course of the reaction in aqueous phase was monitored and an initial product, dimethylthioarsin...

  18. VERIFICATION OF AMBIENT MONITORING TECHNOLOGIES FOR AMMONIA AND HYDROGEN SULFIDE AT ANIMAL FEEDING OPERATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The performance of two hydrogen sulfide and seven ambient ammonia monitoring technologies was recently verified by the U.S. EPA ETV Program’s AMS Center. The nine technologies verified by the AMS Center could be used to enhance the scientific understanding of the environmental effects that emissions...

  19. Hydrogen sulfide corrosion in waste-water collection and treatment systems. Report to Congress

    SciTech Connect

    Not Available

    1991-09-01

    The report to Congress describes the corrosive effects of hydrogen sulfide in Wastewater Collection and Treatment Systems. The extent to which uniform imposition of Categorical pretreatment standards excerbates the corrosion problem and the range of available options to deal with such effects.

  20. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: HORIBA INSTRUMENTS,INC., APSA-360 AMBIENT HYDROGEN SULFIDE ANALYZER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this verification test was to evaluate the APSA-360s performance in measuring gaseous hydrogen sulfide (H2S) in ambient air at an animal feeding operation (AFO). The verification test was conducted between April 25 and June 3, 2005, at a swine finishing farm near Ames, Iowa; the AP...

  1. Precipitation of heavy metals from coal ash leachate using biogenic hydrogen sulfide generated from FGD gypsum.

    PubMed

    Jayaranjan, Madawala Liyanage Duminda; Annachhatre, Ajit P

    2013-01-01

    Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H(2)S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation. PMID:23168629

  2. Use of AERMOD to determine a hydrogen sulfide emission factor for swine operations by inverse modeling

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, Patrick T.; Altmaier, Ralph

    2011-09-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 μg m -2 s -1 was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10 -7 μg yr -1 m -2 kg -1 was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1 M kg), concentrations within 0.5 km from the CAFO exceeded 25 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

  3. Human Cystathionine-β-Synthase Phosphorylation on Serine227 Modulates Hydrogen Sulfide Production in Human Urothelium

    PubMed Central

    d’Emmanuele di Villa Bianca, Roberta; Donnarumm, Erminia; Russo, Annapina; Fusco, Ferdinando; Ianaro, Angela; Mirone, Vincenzo; Cirino, Giuseppe; Russo, Giulia; Sorrentino, Raffaella

    2015-01-01

    Urothelium, the epithelial lining the inner surface of human bladder, plays a key role in bladder physiology and pathology. It responds to chemical, mechanical and thermal stimuli by releasing several factors and mediators. Recently it has been shown that hydrogen sulfide contributes to human bladder homeostasis. Hydrogen sulfide is mainly produced in human bladder by the action of cystathionine-β-synthase. Here, we demonstrate that human cystathionine-β-synthase activity is regulated in a cGMP/PKG-dependent manner through phosphorylation at serine 227. Incubation of human urothelium or T24 cell line with 8-Bromo-cyclic-guanosine monophosphate (8-Br-cGMP) but not dibutyryl-cyclic-adenosine monophosphate (d-cAMP) causes an increase in hydrogen sulfide production. This result is congruous with the finding that PKG is robustly expressed but PKA only weakly present in human urothelium as well as in T24 cells. The cGMP/PKG-dependent phosphorylation elicited by 8-Br-cGMP is selectively reverted by KT5823, a specific PKG inhibitor. Moreover, the silencing of cystathionine-β-synthase in T24 cells leads to a marked decrease in hydrogen sulfide production either in basal condition or following 8-Br-cGMP challenge. In order to identify the phosphorylation site, recombinant mutant proteins of cystathionine-β-synthase in which Ser32, Ser227 or Ser525 was mutated in Ala were generated. The Ser227Ala mutant cystathionine-β-synthase shows a notable reduction in basal biosynthesis of hydrogen sulfide becoming unresponsive to the 8-Br-cGMP challenge. A specific antibody that recognizes the phosphorylated form of cystathionine-β-synthase has been produced and validated by using T24 cells and human urothelium. In conclusion, human cystathionine-β-synthase can be phosphorylated in a PKG-dependent manner at Ser227 leading to an increased catalytic activity. PMID:26368121

  4. Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling

    PubMed Central

    OShaughnessy, Patrick T.; Altmaier, Ralph

    2011-01-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 g/m2-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 10?7 g/yr-m2-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels. PMID:21804761

  5. The Role of Hydrogen Sulfide in Evolution and the Evolution of Hydrogen Sulfide in Metabolism and Signaling.

    PubMed

    Olson, Kenneth R; Straub, Karl D

    2016-01-01

    The chemical versatility of sulfur and its abundance in the prebiotic Earth as reduced sulfide (H2S) implicate this molecule in the origin of life 3.8 billion years ago and also as a major source of energy in the first seven-eighths of evolution. The tremendous increase in ambient oxygen ?600 million years ago brought an end to H2S as an energy source, and H2S-dependent animals either became extinct, retreated to isolated sulfide niches, or adapted. The first 3 billion years of molecular tinkering were not lost, however, and much of this biochemical armamentarium easily adapted to an oxic environment where it contributes to metabolism and signaling even in humans. This review examines the role of H2S in evolution and the evolution of H2S metabolism and signaling. PMID:26674552

  6. The microscopic structure of the hydrogen liquids

    NASA Astrophysics Data System (ADS)

    Zoppi, M.; Bafile, U.; Celli, M.; Cuello, G. J.; Formisano, F.; Guarini, E.; Magli, R.; Neumann, M.

    2003-01-01

    We have measured the microscopic structure of liquid para-hydrogen by means of a neutron diffraction experiment on the D4C liquids diffractometer at Institute Laue-Langevin (Grenoble, France). This is the first direct neutron diffraction measurement of the static structure factor of hydrogen. The present determination of the microscopic structure of hydrogen is consistent with previous experimental determinations carried out on liquid deuterium and with path integral Monte Carlo simulations. The comparison with recent x-ray determinations is also satisfactory.

  7. Performance of biotrickling filters for hydrogen sulfide removal under starvation and shock loads conditions*

    PubMed Central

    Zhang, Lan-he; Meng, Xiu-li; Wang, Ying; Liu, Li-dan

    2009-01-01

    In the industrial operation of biotrickling filters for hydrogen sulfide (H2S) removal, shock loads or starvation was common due to process variations or equipment malfunctions. In this study, effects of starvation and shock loads on the performance of biotrickling filters for H2S removal were investigated. Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation. Compared to biomass, viable bacteria numbers decreased significantly during the starvation, especially when airflow was maintained in the absence of spray liquid. During the subsequent re-acclimation, all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions. The results show that the re-acclimation time, in the case of biotrickling filters for H2S removal, is mainly controlled by viable H2S oxidizing bacteria numbers. On the other hand, the biotrickling filters can protect against shock loads in inlet fluctuating H2S concentration after resuming normal operation. When the biotrickling filters were supplied with H2S at an input of lower than 1700 mg/m3, their removal efficiencies were nearly 98% regardless of previous H2S input. PMID:19650198

  8. Hydrogen sulfide decomposition into hydrogen and sulfur by quinone cycles. Final report, Part 1, June 1989-August 1992

    SciTech Connect

    Plummer, M.A.; Cowley, S.W.

    1993-02-01

    The HYSULF process decomposes hydrogen sulfide using mild conditions. In the process, hydrogen sulfide is first reacted with a quinone in an organic solvent to produce sulfur and hydroquinone. After sulfur removal, hydroquinone is catalytically processed to recover hydrogen and recycle quinone-solvent. The produced sulfur is of excellent quality and easily recoverable from the solvent. The organic solvent should eliminate corrosion problems associated with commercial aqueous redox systems which produce only sulfur. Since no air oxidation is used, the sulfite-sulfate salt problems of aqueous systems will be avoided. The purpose of the GRI contract was to develop a better mechanistic understanding of process chemical reactions and economics. This was to result in (1) Increased quinone conversion and sulfur precipitation rates; (2) Determining the effect of carbon dioxide on first stage chemistry; (3) Eliminating the anthrone by-product produced in the dehydrogenation step. Essentially, all of the objectives of the project were completed.

  9. Hydrogen sulfide decomposition into hydrogen and sulfur by quinone cycles. Second annual report, June 1990-May 1991

    SciTech Connect

    Plummer, M.A.; Cowley, S.W.

    1991-05-01

    The HYSULF process decomposes hydrogen sulfide using mild conditions. In the process, hydrogen sulfide is first reacted with a quinone in an organic solvent to produce sulfur and hydroquinone. After sulfur removal, hydroquinone is catalytically processed to recover hydrogen and recycle quinone-solvent. The produced sulfur is of excellent quality and easily recoverable from the solvent. The organic solvent should eliminate corrosion problems associated with commercial aqueous redox systems which produce only sulfur. Since no air oxidation is used, the sulfite-sulfate salt problems of aqueous systems will be avoided. The purpose of the GRI contract is to develop a better mechanistic understanding of process chemical reactions and economics. This should result in (1) Increased quinone conversion and sulfur precipitation rates; (2) Determining the effect of carbon dioxide on first stage chemistry; (3) Eliminating the anthrone by-product produced in the dehydrogenation step.

  10. H25*HOH or H2O*HSH, which is more stable in the water-hydrogen sulfide complex?

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Bo; Tao, Fu-Ming; Pan, Yuh-Kang

    1994-12-01

    High-level ab initio calculations are carried out to study the relative stability of the two hydrogen bonded structures of water-hydrogen sulfide complex, one with water as the proton donor (A) and the other with hydrogen sulfide as the proton donor (B). The results show that structure A is considerably more stable than B at the correlated level, which is in contrast with previous results obtained from Hartree-Fock calculations.

  11. Autotrophic denitrification for combined hydrogen sulfide removal from biogas and post-denitrification.

    PubMed

    Kleerebezem, R; Mendez, R

    2002-01-01

    In this paper we describe an alternative flow-chart for full treatment of wastewaters rich in organic substrates, ammonia (or organic nitrogen), and sulfate, such as those generated in fish cannery industries. Biogas generated during anaerobic pretreatment of these wastewaters is rich in hydrogen sulfide that needs to be removed to enable application of the biogas. Nitrogen elimination is traditionally achieved by subsequent nitrification and denitrification of the effluent of the anaerobic reactor. Alternatively, the hydrogen sulfide in the biogas can be applied as an electron donor in an autotrophic post-denitrification step. In order to study whether sufficient hydrogen sulfide containing biogas for denitrification was produced in the anaerobic reactor, the biogas composition as a function of the anaerobic reactor-pH was estimated based on a typical wastewater composition and chemical equilibrium equations. It is demonstrated that typical sulfate and nitrogen concentrations in fish cannery wastewater are highly appropriate for application of autotrophic post-denitrification. A literature review furthermore suggested that the kinetic parameters for autotrophic denitrification by Thiobacillus denitrificans represent no bottleneck for its application. Initial experimental studies in fixed-film reactors were conducted with sodium sulfide and nitrate as an electron donor-acceptor couple. The results revealed that only moderate volumetric treatment capacities (< 1 g-NO3- N l(-1) day(-1)) could be achieved. Mass balances suggested that incomplete sulfide oxidation to elemental sulfur occurred, limiting biomass retention and the treatment capacity of the reactor. Future research should clarify the questions concerning product formation from sulfide oxidation. PMID:12188569

  12. Human sulfide:quinone oxidoreductase catalyzes the first step in hydrogen sulfide metabolism and produces a sulfane sulfur metabolite.

    PubMed

    Jackson, Michael R; Melideo, Scott L; Jorns, Marilyn Schuman

    2012-08-28

    Sulfide:quinone oxidoreductase (SQOR) is a membrane-bound enzyme that catalyzes the first step in the mitochondrial metabolism of H(2)S. Human SQOR is successfully expressed at low temperature in Escherichia coli by using an optimized synthetic gene and cold-adapted chaperonins. Recombinant SQOR contains noncovalently bound FAD and catalyzes the two-electron oxidation of H(2)S to S(0) (sulfane sulfur) using CoQ(1) as an electron acceptor. The prosthetic group is reduced upon anaerobic addition of H(2)S in a reaction that proceeds via a long-wavelength-absorbing intermediate (?(max) = 673 nm). Cyanide, sulfite, or sulfide can act as the sulfane sulfur acceptor in reactions that (i) exhibit pH optima at 8.5, 7.5, or 7.0, respectively, and (ii) produce thiocyanate, thiosulfate, or a putative sulfur analogue of hydrogen peroxide (H(2)S(2)), respectively. Importantly, thiosulfate is a known intermediate in the oxidation of H(2)S by intact animals and the major product formed in glutathione-depleted cells or mitochondria. Oxidation of H(2)S by SQOR with sulfite as the sulfane sulfur acceptor is rapid and highly efficient at physiological pH (k(cat)/K(m,H(2)S) = 2.9 10(7) M(-1) s(-1)). A similar efficiency is observed with cyanide, a clearly artificial acceptor, at pH 8.5, whereas a 100-fold lower value is seen with sulfide as the acceptor at pH 7.0. The latter reaction is unlikely to occur in healthy individuals but may become significant under certain pathological conditions. We propose that sulfite is the physiological acceptor of the sulfane sulfur and that the SQOR reaction is the predominant source of the thiosulfate produced during H(2)S oxidation by mammalian tissues. PMID:22852582

  13. Pad B Liquid Hydrogen Storage Tank

    NASA Technical Reports Server (NTRS)

    Hall, Felicia

    2007-01-01

    Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

  14. Hydrogen bonding in ionic liquids.

    PubMed

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-01

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (?BCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H ?* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak through to very strong H-bonds. PMID:25582457

  15. Method of removing hydrogen sulfide from gases utilizing a zinc oxide sorbent and regenerating the sorbent

    DOEpatents

    Jalan, Vinod M. (Concord, MA); Frost, David G. (Maynard, MA)

    1984-01-01

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500.degree. C. to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent.

  16. Direct Chlorination Process for geothermal power plant off-gas - hydrogen sulfide abatement

    SciTech Connect

    Sims, A.V.

    1983-06-01

    The Direct Chlorination Process removes hydrogen sulfide from geothermal off-gases by reacting hydrogen sulfide with chlorine in the gas phase. Hydrogen chloride and elemental sulfur are formed by this reaction. The Direct Chlorination Process has been successfully demonstrated by an on-site operation of a pilot plant at the 3 M We HPG-A geothermal power plant in the Puna District on the island of Hawaii. Over 99.5% hydrogen sulfide removal was achieved in a single reaction stage. Chlorine gas did not escape the pilot plant, even when 90% excess chlorine gas was used. A preliminary economic evaluation of the Direct Chlorination Process indicates that it is very competitive with the Stretford Process Compared to the Stretford Process, the Direct Chlorination process requires about one-third the initial capital investment and about one-fourth the net daily expenditure. Because of the higher cost of chemicals and the restricted markets in Hawaii, the economic viability of this process in Hawaii is questionable.

  17. Involvement of ERK in NMDA receptor-independent cortical neurotoxicity of hydrogen sulfide

    SciTech Connect

    Kurokawa, Yuko; Sekiguchi, Fumiko; Kubo, Satoko; Yamasaki, Yoshiko; Matsuda, Sachi; Okamoto, Yukari; Sekimoto, Teruki; Fukatsu, Anna; Nishikawa, Hiroyuki; Kume, Toshiaki; Fukushima, Nobuyuki; Akaike, Akinori; Kawabata, Atsufumi

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Hydrogen sulfide causes NMDA receptor-independent neurotoxicity in mouse fetal cortical neurons. Black-Right-Pointing-Pointer Activation of ERK mediates the toxicity of hydrogen sulfide. Black-Right-Pointing-Pointer Apoptotic mechanisms are involved in the hydrogen-induced cell death. -- Abstract: Hydrogen sulfide (H{sub 2}S), a gasotransmitter, exerts both neurotoxicity and neuroprotection, and targets multiple molecules including NMDA receptors, T-type calcium channels and NO synthase (NOS) that might affect neuronal viability. Here, we determined and characterized effects of NaHS, an H{sub 2}S donor, on cell viability in the primary cultures of mouse fetal cortical neurons. NaHS caused neuronal death, as assessed by LDH release and trypan blue staining, but did not significantly reduce the glutamate toxicity. The neurotoxicity of NaHS was resistant to inhibitors of NMDA receptors, T-type calcium channels and NOS, and was blocked by inhibitors of MEK, but not JNK, p38 MAP kinase, PKC and Src. NaHS caused prompt phosphorylation of ERK and upregulation of Bad, followed by translocation of Bax to mitochondria and release of mitochondrial cytochrome c, leading to the nuclear condensation/fragmentation. These effects of NaHS were suppressed by the MEK inhibitor. Our data suggest that the NMDA receptor-independent neurotoxicity of H{sub 2}S involves activation of the MEK/ERK pathway and some apoptotic mechanisms.

  18. Evaluation of a novel passive sampling technique for monitoring volcanogenic hydrogen sulfide.

    PubMed

    Horwell, Claire J; Allen, Andrew G; Mather, Tamsin A; Patterson, John E

    2004-07-01

    A novel, low-cost passive sampling procedure for monitoring of volcanogenic hydrogen sulfide is reported. The technique is based on absorption of H2S onto treated sections of photographic paper, which are housed in plastic film canisters during exposure. The H2S reacts with silver halide in the photographic paper, causing a colour-change reaction from white, through brown, to black, depending on concentration of atmospheric H2S. The sampler is sensitive to < 30 ppb to approximately 1000 ppb of H2S. Here we present results from a series of optimization and quantification experiments. An active sampling procedure for rapid H2S measurement is also reported, based on absorption of H2S onto Whatman No. 41 cellulose filters treated with silver nitrate, and was shown to be quantitative using a single filter at flow rates <1.0 L min(-1) for collection of <200 microg of sulfide (as H2S). Determination of sulfide collected on the substrates was performed using a rapid flow-injection technique based on the fluorescence quenching of fluorescein mercuric acetate (FMA) by sulfide. This was optimized at a FMA concentration of 8 mg L(-1), at which 100% quenching was obtained at a solution sulfide concentration of 3 mg L(-1). PMID:15237295

  19. Thermal properties of hydrogenated liquid natural rubber

    NASA Astrophysics Data System (ADS)

    Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

    2015-09-01

    Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

  20. DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, SIXTH LEVEL OF THE EXTERNAL TANK CHECK-OUT CELLS, HB-2, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  1. Efficient new process for the desulfurization of mixtures of air and hydrogen sulfide via a dielectric barrier discharge plasma

    NASA Astrophysics Data System (ADS)

    Dahle, S.

    2015-10-01

    The efficient removal of hydrogen sulfide, H2S, from streams of H2S in air via a dielectric barrier discharge (DBD) plasma has been investigated using a quadrupole mass spectrometer. A suitable plasma device with a reservoir for storing sorbent powder of various kinds within the plasma region was constructed. Plasma treatments of gas streams with high concentrations of hydrogen sulfide in air yielded a removal of more than 98% of the initial hydrogen sulfide and a deposition of sulfur at the surface of the dielectric, while small amounts of sulfur dioxide were generated. The presence of calcium carbonate within the plasma region of the DBD device resulted in the removal of over 99% of the initial hydrogen sulfide content and the removal of 98% of the initial sulfur dioxide impurities from the gas mixture.

  2. Hydrogen sulfide production in surface layers of sediments in the Atlantic Ocean (from radioisotope data)

    NASA Astrophysics Data System (ADS)

    Lein, A. Yu.; Ivanov, M. V.

    2015-11-01

    The report presents the results of 35S-radioisotope researches of sulfate reduction rates in Holocene sediments (0-20 cm) of the shelf and the continental slope at the eastern coasts of the Atlantic Ocean from 81 N to 25 S, including sediments in the most environmentally hazardous upwelling zones. Data from experiments on the rates of sulfate reduction were used in calculating the production of hydrogen sulfide. The rates of sulfate reduction are comparable at the polar shelf and the equatorial area of the influence of the Congo River (11.9 and 14.96 mg S/m2 day, respectively). It must be acknowledged that the production of microbial diagenetic hydrogen sulfide is first affected by the content and composition of organic matter in the sediments and secondly by the thermal conditions of the basin.

  3. Selective Catalytic Oxidation of Hydrogen Sulfide on Activated Carbons Impregnated with Sodium Hydroxide

    SciTech Connect

    Schwartz, Viviane; Baskova, Svetlana; Armstrong, Timothy R.

    2009-01-01

    Two activated carbons of different origin were impregnated with the solution of sodium hydroxide (NaOH) of various concentrations up to 10 wt %, and the effect of impregnation on the catalytic performance of the carbons was evaluated. The catalytic activity was analyzed in terms of the capacity of carbons for hydrogen sulfide (H2S) conversion and removal from hydrogen-rich fuel streams and the emission times of H2S and the products of its oxidation [e.g., sulfur dioxide (SO2) and carbonyl sulfide (COS)]. The results of impregnation showed a significant improvement in the catalytic activity of both carbons proportional to the amount of NaOH introduced. NaOH introduces hydroxyl groups (OH-) on the surface of the activated carbon that increase its surface reactivity and its interaction with sulfur-containing compounds.

  4. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOEpatents

    Siriwardane, Ranjani V. (Morgantown, WV)

    1997-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  5. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOEpatents

    Siriwardane, R.V.

    1999-02-02

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  6. Durable regenerable sorbent pellets for removal of hydrogen sulfide coal gas

    DOEpatents

    Siriwardane, Ranjani V. (Morgantown, WV)

    1999-01-01

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  7. Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

    DOEpatents

    Siriwardane, R.V.

    1997-12-30

    Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

  8. Production of hydrogen in non oxygen-evolving systems: co-produced hydrogen as a bonus in the photodegradation of organic pollutants and hydrogen sulfide

    SciTech Connect

    Sartoretti, C. Jorand; Ulmann, M.; Augustynski, J. ); Linkous, C.A. )

    2000-01-01

    This report was prepared as part of the documentation of Annex 10 (Photoproduction of Hydrogen) of the IEA Hydrogen Agreement. Subtask A of this Annex concerned photo-electrochemical hydrogen production, with an emphasis on direct water splitting. However, studies of non oxygen-evolving systems were also included in view of their interesting potential for combined hydrogen production and waste degradation. Annex 10 was operative from 1 March 1995 until 1 October 1998. One of the collaborative projects involved scientists from the Universities of Geneva and Bern, and the Federal Institute of Technology in Laussane, Switzerland. A device consisting of a photoelectrochemical cell (PEC) with a WO{sub 3} photoanode connected in series with a so-called Grazel cell (a dye sensitized liquid junction photovoltaic cell) was developed and studied in this project. Part of these studies concerned the combination of hydrogen production with degradation of organic pollutants, as described in Chapter 3 of this report. For completeness, a review of the state of the art of organic waste treatment is included in Chapter 2. Most of the work at the University of Geneva, under the supervision of Prof. J. Augustynski, was focused on the development and testing of efficient WO{sub 3} photoanodes for the photoelectrochemical degradation of organic waste solutions. Two types of WO{sub 3} anodes were developed: non transparent bulk photoanodes and non-particle-based transparent film photoanodes. Both types were tested for degradation and proved to be very efficient in dilute solutions. For instance, a solar-to-chemical energy conversion efficiency of 9% was obtained by operating the device in a 0.01M solution of methanol (as compared to about 4% obtained for direct water splitting with the same device). These organic compounds are oxidized to CO{sub 2} by the photocurrent produced by the photoanode. The advantages of this procedure over conventional electrolytic degradation are that much (an order of magnitude) less energy is required and that sunlight can be used directly. In the case of photoproduction of hydrogen, as compared to water splitting, feeding the anodic compartment of the PEC with an organic pollutant, instead of the usual supporting electrolyte, will bring about a substantial increase of the photocurrent at a given illumination. Thus, the replacement of the photo-oxidation of water by the photodegradation of organic waste will be accompanied by a gain in solar-to-chemical conversion efficiency and hence by a decrease in the cost of the photoproduced hydrogen. Taking into account the benefits and possible revenues obtainable by the waste degradation, this would seem to be a promising approach to the photoproduction of hydrogen. Hydrogen sulfide (H{sub 2}S) is another waste effluent requiring extensive treatment, especially in petroleum refineries. The so-called Claus process is normally used to convert the H{sub 2}S to elemental sulfur. A sulfur recovery process developed at the Florida Solar Energy Center is described briefly in Chapter 4 by Dr. C. Linkous as a typical example of the photoproduction of hydrogen in a non oxygen-evolving system. The encouraging results obtained in these investigations of photoelectrochemical hydrogen production combined with organic waste degradation, have prompted a decision to continue the work under the new IEA Hydrogen Agreement Annex 14, Photoelectrolytic Hydrogen Production.

  9. Hydrogen sulfide on Io - Evidence from telescopic and laboratory infrared spectra

    NASA Astrophysics Data System (ADS)

    Nash, D. B.; Howell, R. R.

    1989-04-01

    Evidence is reported for hydrogen sulfide on Io's surface. An infrared band at 3.915 (+ or - 0.015) micrometers in several ground-based spectra of Io can be accounted for by reflectance from H2S frost deposited on or cocondensed with sulfur dioxide frost. Temporal variation in the occurrence and intensity of the band suggests that condensed H2S on Io's surface is transient, implying a similar variation of H2S abundance in Io's atmosphere.

  10. Ammonia, hydrogen sulfide, carbon dioxide and particulate matter emissions from California high-rise layer houses

    NASA Astrophysics Data System (ADS)

    Lin, X.-J.; Cortus, E. L.; Zhang, R.; Jiang, S.; Heber, A. J.

    2012-01-01

    Ammonia and hydrogen sulfide are hazardous substances that are regulated by the U.S. Environmental Protection Agency through community right-to-know legislation (EPCRA, EPA, 2011). The emissions of ammonia and hydrogen sulfide from large commercial layer facilities are of concern to legislators and nearby neighbors. Particulate matter (PM 10 and PM 2.5) released from layer houses are two of seven criteria pollutants for which EPA has set National Ambient Air Quality Standards as required by the Clean Air Act. Therefore, it is important to quantify the baseline emissions of these pollutants. The emissions of ammonia, hydrogen sulfide, carbon dioxide and PM from two California high-rise layer houses were monitored for two years from October 2007 to October 2009. Each house had 32,500 caged laying hens. The monitoring site was setup in compliance with a U.S. EPA-approved quality assurance project plan. The results showed the average daily mean emission rates of ammonia, hydrogen sulfide and carbon dioxide were 0.95 0.67 (standard deviation) g d -1 bird -1, 1.27 0.78 mg d -1 bird -1 and 91.4 16.5 g d -1 bird -1, respectively. The average daily mean emission rates of PM 2.5, PM 10 and total suspended particulate (TSP) were 5.9 12.6, 33.4 27.4, and 78.0 42.7 mg d -1 bird -1, respectively. It was observed that ammonia emission rates in summer were lower than in winter because the high airflow stabilized the manure by drying it. The reductions due to lower moisture content were greater than the increases due to higher temperature. However, PM 10 emission rates in summer were higher than in winter because the drier conditions coupled with higher internal air velocities increased PM 10 release from feathers, feed and manure.

  11. Naturally occurring vapor-liquid-solid (VLS) Whisker growth of germanium sulfide

    USGS Publications Warehouse

    Finkelman, R.B.; Larson, R.R.; Dwornik, E.J.

    1974-01-01

    The first naturally occurring terrestrial example of vapor-liquid-solid (VLS) growth has been observed in condensates from gases released by burning coal in culm banks. Scanning electron microscopy, X-ray diffraction, and energy dispersive analysis indicate that the crystals consist of elongated rods (??? 100 ??m) of germanium sulfide capped by bulbs depleted in germanium. ?? 1974.

  12. Contribution of dissolved sulfates and sulfites in hydrogen sulfide emission from stagnant water bodies in Sri Lanka.

    PubMed

    Kularatne, K I A; Dissanayake, D P; Mahanama, K R R

    2003-08-01

    Accumulation of sulfur-containing compounds and their bacterial mediated reductions have led to the emission of pungent odors from stagnant water bodies. This study is focused on the contribution of inorganic sulfur compounds in the emission of hydrogen sulfide. The measured dissolved oxygen levels have demonstrated good negative correlations with the dissolved sulfide levels implying the oxygen deficiency is the key for the reduction of sulfate ion and sulfite ion to sulfide ion. Particularly, the dissolved molar fractions of sulfide from the total dissolved sulfur compounds (sulfates, sulfites and sulfides) have a very good correlation with the dissolved oxygen for the stagnant water bodies except the artificially aerated prawn farms. For the stagnant water bodies with significant correlations, linear regressions are reported for them to be utilized in estimating one component of the regression from the measurement of the other. The measured data were further utilized to estimate the levels of hydrogen sulfide gas. The pH of the water bodies has confined much of the dissolved sulfides in the form of bisulfide ion and they can be easily escaped to the atmosphere upon acidification due to industrial discharges and/or acidic precipitations. The estimated levels of hydrogen sulfide just above the water surface were plotted for the most polluted stagnant water body in Sri Lanka for the pH range of 5-10 and temperature range of 25-35 degrees C. PMID:12757791

  13. Multicomponent sulfides as narrow gap hydrogen evolution photocatalysts.

    PubMed

    Ikeda, Shigeru; Nakamura, Takayuki; Harada, Takashi; Matsumura, Michio

    2010-11-14

    A series of mixed crystals composed of Cu(2)ZnSnS(4), Ag(2)ZnSnS(4) and ZnS was prepared by co-precipitation of the corresponding metal ions in aqueous sodium sulfide followed by annealing in a sulfur atmosphere. Ideal solid solutions of Cu(2)ZnSnS(4) and Ag(2)ZnSnS(4) with a kesterite structure ((Cu(x)Ag(1-x))(2)ZnSnS(4) (0 ?x? 1)) were successfully obtained by this procedure, as confirmed by their X-ray diffraction (XRD) patterns and energy-diffuse X-ray (EDX) analyses. On the other hand, the solubility of ZnS in these kesterite compounds was found to be limited: the upper limit of the ratio of ZnS to (Cu(x)Ag(1-x))(2)ZnSnS(4) was less than 0.1, regardless of the Cu-Ag ratio in (Cu(x)Ag(1-x))(2)ZnSnS(4). Based on the results for dependence of their photoabsorption properties on atomic compositions, a plausible band structure is discussed. Evaluation of the photocatalytic activity for H(2) evolution of these mixed crystals from an aqueous solution containing S(2-) and SO(3)(2-) ions upon loading Ru catalysts under simulated solar radiation (AM 1.5) revealed that active compounds for this reaction should contain both dissolved ZnS and Ag components. The dissolved ZnS in (Cu(x)Ag(1-x))(2)ZnSnS(4) gave upward shifts of their conduction band edges. Moreover, the presence of Ag in the solid solution provided n-type conductivity, leading to efficient migration of photogenerated electrons to the surface to induce water reduction into H(2). PMID:20852813

  14. Application of biofiltration to the degradation of hydrogen sulfide in gas effluents.

    PubMed

    Elas, A; Barona, A; Ros, F J; Arreguy, A; Munguira, M; Peas, J; Sanz, J L

    2000-01-01

    A laboratory scale bioreactor has been designed and set up in order to degrade hydrogen sulfide from an air stream. The reactor is a vertical column of 7 litre capacity and 1 meter in height. It is divided into three modules and each module is filled with pellets of agricultural residues as packing bed material. The gas stream fed into the reactor through the upper inlet consists of a mixture of hydrogen sulfide and humidified air. The hydrogen sulfide content in the inlet gas stream was increased in stages until the degradation efficiency was below 90%. The parameters to be controlled in order to reach continuous and stable operation were temperature, moisture content and the percentage of the compound to be degraded at the inlet and outlet gas streams (removal or elimination efficiency). When the H2S mass loading rate was between 10 and 40 g m(-3) h(-1), the removal efficiency was greater than 90%. The support material had a good physical performance throughout operation time, which is evidence that this material is suitable for biofiltration purposes. PMID:11587447

  15. The study of an intermediate temperature solid state fuel cell utilizing hydrogen sulfide as the fuel

    NASA Astrophysics Data System (ADS)

    Peterson, David Ross

    A fuel cell using hydrogen sulfide as the fuel and consisting of a solid electrolyte, which conducts ions at intermediate temperatures (500-800sp°C), was studied. Utilization of this pollutant in this manner would produce clean electrical energy, as opposed to heat which is generated in conventional Hsb2S processing via the Claus process, and simultaneously convert a highly toxic gas into benign raw materials. The primary concern was to find a suitable electrolyte. This material must be stable to hydrogen sulfide and preferably be strictly a proton conductor since oxide conduction could lead to SOsb2 generation. The electrolytes examined include samaria-doped ceria, ytterbia-doped strontium cerate, samaria-doped barium cerate, lithium sulfate, and lithium sulfate-alumina composites. Fuel cell experimental run results acquired using these five electrolytes, with platinum for the electrodes, are discussed. The fabrication and characterization of the electrolyte membranes and powders are also addressed. The most success was obtained with samaria-doped ceria. High power densities (9.8 mW/cmsp2 at 654sp°C), low anode overpotentials, relatively high exchange current densities, and the apparent stability of this material to hydrogen sulfide all indicate the significant potential of this electrolyte in a Hsb2S fuel cell.

  16. Toward a selective, sensitive, fast-responsive, and biocompatible two-photon probe for hydrogen sulfide in live cells.

    PubMed

    Singha, Subhankar; Kim, Dokyoung; Moon, Hyunsoo; Wang, Taejun; Kim, Ki Hean; Shin, Youn Ho; Jung, Junyang; Seo, Eunseok; Lee, Sang-Joon; Ahn, Kyo Han

    2015-01-20

    Hydrogen sulfide has emerged as an exciting endogenous gasotransmitter in addition to nitric oxide and carbon dioxide. Noninvasive detection methods for hydrogen sulfide thus become indispensable tools for studying its diverse roles in biological systems. Accordingly, fluorescent probes for hydrogen sulfide have received great attention in recent years. A practically useful fluorescent probe for bioimaging of hydrogen sulfide should be selective, sensitive, fast-responsive, biocompatible, observable in the biological optical window, and capable of deep-tissue imaging. These sensing properties, however, are extremely difficult to achieve at the same time. Disclosed here is the two-photon fluorescent probe that meets all of these criteria. The probe belongs to a Michael acceptor system, which raised a serious selectivity issue over the competing biothiols such as cysteine and glutathione. We have addressed the selectivity issue by optimizing the electronic and steric interactions between biothiols and the probe, in addition to achieving very high sensitivity, fast-response, and biocompatibility. Also, the sensing mechanism suggested in the literature was revised. The probe thus enables us to image the endogenously produced hydrogen sulfide with negligible interference from other biothiols in live cells. The excellent sensing properties of the probe combined with its capability of bioimaging thus make it a practically useful tool for further studying biological roles of hydrogen sulfide. PMID:25495776

  17. Detrimental effects for colonocytes of an increased exposure to luminal hydrogen sulfide: The adaptive response.

    PubMed

    Beaumont, Martin; Andriamihaja, Mireille; Lan, Annaïg; Khodorova, Nadezda; Audebert, Marc; Blouin, Jean-Marc; Grauso, Marta; Lancha, Luciana; Benetti, Pierre-Henri; Benamouzig, Robert; Tomé, Daniel; Bouillaud, Frédéric; Davila, Anne-Marie; Blachier, François

    2016-04-01

    Protein fermentation by the gut microbiota releases in the large intestine lumen various amino-acid derived metabolites. Among them, hydrogen sulfide (H2S) in excess has been suspected to be detrimental for colonic epithelium energy metabolism and DNA integrity. The first objective of this study was to evaluate in rats the epithelial response to an increased exposure to H2S. Experiments from colonocyte incubation and intra-colonic instillation indicate that low millimolar concentrations of the sulfide donor NaHS reversibly inhibited colonocyte mitochondrial oxygen consumption and increased gene expression of hypoxia inducible factor 1α (Hif-1α) together with inflammation-related genes namely inducible nitric oxide synthase (iNos) and interleukin-6 (Il-6). Additionally, rat colonocyte H2S detoxification capacity was severely impaired in the presence of nitric oxide. Based on the γH2AX ICW technique, NaHS did not induce DNA damage in colonocytes. Since H2S is notably produced by the gut microbiota from sulfur containing amino acids, the second objective of the study was to investigate the effects of a high protein diet (HPD) on large intestine luminal sulfide content and on the expression of genes involved in H2S detoxification in colonocytes. We found that HPD markedly increased H2S content in the large intestine but the concomitant increase of the content mass maintained the luminal sulfide concentration. HPD also provoked an increase of sulfide quinone reductase (Sqr) gene expression in colonocytes, indicating an adaptive response to increased H2S bacterial production. In conclusion, low millimolar NaHS concentration severely affects colonocyte respiration in association with increased expression of genes associated with intestinal inflammation. Although HPD increases the sulfide content of the large intestine, the colonic adaptive responses to this modification limit the epithelial exposure to this deleterious bacterial metabolite. PMID:26849947

  18. Giant Hydrogen Sulfide Plume in the Oxygen Minimum Zone off Peru Supports Chemolithoautotrophy

    PubMed Central

    Großkopf, Tobias; Kalvelage, Tim; Löscher, Carolin R.; Paulmier, Aurélien; Contreras, Sergio; Siegel, Herbert; Holtappels, Moritz; Rosenstiel, Philip; Schilhabel, Markus B.; Graco, Michelle; Schmitz, Ruth A.; Kuypers, Marcel M. M.; LaRoche, Julie

    2013-01-01

    In Eastern Boundary Upwelling Systems nutrient-rich waters are transported to the ocean surface, fuelling high photoautotrophic primary production. Subsequent heterotrophic decomposition of the produced biomass increases the oxygen-depletion at intermediate water depths, which can result in the formation of oxygen minimum zones (OMZ). OMZs can sporadically accumulate hydrogen sulfide (H2S), which is toxic to most multicellular organisms and has been implicated in massive fish kills. During a cruise to the OMZ off Peru in January 2009 we found a sulfidic plume in continental shelf waters, covering an area >5500 km2, which contained ∼2.2×104 tons of H2S. This was the first time that H2S was measured in the Peruvian OMZ and with ∼440 km3 the largest plume ever reported for oceanic waters. We assessed the phylogenetic and functional diversity of the inhabiting microbial community by high-throughput sequencing of DNA and RNA, while its metabolic activity was determined with rate measurements of carbon fixation and nitrogen transformation processes. The waters were dominated by several distinct γ-, δ- and ε-proteobacterial taxa associated with either sulfur oxidation or sulfate reduction. Our results suggest that these chemolithoautotrophic bacteria utilized several oxidants (oxygen, nitrate, nitrite, nitric oxide and nitrous oxide) to detoxify the sulfidic waters well below the oxic surface. The chemolithoautotrophic activity at our sampling site led to high rates of dark carbon fixation. Assuming that these chemolithoautotrophic rates were maintained throughout the sulfidic waters, they could be representing as much as ∼30% of the photoautotrophic carbon fixation. Postulated changes such as eutrophication and global warming, which lead to an expansion and intensification of OMZs, might also increase the frequency of sulfidic waters. We suggest that the chemolithoautotrophically fixed carbon may be involved in a negative feedback loop that could fuel further sulfate reduction and potentially stabilize the sulfidic OMZ waters. PMID:23990875

  19. Development of Automotive Liquid Hydrogen Storage Systems

    NASA Astrophysics Data System (ADS)

    Krainz, G.; Bartlok, G.; Bodner, P.; Casapicola, P.; Doeller, Ch.; Hofmeister, F.; Neubacher, E.; Zieger, A.

    2004-06-01

    Liquid hydrogen (LH2) takes up less storage volume than gas but requires cryogenic vessels. State-of-the-art applications for passenger vehicles consist of double-wall cylindrical tanks that hold a hydrogen storage mass of up to 10 kg. The preferred shell material of the tanks is stainless steel, since it is very resistant against hydrogen brittleness and shows negligible hydrogen permeation. Therefore, the weight of the whole tank system including valves and heat exchanger is more than 100 kg. The space between the inner and outer vessel is mainly used for thermal super-insulation purposes. Several layers of insulation foils and high vacuums of 10-3 Pa reduce the heat entry. The support structures, which keep the inner tank in position to the outer tank, are made of materials with low thermal conductivity, e.g. glass or carbon fiber reinforced plastics. The remaining heat in-leak leads to a boil-off rate of 1 to 3 percent per day. Active cooling systems to increase the stand-by time before evaporation losses occur are being studied. Currently, the production of several liquid hydrogen tanks that fulfill the draft of regulations of the European Integrated Hydrogen Project (EIHP) is being prepared. New concepts of lightweight liquid hydrogen storage tanks will be investigated.

  20. Modeling leaks from liquid hydrogen storage systems.

    SciTech Connect

    Winters, William Stanley, Jr.

    2009-01-01

    This report documents a series of models for describing intended and unintended discharges from liquid hydrogen storage systems. Typically these systems store hydrogen in the saturated state at approximately five to ten atmospheres. Some of models discussed here are equilibrium-based models that make use of the NIST thermodynamic models to specify the states of multiphase hydrogen and air-hydrogen mixtures. Two types of discharges are considered: slow leaks where hydrogen enters the ambient at atmospheric pressure and fast leaks where the hydrogen flow is usually choked and expands into the ambient through an underexpanded jet. In order to avoid the complexities of supersonic flow, a single Mach disk model is proposed for fast leaks that are choked. The velocity and state of hydrogen downstream of the Mach disk leads to a more tractable subsonic boundary condition. However, the hydrogen temperature exiting all leaks (fast or slow, from saturated liquid or saturated vapor) is approximately 20.4 K. At these temperatures, any entrained air would likely condense or even freeze leading to an air-hydrogen mixture that cannot be characterized by the REFPROP subroutines. For this reason a plug flow entrainment model is proposed to treat a short zone of initial entrainment and heating. The model predicts the quantity of entrained air required to bring the air-hydrogen mixture to a temperature of approximately 65 K at one atmosphere. At this temperature the mixture can be treated as a mixture of ideal gases and is much more amenable to modeling with Gaussian entrainment models and CFD codes. A Gaussian entrainment model is formulated to predict the trajectory and properties of a cold hydrogen jet leaking into ambient air. The model shows that similarity between two jets depends on the densimetric Froude number, density ratio and initial hydrogen concentration.

  1. Fluorescence signaling of hydrogen sulfide in broad pH range using a copper complex based on BINOL-benzimidazole ligands.

    PubMed

    Sun, Mingtai; Yu, Huan; Li, Huihui; Xu, Hongda; Huang, Dejian; Wang, Suhua

    2015-04-20

    A weakly fluorescent complex derived from a binaphthol-benzimidazole ligand was designed and synthesized for hydrogen sulfide at different pH conditions. It was demonstrated that the probe showed the same reactivity to various hydrogen sulfide species in a broad range of pH values to generate highly fluorescent product through a displacement reaction mechanism, whereas the product's fluorescence spectrum exhibited a hypsochromic shift of ?73 nm (2393 cm(-1)) as pH increased from neutral to basic, which can be used for distinguishing the various species of hydrogen sulfide. This turn-on fluorescence probe was highly selective and sensitive to hydrogen sulfide with a detection limit of 0.11 ?M. It was then applied for evaluating the total content of sulfide (including hydrogen sulfide, hydrosulfide, and sulfide) as well as for the visual detection of gaseous H2S in air using a simple test paper strip. PMID:25839192

  2. Liquid Hydrogen Target Experience at SLAC

    SciTech Connect

    Weisend, J.G.; Boyce, R.; Candia, A.; Kaminskas, W.; Mark, J.; Racine, M.; St. Lorant, S.; Weber, T.; Arnold, R.; Bosted, P.; Carr, R.; Gao, J.; Jones, C.E.; McKeown, R.; /Caltech

    2005-08-29

    Liquid hydrogen targets have played a vital role in the physics program at SLAC for the past 40 years. These targets have ranged from small ''beer can'' targets to the 1.5 m long E158 target that was capable of absorbing up to 800 W without any significant density changes. Successful use of these targets has required the development of thin wall designs, liquid hydrogen pumps, remote positioning and alignment systems, safety systems, control and data acquisition systems, cryogenic cooling circuits and heat exchangers. Detailed operating procedures have been created to ensure safety and operational reliability. This paper surveys the evolution of liquid hydrogen targets at SLAC and discusses advances in several of the enabling technologies that made these targets possible.

  3. Electrochemical separation and concentration of hydrogen sulfide from gas mixtures

    DOEpatents

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  4. Plasma-chemical treatment of hydrogen sulfide in natural gas processing. Final report, May 1991--December 1992

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.

    1993-05-01

    A new process for the treatment of hydrogen sulfide waste that uses microwave plasma-chemical technology has been under development in Russia and the United States. Whereas the present waste-treatment technology, at best, only recovers sulfur, this novel process recovers both hydrogen and sulfur by dissociating hydrogen sulfide in a plasma by means of a microwave or radio-frequency reactor. A research project has been undertaken to determine the suitability of the plasma process in natural gas processing applications. The experiments tested acid-gas compositions with 30--65% carbon dioxide, 0--7% water, and 0--0.2% of a standard mixture of pipeline gas. The balance gas in all cases was hydrogen sulfide. The reactor pressure for the experiments was 50 torr, and the microwave power was 1.0 kW. Conversions of hydrogen sulfide ranged from 80 to 100%, while 35--50% of the carbon dioxide was converted to carbon monoxide. This conversion of carbon dioxide resulted in a loss of hydrogen production and an energy loss from a hydrogen sulfide waste-treatment perspective. Tests of a direct natural gas treatment concept showed that hydrocarbon losses were unacceptably high; consequently, the concept would not be economically viable.

  5. Hydrogen Sulfide (H2S) Releasing Agents: Chemistry and Biological Applications

    PubMed Central

    Zhao, Yu; Biggs, Tyler D.

    2014-01-01

    Hydrogen sulfide (H2S) is a newly recognized signaling molecule with very potent cytoprotective actions. The fields of H2S physiology and pharmacology have been rapidly growing in recent years, but a number of fundamental issues must be addressed to advance our understanding of the biology and clinical potential of H2S in the future. Hydrogen sulfide releasing agents (also known as H2S donors) have been widely used in the field. These compounds are not only useful research tools, but also potential therapeutic agents. It is therefore important to study the chemistry and pharmacology of exogenous H2S and to be aware of the limitations associated with the choice of donors used to generate H2S in vitro and in vivo. In this review we summarized the developments and limitations of current available donors including H2S gas, sulfide salts, garlic-derived sulfur compounds, Lawessons reagent/analogs, 1,2-dithiole-3-thiones, thiol-activated donors, photo-caged donors, and thioamino acids. Some biological applications of these donors were also discussed. PMID:25019301

  6. Crash test of a liquid hydrogen automobile

    NASA Technical Reports Server (NTRS)

    Finegold, J. G.; Van Vorst, W. D.

    1976-01-01

    Details of the conversion of a U.S. Postal Service mail truck to hydrogen-fueled operation are given. Specific reference is made to design safety considerations. A traffic accident is described that caused the mail truck (mounted on a trailer) to turn on its side at approximately 20 mph and to finally slide to a stop and turn upside down. No one was injured, and there was essentially no damage to the liquid hydrogen fuel system. The mail truck was driven away from the scene of the accident. Suggestions to insure the safety of hydrogen-fueled experimental vehicles are made.

  7. Liquid hydrogen in protonic chabazite.

    PubMed

    Zecchina, Adriano; Bordiga, Silvia; Vitillo, Jenny G; Ricchiardi, Gabriele; Lamberti, Carlo; Spoto, Giuseppe; Bjrgen, Morten; Lillerud, Karl Petter

    2005-05-01

    Due to its fully reversible nature, H(2) storage by molecular adsorption could represent an advantage with respect to dissociative processes, where kinetic effects during the charging and discharging processes are present. A drawback of this strategy is represented by the extremely weak interactions that require low temperature and high pressure. High surface area materials hosting polarizing sites can represent a viable way toward more favorable working conditions. Of these, in this contribution, we have studied hydrogen adsorption in a series of zeolites using volumetric techniques and infrared spectroscopy at 15 K. We have found that in H-SSZ-13 zeolite the cooperative role played by high surface area, internal wall topology, and presence of high binding energy sites (protons) allows hydrogen to densify inside the nanopores at favorable temperature and pressure conditions. PMID:15853343

  8. Mechanism analysis of improved DLC films friction behaviors with liquid sulfidation treatment

    NASA Astrophysics Data System (ADS)

    Zeng, Qunfeng; Yu, Fei; Dong, Guangneng; Mao, Junhong

    2012-10-01

    Diamond like carbon (DLC) films were treated by liquid sulfidation to improve their friction behaviors. Friction behaviors of DLC films were experimentally evaluated in ambient air under dry friction using GCr15 steel ball sliding over DLC-coated steel flat in a ball-on-disk tribometer system. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were applied to identify the chemical composition and structure of DLC films. It was found that the content of sp2 carbon bond increased and G peak shifted to high wave number after sulfidation treatment. The measurement results showed that sulfur atoms were chemically bonded and the graphitization occurred in the treated DLC films. It was indicated that the treated DLC films exhibited much better friction behaviors than the untreated films, especially for DLC films deposited with high nitrogen ratio. In this paper, we proposed the possible sulfidation mechanism of sulfurized DLC films. Sulfidation mechanism is postulated that thiourea reacted with oxygen to form sulfur-containing organic compounds which included CSSC, CSOH and (NH2)NHdbnd CSO2H and surface diffusion during sulfidation treatment. The anti-friction behaviors of the treated DLC films can be attributed to the production of the compounds containing sulfur on the DLC film surface, the reduce of oxygen content and the presence of graphitization of DLC films.

  9. Molybdate and tungstate doped porous carbons as hydrogen peroxide activation catalysts for sulfide oxidations

    SciTech Connect

    Drago, R.S.; Burns, D.S.

    1997-03-01

    Molybdenum and tungsten compounds activate hydrogen peroxide in homogeneous solution to oxidize a variety of substrates including organic sulfides. MoO{sub 4}{sup 2-} is also a remarkable nucleophile with a second-order rate constant 35 times that of phosphate for the hydrolysis of p-nitro-phenylacetate in spite of phosphate having a 1000-fold larger basicity. This research demonstrates that absorbent carbons, pore filled with molybdate and tungstate ions, are very effective catalysts for the oxidation of sulfides with 30% aqueous H{sub 2}O{sub 2}. The novel feature of these catalysts is that they carry out oxidations under basic conditions where G-agents would also undergo catalyzed hydrolysis.

  10. Redox biology of hydrogen sulfide: Implications for physiology, pathophysiology, and pharmacology?

    PubMed Central

    Stein, Asaf; Bailey, Shannon M.

    2013-01-01

    Hydrogen sulfide (H2S) has emerged as a critical mediator of multiple physiological processes in mammalian systems. The pathways involved in the production, consumption, and mechanism of action of H2S appear to be sensitive to alterations in the cellular redox state and O2 tension. Indeed, the catabolism of H2S through a putative oxidation pathway, the sulfide quinone oxido-reductase system, is highly dependent on O2 tension. Dysregulation of H2S homeostasis has also been implicated in numerous pathological conditions and diseases. In this review, the chemistry and the main physiological actions of H2S are presented. Some examples highlighting the cytoprotective actions of H2S within the context of cardiovascular disease are also reported. Elucidation of the redox biology of H2S will enable the development of new pharmacological agents based on this intriguing new redox cellular signal. PMID:23795345

  11. Hydrogen Sulfide Induced Carbon Dioxide Activation by Metal-Free Dual Catalysis.

    PubMed

    Kumar, Manoj; Francisco, Joseph S

    2016-03-18

    The role of metal free dual catalysis in the hydrogen sulfide (H2 S)-induced activation of carbon dioxide (CO2 ) and subsequent decomposition of resulting monothiolcarbonic acid in the gas phase has been explored. The results suggest that substituted amines and monocarboxylic type organic or inorganic acids via dual activation mechanisms promote both activation and decomposition reactions, implying that the judicious selection of a dual catalyst is crucial to the efficient C-S bond formation via CO2 activation. Considering that our results also suggest a new mechanism for the formation of carbonyl sulfide from CO2 and H2 S, these new insights may help in better understanding the coupling between the carbon and sulfur cycles in the atmospheres of Earth and Venus. PMID:26781129

  12. High Efficient Cryocooler for Liquid Hydrogen System

    NASA Astrophysics Data System (ADS)

    Nakagome, H.

    2006-04-01

    Conversion into Hydrogen Energy Society is advanced focusing on the application to a fuel cell electric vehicle. As volume and weight density of liquid hydrogen are large, it is the method which was most excellent as the storage method of hydrogen. However, in order to store liquid hydrogen stably over a long period of time, decreasing the loss of energy, development of an efficient small cryocooler becomes important. This paper reports the research about improvement in the refrigeration efficiency of a two-stage GM cryocooler. In order that the GM cryocooler may operate by the Simon expansion, it carries out asymptotic of the COP of the GM cryocooler to the Carnot COP as a compression ratio is lowered. When experimented based on this view, it was checked that refrigeration efficiency rises with reduction in a compression ratio. Furthermore, if the compression ratio is lowered, refrigeration efficiency will fall rapidly. The peak value of the refrigeration efficiency in 20K level attained 28%Carnot. It was verified by optimization of the compression ratio of the GM cryocooler that refrigeration efficiency can be improved significantly. Therefore, sharp reduction of the energy consumption of a liquid hydrogen system will be attained by applying the result of this research.

  13. Small, high-pressure liquid hydrogen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.; Sutton, R.

    1977-01-01

    A high pressure, liquid hydrogen turbopump was designed, fabricated, and tested to a maximum speed of 9739 rad/s and a maximum pump discharge pressure of 2861 N/sq. cm. The approaches used in the analysis and design of the turbopump are described, and fabrication methods are discussed. Data obtained from gas generator tests, turbine performance calibration, and turbopump testing are presented.

  14. Liquid Hydrogen Consumption During Space Shuttle Program

    NASA Technical Reports Server (NTRS)

    Partridge, Jonathan K.

    2011-01-01

    This slide presentation reviews the issue of liquid hydrogen consumption and the points of its loss in prior to the shuttle launch. It traces the movement of the fuel from the purchase to the on-board quantity and the loss that results in 54.6 of the purchased quantity being on board the Shuttle.

  15. Critical fields of liquid superconducting metallic hydrogen

    NASA Technical Reports Server (NTRS)

    Jaffe, J.; Ashcroft, N. W.

    1983-01-01

    Liquid metallic hydrogen, in a fully dissociated state, is predicted at certain densities to pass from dirty to clean and from type II to type I superconducting behavior as temperature is lowered. Previously announced in STAR as N82-29374

  16. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes.

    PubMed

    Sun, Mei; Sun, Wenjie; Barlaz, Morton A

    2016-05-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H2S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H2S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H2S produced by different types of sulfur-containing wastes in a relatively fast (30days) and inexpensive (125mL serum bottles) batch assay. This study confirmed the toxic effect of H2S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H2S by base adsorption was effective for mitigating inhibition. H2S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8mLH2S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H2S yield. A 60day incubation in selected samples resulted in 39-86% additional sulfide production. H2S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H2S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the microbial sulfide production potential of sulfur-containing wastes. PMID:26874757

  17. Hydrogen evolution using palladium sulfide (PdS) nanocorals as photoanodes in aqueous solution.

    PubMed

    Barawi, M; Ferrer, I J; Ares, J R; Snchez, C

    2014-11-26

    Palladium sulfide (PdS) nanostructures are proposed to be used as photoanodes in photoelectrochemical cells (PECs) for hydrogen evolution due to their adequate transport and optical properties shown in previous works. Here, a complete morphological and electrochemical characterization of PdS films has been performed by different techniques. PdS flatband potential (Vfb=-0.650.05 V vs NHE) was determined by electrochemical impedance spectroscopy measurements in aqueous Na2SO3 electrolyte, providing a description of the energy levels scheme at the electrolyte-semiconductor interface. This energy levels scheme confirms PdS as a compound able to photogenerate hydrogen in a PEC. At last, photogenerated hydrogen rates are measured continuously by mass spectrometry as a function of the external bias potential under illumination, reaching values up to 4.4 ?molH2/h at 0.3 V vs Ag/AgCl. PMID:25340641

  18. Liquid Hydrogen Sensor Considerations for Space Exploration

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.

    2006-01-01

    The on-orbit management of liquid hydrogen planned for the return to the moon will introduce new considerations not encountered in previous missions. This paper identifies critical liquid hydrogen sensing needs from the perspective of reliable on-orbit cryogenic fluid management, and contrasts the fundamental differences in fluid and thermodynamic behavior for ground-based versus on-orbit conditions. Opportunities for advanced sensor development and implementation are explored in the context of critical Exploration Architecture operations such as on-orbit storage, docking, and trans-lunar injection burn. Key sensing needs relative to these operations are also examined, including: liquid/vapor detection, thermodynamic condition monitoring, mass gauging, and leak detection. Finally, operational aspects of an integrated system health management approach are discussed to highlight the potential impact on mission success.

  19. EXTRACTION AND QUANTITATIVE ANALYSIS OF ELEMENTAL SULFUR FROM SULFIDE MINERAL SURFACES BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY. (R826189)

    EPA Science Inventory

    A simple method for the quantitative determination of elemental sulfur on oxidized sulfide minerals is described. Extraction of elemental sulfur in perchloroethylene and subsequent analysis with high-performance liquid chromatography were used to ascertain the total elemental ...

  20. Spectroscopic investigations into the binding of hydrogen sulfide to synthetic picket-fence porphyrins.

    PubMed

    Hartle, Matthew D; Prell, James S; Pluth, Michael D

    2016-03-21

    The reversible binding of hydrogen sulfide (H2S) to hemeprotein sites has been attributed to several factors, likely working in concert, including the protected binding pocket environment, proximal hydrogen bond interactions, and iron ligation environment. To investigate the importance of a sterically-constrained, protected environment on sulfide reactivity with heme centers, we report here the reactivity of H2S and HS(-) with the picket-fence porphyrin system. Our results indicate that the picket-fence porphyrin does not bind H2S in the ferric or ferrous state. By contrast, reaction of the ferric scaffold with HS(-) results in reduction to the ferrous species, followed by ligation of one equivalent of HS(-), as evidenced by UV-vis, NMR spectroscopy and mass spectrometry studies. Measurement of the HS(-) binding affinities in the picket-fence or tetraphenyl porphyrin systems revealed identical binding. Taken together, these results suggest that the protected, sterically-constrained binding pocket alone is not the primary contributor for stabilization of ferric H2S/HS(-) species in model systems, but that other interactions, such as hydrogen bonding, must play a critical role in facilitation of reversible interactions in ferric hemes. PMID:26869340

  1. Removal of hydrogen sulfide using crushed oyster shell from pore water to remediate organically enriched coastal marine sediments.

    PubMed

    Asaoka, Satoshi; Yamamoto, Tamiji; Kondo, Shunsuke; Hayakawa, Shinjiro

    2009-09-01

    Hydrogen sulfide is highly toxic and fatal to benthic organisms as well as causing depletion of dissolved oxygen and generating blue tide in eutrophic coastal seas. The purposes of this study are to reveal adsorption characteristics of hydrogen sulfide onto crushed oyster shell, and to evaluate removal efficiency of hydrogen sulfide from pore water in organically enriched sediments using container experiment in order to develop a coastal sediment amendment. The crushed oyster shell was mainly composed of CaCO(3) with calcite and CaO crystal phase. The batch experiment showed removal kinetics of hydrogen sulfide can be expressed as the first order equation and Langmuir plot fitted well in describing the adsorption behavior with the adsorption maximum at 12 mg-S g(-1). The container experiments suggested the oyster shell adsorbs hydrogen sulfide in pore water effectively and reduces oxygen consumption in the overlying water. Furthermore, oxidation-reduction potential of the sediment was higher with addition of crushed oyster shell than the control without oyster shell. Thus, it is concluded that crushed oyster shell can be an effective amendment to remediate organically enriched sediments in eutrophic coastal seas. PMID:19394819

  2. Effect of inoculum and sulfide type on simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry and microbial mechanism.

    PubMed

    Wang, Lan; Wei, Benping; Chen, Ziai; Deng, Liangwei; Song, Li; Wang, Shuang; Zheng, Dan; Liu, Yi; Pu, Xiaodong; Zhang, Yunhong

    2015-12-01

    Four reactors were initiated to study the effect of inoculum and sulfide type on the simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry (Ssu-Nir) process. Anaerobic sludge, aerobic sludge, and water were used as inocula, and Na2S and biogas were used as a sulfide substrate, respectively. Additionally, 454 pyrosequencing of the 16S rRNA gene was used to explore the bacterial diversity. The results showed that sulfur-oxidizing bacteria (Thiobacillus, 42.2-84.4%) were dominant in Ssu-Nir process and led to the excellent performance. Aerobic sludge was more suitable for inoculation of the Ssu-Nir process because it is better for rapidly enriching dominant sulfur-oxidizing bacteria (Thiobacillus, 54.4%), denitrifying sulfur-oxidizing bacteria (40.0%) and denitrifiers (23.9%). Lower S(2-) removal efficiency (72.6%) and NO3 (-) removal efficiency (<90%) of the Ssu-Nir process were obtained using biogas as a sulfide substrate than when Na2S was used. For the Ssu-Nir process with biogas as the sulfide substrate, limiting H2S absorption caused a high relative abundance of sulfur-oxidizing bacteria, Thiobacillus (84.8%) and Thiobacillus sayanicus (39.6%), which in turn led to low relative abundance of denitrifiers (1.6%) and denitrifying sulfur-oxidizing bacteria (24.4%), low NO3 (-) removal efficiency, and eventually poor performance. PMID:26286512

  3. Passivity of corrosion-resistant alloys in environments containing chloride and hydrogen sulfide

    SciTech Connect

    Denpo, K.; Ogawa, H.

    1997-09-01

    Passivity of corrosion-resistance alloys (CRA) in chloride (Cl{sup {minus}}) + hydrogen sulfide (H{sub 2}S) environments was investigated electrochemically to clarify the role of alloying elements. Pitting potential (V{prime}c) was correlated with alloying elements of Ni, Cr, and Mo. Ni was shown ineffective in improving pitting resistance in Cl{sup {minus}} environments. Passivity in Cl{sup {minus}} + H{sub 2}S environments was discussed based upon Auger electron spectroscopy (AES) analysis, and the roles of each alloying element were clarified.

  4. Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

    DOEpatents

    Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

    2014-10-14

    A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

  5. Hydrogen sulfide and PKG in ischemia-reperfusion injury: sources, signaling, accelerators and brakes

    PubMed Central

    Andreadou, Ioanna; Iliodromitis, Efstathios K.; Szabo, Csaba; Papapetropoulos, Andreas

    2015-01-01

    Over the past decade, hydrogen sulfide has emerged as an important cardioprotective molecule with potential for clinical applications. Although several pathways have been proposed to mediate the beneficial effects of H2S, the NO and cGMP axis has attracted significant attention. Recent evidence has suggested that cGMP-dependent protein kinase can lie both downstream and upstream of H2S. The current literature on this topic is reviewed and data from recent studies are integrated to propose a unifying model. PMID:26318600

  6. Evaluation of thiosulfate as a substitute for hydrogen sulfide in sour corrosion fatigue studies

    NASA Astrophysics Data System (ADS)

    Kappes, Mariano Alberto

    This work evaluates the possibility of replacing hydrogen sulfide (H 2S) with thiosulfate anion (S2O32- ) in sour corrosion fatigue studies. H2S increases the corrosion fatigue crack growth rate (FCGR) and can be present in carbon steel risers and flowlines used in off-shore oil production. Corrosion tests with gaseous H2S require special facilities with safety features, because H2S is a toxic and flammable gas. The possibility of replacing H2S with S2O32-, a non-toxic anion, for studying stress corrosion cracking of stainless and carbon steels in H2S solutions was first proposed by Tsujikawa et al. ( Tsujikawa et al., Corrosion, 1993. 49(5): p. 409-419). In this dissertation, Tsujikawa work will be extended to sour corrosion fatigue of carbon steels. H2S testing is often conducted in deareated condition to avoid oxygen reaction with sulfide that yields sulfur and to mimic oil production conditions. Nitrogen deareation was also adopted in S2O3 2- testing, and gas exiting the cell was forced through a sodium hydroxide trap. Measurements of the sulfide content of this trap were used to estimate the partial pressure of H2S in nitrogen, and Henry's law was used to estimate the content of H2S in the solution in the cell. H2S was produced by a redox reaction of S2O 32-, which required electrons from carbon steel corrosion. This reaction is spontaneous at the open circuit potential of steel. Therefore, H2S concentration was expected to be maximum at the steel surface, and this concentration was estimated by a mass balance analysis. Carbon steel specimens exposed to S2O32- containing solutions developed a film on their surface, composed by iron sulfide and cementite. The film was not passivating and a good conductor of electrons. Hydrogen permeation experiments proved that this film controls the rate of hydrogen absorption of steels exposed to thiosulfate containing solutions. The absorption of hydrogen in S2O3 2- solutions was compared with the absorption of hydrogen in solutions saturated with different H2S partial pressures. The partial pressure was selected so that the concentration of H2S in the solution saturated with the gas would be the same as that reached in the surface of steel freely corroding in the thiosulfate solution. For solutions obtained by bubbling H2S, the rate of hydrogen absorption increased with the partial pressure of the gas, but the rate of hydrogen absorption reached a maximum at 10-3 M S2O3 2-, despite the surface concentration of H2S increased with the concentration of S2O32-. This effect was associated with the formation of thicker films, which inhibited the absorption of hydrogen. FCGR were evaluated at constant stress intensity factor range. Crack length was monitored in-situ by the direct current potential drop (DCPD) method. FCGR increased with the partial pressure of H2S in nitrogen. FCGR was controlled not only by the amount of hydrogen present in the steel, but also by inhibiting contributions like crack closure and crack tip blunting. FCGR in dilute thiosulfate solutions was near that measured in a solution saturated with a partial pressure of H2S equal to 0.56 kPa, in accord with hydrogen permeation results.

  7. Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments

    SciTech Connect

    Hara, T.; Asahi, H.

    2000-05-01

    Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

  8. {open_quotes}BIOX{close_quotes} hydrogen sulfide abatement process - application analysis

    SciTech Connect

    Gallup, D.L.

    1996-12-31

    A new hydrogen sulfide abatement process, known as {open_quotes}BIOX,{close_quotes} has been specifically developed for the geothermal industry. {open_quotes}BIOX{close_quotes} (biocide induced oxidation) successfully controls both primary and secondary emissions from cooling towers in pilot, demonstration, and commercial operations by air-wet oxidation. Independent laboratory tests recently controverted the efficacy of {open_quotes}BIOX{close_quotes} to catalytically oxidize sulfides to sulfate. Studies conducted in our laboratory with a simulated cooling tower indicate that the experimental conditions employed by Nardini, et al, are unrealistic for geothermal cooling towers. Furthermore, our investigations demonstrate that the {open_quotes}BIOX{close_quotes} process performs optimally at near neutral pH, a condition common to most geothermal cooling tower circulating water systems. A {open_quotes}BIOX{close_quotes} agent, trichloroisocyanuric acid (TCCA), proved to mitigate sulfide emissions much more efficiently than air, sodium hypochlorite or chlorine dioxide. {open_quotes}BIOX{close_quotes} is a proven, cost-effective H{sub 2}S abatement technology.

  9. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17... Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  10. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17... Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  11. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17... Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  12. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17... Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  13. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  14. Kinetic and thermodynamic studies on the disulfide-bond reducing potential of hydrogen sulfide.

    PubMed

    Vasas, Anita; Dka, va; Fbin, Istvn; Nagy, Pter

    2015-04-30

    The significance of persulfide species in hydrogen sulfide biology is increasingly recognized. However, the molecular mechanisms of their formation remain largely elusive. The obvious pathway of the reduction of biologically abundant disulfide moieties by sulfide was challenged on both thermodynamic and kinetic grounds. Using DTNB (5,5'-dithiobis-(2-nitrobenzoic acid), also known as Ellman's reagent) as a model disulfide we conducted a comprehensive kinetic study for its reaction with sulfide. The bimolecular reaction is relatively fast with a second-order rate constant of 889 12 M(-1)s(-1) at pH = 7.4. pH dependence of the rate law revealed that the reaction proceeds via the bisulfide anion species with an initial nucleophilic thiol-disulfide exchange reaction to give 5-thio-2-nitrobenzoic acid (TNB) and TNB-persulfide with a pH independent second-order rate constant of 1090 12 M(-1)s(-1). However, kinetic studies and stoichiometric analyses in a wide range of reactant ratios together with kinetic simulations revealed that it is a multistep process that proceeds via kinetically driven, practically irreversible reactions along the disulfide ? persulfide ? inorganic polysulfides axis. The kinetic model postulated here, which is fully consistent with the experimental data, suggests that the TNB-persulfide is further reduced by sulfide with a second-order rate constant in the range of 5 10(3)?- 5 10(4) M(-1)s(-1) at pH 7.4 and eventually yields inorganic polysulfides and TNB. The reactions of cystine and GSSG with sulfide were found to be significantly slower and to occur via more complicated reaction schemes. (1)H NMR studies suggest that these reactions also generate Cys-persulfide and inorganic polysulfide species, but in contrast with DTNB, in consecutive equilibrium processes that are sensitive to changes in the reactant and product ratios. Collectively, our results demonstrate that the reaction of disulfides with sulfide is a highly system specific process from both thermodynamic and kinetic aspects, which together with the considerable steady-state concentrations of the reactants in biological systems signifies physiological relevance. PMID:25512332

  15. Removing hydrogen sulfide from wastewater treatment facilities` air process streams with a biotrickling filter

    SciTech Connect

    Morton, R.L.; Caballero, R.C.

    1997-12-31

    Control of hydrogen sulfide (H{sub 2}S) and odor emissions has been a major consideration for many wastewater treatment plants. Many different methods have been and are currently being used for H{sub 2}S and odor control. Most of the current methods involve absorption of H{sub 2}S and odors into a liquid solution or adsorption onto a solid matrix. These methods are either expensive or if not operated correctly can be inefficient. The Los Angeles County Sanitation Districts have developed a biological method to remove odors and H{sub 2}S from different off-gas streams at its main wastewater treatment plant, the Joint Water Pollution Control Plant (JWPCP). This treatment method, which is known as a biotrickling filter, uses a packed contactor device in which the air to be treated is blown through the packing. The H{sub 2}S and odor is removed by a scrubbing solution containing bacteria that is trickled down from the top of the contactor. Different types of column packing media were tested, with a rock-based media being the most effective. The rock media allowed the biotrickling filter to get over 98 percent removal of inlet H{sub 2}S, as long as H{sub 2}S loadings did not exceed 39 g-H{sub 2}S/m{sup 3}-hr (1.1 g-H{sub 2}S/ft{sup 3}-hr). Odor panel analyses indicated that inlet odors were reduced by 99 percent by the biotrickling filter. Due to the success of the research work, a full scale biotrickling filter is being put into operation at the JWPCP. The unit will replace existing caustic scrubbers and will be much less expensive to operate. Current costs to operate a caustic scrubber at the JWPCP is about $1,150 per million m{sup 3} ($33.00 per million ft3) of air treated. The biotrickling filter operational costs would be about one-fifth or $240 per million m{sup 3} ($7.00 per million ft{sup 3}) of air treated.

  16. EFFECTS OF INFUSION OF HUMAN METHEMOGLOBIN SOLUTION FOLLOWING HYDROGEN SULFIDE POISONING

    PubMed Central

    Chenuel, Bruno; Sonobe, Takashi; Haouzi, Philippe

    2015-01-01

    Rationale We have recently reported that infusion of a solution containing methemoglobin (MetHb) during exposure to hydrogen sulfide results in a rapid and large decrease in the concentration of the pool of soluble/diffusible H2S in the blood. However, since the pool of dissolved H2S disappears very quickly after H2S exposure, it is unclear if the ability of MetHb to “trap” sulfide in the blood has any clinical interest and relevance in the treatment of sulfide poisoning. Methods In anesthetized rats, repetition of short bouts of high level of H2S infusions were applied to allow the rapid development of an oxygen deficit. A solution containing methemoglobin (600mg/kg) or its vehicle was administered one minute and a half after the end of H2S intoxication. Results The injection of methemoglobin solution increased methemoglobinemia to about 6%, almost instantly, but was unable to decrease the blood concentration of soluble H2S, which had already vanished at the time of infusion, or to increase combined H2S. In addition H2S-induced O2 deficit and lactate production as well as the recovery of carotid blood flow and blood pressure were similar in treated or control animals. Conclusion Our results do not support the view that administration of MetHb or drugs induced methemoglobinemia during the recovery phase following severe H2S intoxication in sedated rats can restore cellular oxidative metabolism, as the pool of diffusible sulfide, accessible to MetHb, disappears rapidly from the blood after H2S exposure. PMID:25634666

  17. Role of ryanodine receptors in the effects of hydrogen sulfide on transmitter release from the frog motor nerve ending.

    PubMed

    Gerasimova, E V; Yakovleva, O V; Zefirov, A L; Sitdikova, G F

    2013-05-01

    We studied the role of ryanodine receptors in the effects of hydrogen sulfide on transmitter release from frog motor nerve ending. Sodium hydrosulfide (300 ?M), a donor of hydrogen sulfide, reversibly increased the frequency of miniature endplate current without changes in its amplitude-time parameters. These effects were associated with reversible increase in endplate current amplitude, which was abolished by activation of ryanodine receptors of intracellular Ca(2+)stores with caffeine (3 mM) and ryanodine (0.5 ?M). Under conditions of ryanodine receptors blockade with ryanodine (10 ?M), sodium hydrosulfide had no effect on induced transmitter release, but its effects remained unchanged during ryanodine receptors blockade with dantrolene (25 ?M). We concluded that an enhanced acetylcholine release induced by hydrogen sulfide is related to an increase of intracellular Ca(2+)concentration due to activation of ryanodine receptors for intracellular Ca(2+)-pool. PMID:23667860

  18. Measurement, analysis, and modeling of hydrogen sulfide emissions from a swine facility in North Carolina

    NASA Astrophysics Data System (ADS)

    Blunden, Jessica

    Annual global source contributions of sulfur compounds to the natural atmospheric environment are estimated to be 142 x 106 tons. Although not quantified, volatilization from animal wastes may be an important source of gaseous reduced sulfur compounds. Hydrogen sulfide (H2S) is a colorless gas emitted during decomposition of hog manure that produces an offensive "rotten egg" odor. Once released into the atmosphere, H 2S is oxidized and the eventual byproduct, sulfuric acid, may combine with other atmospheric constituents to form aerosol products such as ammonium bisulfate and ammonium sulfate. In recent years, confined animal feeding operations (CAFOs) have increased in size, resulting in more geographically concentrated areas of animals and, subsequently, animal waste. In North Carolina and across the southeastern United States anaerobic waste treatment lagoons are traditionally used to store and treat hog excreta at commercial hog farms. Currently, no state regulations exist for H2S gaseous emissions from animal production facilities in North Carolina and the amount of H2S being emitted into the atmosphere from these potential sources is widely unknown. In response to the need for data, this research initiative has been undertaken in an effort to quantify emissions of H2S from swine CAFOs. An experimental study was conducted at a commercial swine farm in eastern North Carolina to measure hydrogen sulfide emissions from a hog housing unit utilizing a mechanical fan ventilation system and from an on-site waste storage treatment lagoon. A dynamic flow-through chamber system was employed to make lagoon flux measurements. Semi-continuous measurements were made over a one-year period (2004-2005) for a few days during each of the four predominant seasons in order to assess diurnal and temporal variability in emissions. Fan rpm from the barn was continuously measured and flow rates were calculated in order to accurately assess gaseous emissions from the system. Temperature at the fan outlet and static pressure inside the barn were measured. Lagoon samples were collected daily and analyzed for sulfide content. Lagoon parameters, temperature and pH; and atmospheric environmental parameters, ambient temperature, relative humidity, wind speed and ambient hydrogen sulfide concentration were concurrently monitored on-site. The highest barn emissions were measured during the winter and appeared to be related to the age and weight of the animals housed inside the barn. (Abstract shortened by UMI.)

  19. Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour

    PubMed Central

    Jin, Zhuping

    2015-01-01

    Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways. PMID:26078806

  20. Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour.

    PubMed

    Jin, Zhuping; Pei, Yanxi

    2015-01-01

    Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways. PMID:26078806

  1. Unmodified versus caustics-impregnated carbons for control of hydrogen sulfide emissions from sewage treatment plants

    SciTech Connect

    Bandosz, T.J.; Bagreev, A.; Adib, F.; Turk, A.

    2000-03-15

    Unmodified and caustic-impregnated carbons were compared as adsorbents for hydrogen sulfide in the North River Water Pollution Control Plant in New York City over a period of 2 years. The carbons were characterized using accelerated H{sub 2}S breakthrough capacity tests, sorption of nitrogen, potentiometric titration, and thermal analysis. The accelerated laboratory tests indicate that the initial capacity of caustic-impregnated carbons exceeds that of unmodified carbon, but the nature of real-life challenge streams, particularly their lower H{sub 2}S concentrations, nullifies this advantage. As the caustic content of the impregnated carbon is consumed, the situation reverses, and the unmodified carbon becomes more effective. When the concentration of H{sub 2}S is low, the developed surface area and pore volume along with the affinity to retain water create a favorable environment for dissociative adsorption of hydrogen sulfide and its oxidation to elemental sulfur, S{sup 4+}, and S{sup 6+}. In the case of the caustic carbon, the catalytic impact of the carbon surface is limited, and its good performance lasts only while active base is present. The results also show the significant differences in performance of unmodified carbons due to combined effects of their porosity and surface chemistry.

  2. Matrix metalloproteinases in atherosclerosis: role of nitric oxide, hydrogen sulfide, homocysteine, and polymorphisms

    PubMed Central

    Vacek, Thomas P; Rehman, Shahnaz; Neamtu, Diana; Yu, Shipeng; Givimani, Srikanth; Tyagi, Suresh C

    2015-01-01

    Atherosclerosis is an inflammatory process that involves activation of matrix metalloproteinases (MMPs); MMPs degrade collagen and allow for smooth-muscle cell migration within a vessel. Moreover, this begets an accumulation of other cellular material, resulting in occlusion of the vessel and ischemic events to tissues in need of nutrients. Homocysteine has been shown to activate MMPs via an increase in oxidative stress and acting as a signaling molecule on receptors like the peroxisome proliferator activated receptor-γ and N-methyl-D-aspartate receptor. Nitric oxide has been shown to be beneficial in some cases of deactivating MMPs. However, in other cases, it has been shown to be harmful. Further studies are warranted on the scenarios that are beneficial versus destructive. Hydrogen sulfide (H2S) has been shown to decrease MMP activities in all cases in the literature by acting as an antioxidant and vasodilator. Various MMP-knockout and gene-silencing models have been used to determine the function of the many different MMPs. This has allowed us to discern the role that each MMP has in promoting or alleviating pathological conditions. Furthermore, there has been some study into the MMP polymorphisms that exist in the population. The purpose of this review is to examine the role of MMPs and their polymorphisms on the development of atherosclerosis, with emphasis placed on pathways that involve nitric oxide, hydrogen sulfide, and homocysteine. PMID:25767394

  3. Glutathione-garlic sulfur conjugates: slow hydrogen sulfide releasing agents for therapeutic applications.

    PubMed

    Bhuiyan, Ashif Iqbal; Papajani, Vilma Toska; Paci, Maurizio; Melino, Sonia

    2015-01-01

    Natural organosulfur compounds (OSCs) from Allium sativum L. display antioxidant and chemo-sensitization properties, including the in vitro inhibition of tumor cell proliferation through the induction of apoptosis. Garlic water- and oil-soluble allyl sulfur compounds show distinct properties and the capability to inhibit the proliferation of tumor cells. In the present study, we optimized a new protocol for the extraction of water-soluble compounds from garlic at low temperatures and the production of glutathionyl-OSC conjugates during the extraction. Spontaneously, Cys/GSH-mixed-disulfide conjugates are produced by in vivo metabolism of OSCs and represent active molecules able to affect cellular metabolism. Water-soluble extracts, with (GSGaWS) or without (GaWS) glutathione conjugates, were here produced and tested for their ability to release hydrogen sulfide (H2S), also in the presence of reductants and of thiosulfate:cyanide sulfurtransferase (TST) enzyme. Thus, the TST catalysis of the H2S-release from garlic OSCs and their conjugates has been investigated by molecular in vitro experiments. The antiproliferative properties of these extracts on the human T-cell lymphoma cell line, HuT 78, were observed and related to histone hyperacetylation and downregulation of GAPDH expression. Altogether, the results presented here pave the way for the production of a GSGaWS as new, slowly-releasing hydrogen sulfide extract for potential therapeutic applications. PMID:25608858

  4. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    PubMed

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (<10 taxa). Bacterial community composition was not correlated to geographic location when considered independently from other environmental factors. Corrosion was most severe in sites with high levels of hydrogen sulfide (>100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus. PMID:24842376

  5. Reaction-based epoxide fluorescent probe for in vivo visualization of hydrogen sulfide.

    PubMed

    Sathyadevi, Palanisamy; Chen, Yu-Jen; Wu, Shou-Cheng; Chen, Yen-Hao; Wang, Yun-Ming

    2015-06-15

    Hydrogen sulfide (H2S) has emerged as the most important biosynthetic gasotransmitters along with nitric oxide (NO) and carbon monoxide (CO). In this study, we report the design and the synthesis of a new epoxide fluorescent probe 7-glycidyloxy-9-(2-glycidyloxycarbonylphenyl)-2-xanthone (FEPO) for use in in vivo visualization of hydrogen sulfide. The probe employs a fluorescein as a fluorophore, and is equipped with an operating epoxide unit. FEPO functions via epoxide ring opening upon nucleophilic attack of H2S. This ring opening strategy may open a new avenue for the development of various H2S fluorescent sensors. FEPO showed high selectivity and high sensitivity for H2S. FEPO's cytotoxicity was tested using MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide) assay. Furthermore, the use of confocal imaging of H2S and in vivo imaging in live zebra fish demonstrated FEPO's potential biological applications. We anticipate that, owing to their ideal properties, probes of this type will find great uses in exploring the role of H2S in biology. PMID:25660659

  6. Adsorption/oxidation of hydrogen sulfide on nitrogen-containing activated carbons

    SciTech Connect

    Adib, F.; Bagreev, A.; Bandosz, T.J.

    2000-02-22

    Wood-based activated carbon was modified by impregnation with urea and heat treatment at 450 and 950 C. The chemical and physical properties of materials were determined using acid/base titration, FTIR, thermal analysis, IGC, and sorption of nitrogen. The surface features were compared to those of a commercial urea-modified carbon. Then, the H{sub 2}S breakthrough capacity tests were carried out, and the sorption capacity was evaluated. The results showed that urea-modified sorbents have a capacity similar to that of the received material; however, the conversion of hydrogen sulfide to a water-soluble species is significantly higher. It happens due to a high dispersion of basic nitrogen compounds in the small pores of carbons, where oxidation of hydrogen sulfide ions to sulfur radicals followed by the creation of sulfur oxides and sulfuric acid occurs. It is proposed that the process proceeds gradually, from small pores to larger, and that the degree of microporosity is an important factor.

  7. Dual-emissive nanohybrid for ratiometric luminescence and lifetime imaging of intracellular hydrogen sulfide.

    PubMed

    Yu, Qi; Zhang, Kenneth Yin; Liang, Hua; Zhao, Qiang; Yang, Tianshe; Liu, Shujuan; Zhang, Chuanqi; Shi, Zhengjian; Xu, Wenjuan; Huang, Wei

    2015-03-11

    We design a nanohybrid for the detection of hydrogen sulfide (H2S) based on mesoporous silica nanoparticles (MSNs). A phosphorescent iridium(III) complex and a specific H2S-sensitive merocyanine derivative are embedded into the nanohybrid. It exhibits a unique dual emission that is ascribed to the iridium(III) complex and the merocyanine derivative, respectively. Upon addition of sodium hydrogen sulfide (NaHS), the emission from the merocyanine derivative is quenched, while the emission from the iridium(III) complex is almost unchanged, which enables the ratiometric detection of H2S. Additionally, the nanohybrid has a long luminescence lifetime and displays a significant change in luminescence lifetime in response to H2S. Intracellular detection of H2S is performed via ratiometric imaging and photoluminescence lifetime imaging microscopy. Compared with the intensity-based method, the lifetime-based detection is independent of the probe concentration and can efficiently distinguish the signals of the probe from the autofluorescence in complex biological samples. PMID:25692496

  8. [THE ROLE OF HYDROGEN SULFIDE IN REGULATION OF CIRCULATION BLOOD LIVER].

    PubMed

    Yanchuk, P I; Slobodianyk, L A

    2015-01-01

    It was shown in acute experiments on laboratory rats that intraportalinjectionof hydrogen sulfide's precursor L-cysteine (15 mg/kg)caused dilatation of the intrahepatic vessels. As a result, systemic blood pressure (SBP) and blood pressure in the portal vein (PVP) significantly decreased on 17,6 and 24,5%, respectively, and the rate of local blood flow in the liver (LF) and its blood filling (BF) increased on 28,2 and 24,4% respectively. Application of hydrogen sulfide donor NaHS (7 mg/kg) resulted in similarly directed changes: SBP and PVP decreased on 20,8% i 26,2% respectively,LF and BF increased on 16,4% and 30,9% respectively. Application of L-cysteine in the conditions of tsystationin-gamma-lyase blockade by LD-proparhilhlitsyn led to an increase in SBP on 20,4 % and PVP on 26,6% and a decrease of BF on 21,5% and LF in the liver on 11,7% comparing with baseline values of these parameters. So, blockade of tsystationin-gamma-lyase not only completely removed the effects of L-cysteine, but also inhibited synthesis of H2S from its endogenous predecessors,which led to vasoconstriction of liver's blood vessels and, consequently, to an increase of blood pressure and a decrease of liver blood flow rat's and volume of blood deposited in liver. PMID:26495733

  9. Small, high pressure liquid hydrogen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.; Warren, D. J.

    1980-01-01

    A high pressure, low capacity, liquid hydrogen turbopump was designed, fabricated, and tested. The design configuration of the turbopump is summarized and the results of the analytical and test efforts are presented. Approaches used to pin point the cause of poor suction performance with the original design are described and performance data are included with an axial inlet design which results in excellent suction capability.

  10. Liquid hydrogen flow problems in Kiwi reactors

    SciTech Connect

    Thurston, R.S.

    1992-09-01

    The Kiwi series of reactors were the first ones tested in the US Rover Program in the development of nuclear rocket engines for space propulsion. The early experiments with liquid hydrogen showed that parallel flow systems were prone to uneven flow distributions and violent fluctuations in pressure and flow that were capable of destroying a reactor core. Kiwi flow distribution problems were solved by using multiple feed lines into the nozzle cooling system and carefully balancing impedance among them. The violent pressure and flow fluctuations were eliminated after their cause was identified as resonance phenomena driven by the response to flow disturbances of heat transfer through a superheated hydrogen layer. Smooth flow operations were assured by rapidly bringing operating pressures beyond several times the critical pressure of hydrogen. After this initial rough start, solid core nuclear rocket engines successfully passed milestones of achievements during the remainder of the Rover program.

  11. Occurrence and distribution of color and hydrogen sulfide in water of the principal artesian aquifers in the Valdosta area, Georgia

    USGS Publications Warehouse

    Krause, Richard E.

    1976-01-01

    Hydrogen sulfide and color occur in objectionable amounts in ground water from the principal artesian aquifer in the Valdosta , Ga., area. Generally, water from wells south of Valdosta is high in hydrogen sulfide; water from wells north of the city is high in color. Water with high sulfate is likely to be a problem in wells deeper than about 540 ft. Heavy pumpage concentrated in a small area may cause high-sulfate water to migrate vertically upward into shallower wells. (Woodard-USGS)

  12. Geology and petrology of the Voisey's Bay intrusion: reaction of olivine with sulfide and silicate liquids

    NASA Astrophysics Data System (ADS)

    Li, C.; Naldrett, A. J.

    1999-06-01

    The Voisey's Bay Ni-Cu-Co sulfide deposit is located in Eastern Labrador, and transects the 1.85 Ga collisional boundary between interbanded garnet-sillimanite and quartzo-feldspathic paragneisses (Tasuiyak gneisses) of the Proterozoic Churchill Province to the west and granitic, intermediate and mafic orthogneisses of the Archean Nain Province to the east. The deposit is associated with an upper troctolitic chamber (the Eastern Deeps chamber) which is connected to a lower troctolitic chamber (the Reid Brook chamber) by a gabbroic/troctolitic feeder sheet approximately 1 km in vertical extent. Rock sequences that have been defined to date include Leuco-troctolite (LUT) in the Reid Brook chamber, Feeder Breccia (FB) in the Reid Brook Zone, Feeder Olivine Gabbro (FOG), Leopard Troctolite (LT) and Basal Breccia Sequence (BBS) in the feeder sheet, and Olivine Gabbro (OG), Normal Troctolite (NT) and Varied-textured Troctolite (VT) in the Eastern Deeps chamber. Mineralisation has been found in the feeder sheet, as massive stringers in gneisses flanking the feeder, in the `Ovoid', a 600300110 m 3 basin of massive sulfide at surface, and as a zone of massive sulfide that has developed close to the entry of the feeder to the Eastern Deeps chamber. The mineralisation comprises pyrrhotite (both hexagonal and troilite in varying proportions), pentlandite, chalcopyrite, magnetite and minor cubanite. An important component of all mineralized zones is a breccia of gneissic fragments in a troctolitic to noritic matrix referred to as BBS or FB. Considerable reaction has occurred between the troctolite magma and the gneiss inclusions. Olivines in the LUT, OG and FOG have low Ni contents relative to their forsterite (Fo) contents. Olivines in the NT and VT have higher Ni contents but show a great scatter in both their Ni and Fo contents. The Ni content of olivine in the LT increases systematically with decreasing Fo content. All of these variations are explained in terms of fractional crystallisation of magma, sulfide segregation, trapped liquid shift and re-equilibration between sulfide and olivine. Our current understanding of the development of the deposit is that an initial pulse of magma rose to a lower chamber, fractionated to form mafic-ultramafic cumulates and at the same time became sulfide-saturated as a result of interacting with the enclosing, sulfide- and graphite-bearing Tasiuyak gneisses. The magma lost much of its Ni and Cu as it fractionated olivine and segregated sulfides. A new wave of fresh magma entered the lower chamber, forcing the chalcophile-depleted magma, along with some of its contained sulfide, up the feeder to spread out in the upper chamber. Remnants of this chalcophile-depleted magma are preserved as olivine gabbro which forms upper layers in the upper chamber, and which in places has frozen to the walls of the feeder. Sulfides that were swept up in this event were forced out into fractures in the feeder walls, are preserved within thickened zones within the feeder, and were deposited as the magma flow decreased at the entry of the feeder to the upper chamber. Continued influx of the later, undepleted magma resulted in sulfides being picked up, transported farther up the system, upgraded during transportation and then redeposited.

  13. Partitioning of sulfur and selenium between sulfide and silicate liquids and the thermochemistry of sulfide-selenide liquids

    NASA Astrophysics Data System (ADS)

    Wykes, J. L.; O'Neill, H. S.; Mavrogenes, J.

    2014-12-01

    Selenium is a member of group 14 of the periodic table, directly below sulfur, and is generally acknowledged to exhibit similar geochemical behaviour to sulfur, as evidenced by complete solid solution between many sulfur and selenium minerals. However, in certain situations Se shows markedly different geochemical properties to S. In the context of igneous processes, for example, differences in the relative stabilities of Se2-/SeO42- and S2-/SO42- may be useful for unravelling the redox history of convergent margin magmas. Also, Se seems to be more resistant to late-stage degassing from magmas, allowing original S contents to be estimated from observed Se contents and assumed Se/S ratios (e.g. Jenner et al., 2010, Journal of Petrology, 51, 2445-2464). This raises the question of whether the Se/S ratios of these magmas can be assumed to reflect the Se/S ratios in the mantle source (usually assumed to be chondritic), or whether this ratio is fractionated during partial melting. To address this issue, experiments were conducted in the piston-cylinder appratus to investigate the partitioning of S and Se between haplobasaltic silicate liquid and Fe-S-Se liquids near the FeS-FeSe join at 1400-1500 C, 1.0-3.5 GPa and different Se/S ratios. Experimental results show that there is a slightly more compatible in Fe-S-Se liquid with increasing pressure, with KD (XS2- XFeSe)/(XSe2- XFeS) increasing from 2.2 at 0.75 GPa to 2.74 at 3.5 GPa for compositions at molar S/(S+Se) of 0.82. This modest pressure dependence is consistent with earlier experimental results (Rose-Weston et al., 2009, Geochimica et Cosmochimica Acta, 73, 4598-4615). There is no significant temperature dependence over the relatively small temperature range investigated. Activity-composition relations derived from partitioning experiments suggest that FeS-FeSe liquids can be described by a symmetric regular solution model with a small positive deviation from ideality of 7.54 1.16 kJmol-1.

  14. Effect of sulfide removal on sulfate reduction at pH 5 in a hydrogen fed gas-lift bioreactor.

    PubMed

    Bijmans, Martijn F M; Dopson, Mark; Ennin, Frederick; Lens, Piet N L; Buisman, Cees J N

    2008-11-01

    Biotechnological treatment of sulfate- and metal-ionscontaining acidic wastewaters from mining and metallurgical activities utilizes sulfate-reducing bacteria to produce sulfide that can subsequently precipitate metal ions. Reducing sulfate at a low pH has several advantages above neutrophilic sulfate reduction. This study describes the effect of sulfide removal on the reactor performance and microbial community in a high-rate sulfidogenic gas-lift bioreactor fed with hydrogen at a controlled internal pH of 5. Under sulfide removal conditions, 99% of the sulfate was converted at a hydraulic retention time of 24 h, reaching a volumetric activity as high as 51 mmol sulfate/l/d. Under nonsulfide removal conditions, <25% of the sulfate was converted at a hydraulic retention time of 24 h reaching volumetric activities of <13mmol sulfate/l/d. The absence of sulfide removal at a hydraulic retention time of 24 h resulted in an average H2S concentration of 18.2 mM (584 mg S/l). The incomplete sulfate removal was probably due to sulfide inhibition. Molecular phylogenetic analysis identified 11 separate 16S rRNA bands under sulfide stripping conditions, whereas under nonsulfide removal conditions only 4 separate 16S rRNA bands were found. This shows that a less diverse population was found in the presence of a high sulfide concentration. PMID:19047826

  15. The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% Pd-Cu membranes

    SciTech Connect

    Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.D.

    2007-11-15

    The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% PdCu membrane alloys was studied using various H2S-containing gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% PdCu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the PdCu alloy from ideality, probably due to Cu segregation at the membrane surface.

  16. The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% PdCu membranes

    SciTech Connect

    Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.

    2007-11-15

    The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% PdCu membrane alloys was studied using various H2Scontaining gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% PdCu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the PdCu alloy from ideality, probably due to Cu segregation at the membrane surface.

  17. Study of Hydrogen Recovery Systems for Gas Vented While Refueling Liquid-Hydrogen Fueled Aircraft

    NASA Technical Reports Server (NTRS)

    Baker, C. R.

    1979-01-01

    Methods of capturing and reliquefying the cold hydrogen vapor produced during the fueling of aircraft designed to utilize liquid hydrogen fuel were investigated. An assessment of the most practical, economic, and energy efficient of the hydrogen recovery methods is provided.

  18. Partitioning of K, U, and Th between sulfide and silicate liquids - Implications for radioactive heating of planetary cores

    NASA Technical Reports Server (NTRS)

    Murrell, M. T.; Burnett, D. S.

    1986-01-01

    Experimental partitioning studies are reported of K, U, and Th between silicate and FeFeS liquids designed to test the proposal that actinide partitioning into sulfide liquids is more important then K partitioning in the radioactive heating of planetary cores. For a basaltic liquid at 1450 C and 1.5 GPa, U partitioning into FeFeS liquids is five times greater than K partitioning. A typical value for the liquid partition coefficient for U from a granitic silicate liquid at one atmosphere at 1150 C and low fO2 is about 0.02; the coefficient for Th is similar. At low fO2 and higher temperature, experiments with basaltic liquids produce strong Ca and U partitioning into the sulfide liquid with U coefficient greater than one. The Th coefficient is less strongly affected.

  19. Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

    PubMed

    Sun, J L; Shang, C; Kikkert, G A

    2013-01-01

    A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen. PMID:24355850

  20. Experimental partitioning of Sc, Ti, V, Cr, and Mn between iron sulfide and silicate liquids and iron

    SciTech Connect

    Maclean, W.H.; Walker, D.A.

    1985-01-01

    Experiments on the partitioning of Sc, Ti, V, Cr and Mn between immiscible silicate and sulfide liquids saturated with iron were run in alumina containers in sealed, evacuated silica glass capsules using a vertical resistance furnace, 30 minute run duration, and a NaCl brine quench. The system studied was FeS-FeO-SiO/sub 2/ at 1150/sup 0/C, 10 C/sup 0/ above the invariant temperature for the assemblage fayalite-tridymite-sulfide liquid-silicate liquid-iron. Immiscible sulfide and silicate liquids and iron were the primary phases in each run. fS/sub 2/ and fO/sub 2/ are low and internally buffered by the invariant assemblage. Microprobe analyses, using a 20 micron moving beam and 60-100 seconds counting times, yielded partition coefficients (K/sub Me/ = wt% metal in silicate liquid/wt % metal in sulfide liquid): Sc > 100, Ti = 96, V = 6.4, Cr approx. 4, Mn = 7.2. Partitioning in this particular group of transition metals is a complex function of valence states, ionic radii, ligand field effects, and coordination sites. The metals were not detected in either equilibrium of quench crystals of iron. The data explain the lack of these elements in magmatic Ni-Cu PGE ores. In particular, ilmenite, ulvoespinel, vanadiniferous magnetite or chrome spinel may be a phase of the co-magmatic silicate rocks, but only a relatively pure magnetite forms in the sulfide ore.

  1. Experiments on microjets of undercooled liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Fernndez, Jos M.; Khnel, Matthias; Tejeda, Guzmn; Kalinin, Anton; Grisenti, Robert E.; Montero, Salvador

    2012-11-01

    Novel experiments on liquid microjets (filaments) of hydrogen and deuterium, carried out at the Laboratory of Molecular Fluid Dynamics of the IEM, are reported. These filaments, less than 10 microns in diameter, are an ideal medium to produce highly undercooled liquid samples and to investigate the homogeneous solidification process, free from wall effects. The filaments exit from cryogenic capillary nozzles into a vacuum chamber, to cool down very fast by surface evaporation. Finite size radius leads to a temperature gradient across the filament, determined by thermal conductivity, and, possibly, to a velocity gradient as well. The filaments are monitored by laser shadowgraphy, and analyzed by means of high performance Raman spectroscopy. Real-time measurements in the rotational and vibrational spectral regions reveal the structure and temperature along the filaments, allowing to track the crystal growth process. The high spatial resolution of Raman spectroscopy allows observing in situ the structural changes of the liquid microjets, with a time resolution of 10 ns. The filaments of pure para-H2 can be cooled down to 9 K (65% of its melting point at 13.8 K), while staying liquid, before eventually solidifying into a metastable polymorph. Crystallization kinetics revealed a growth rate of 33 cm/s, much higher than expected for a thermally activated process. The time and spatial control attained in these experiments offers new opportunities for investigating the processes of nonequilibrium phase transformations in undercooled fluids, as well as the propagation of liquid jets into a rarefied gas media.

  2. Screen Channel Liquid Acquisition Device Outflow Tests in Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Hartwig, Jason W.; Chato, David J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

    2013-01-01

    This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3 - 24.2 K), pressures (100 - 350 kPa), and flow rates (0.010 - 0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

  3. Electrically Conducting Polymer-Copper Sulphide Composite Films, Preparation by Treatment of Polymer-Copper (2) Acetate Composites with Hydrogen Sulfide

    NASA Technical Reports Server (NTRS)

    Yamamoto, Takakazu; Kamigaki, Takahira; Kubota, Etsuo

    1988-01-01

    Polymer copper sulfide composite films were prepared by treatment of polymer poly(vinyl chloride), poly(acrylonitrile), copolymer of vinyl chloride and vinyl acetate (90:10), and ABS resin copper (2) acetate composites with hydrogen sulfide. The films showed electrical conductivity higher than 0.015 S/cm when they contained more than 20 wt percent of copper sulfide. A poly(acrylonitrile)-copper sulfide composite film containing 40 to 50 wt percent of copper sulfide showed electrical conductivity of 10 to 150.0 S/cm and had relatively high mechanical strength to be used in practical purposes.

  4. 75 FR 19319 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension of Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... Number (CAS No.) 7783-06-4) (75 FR 8889). The purpose of today's action is to inform interested parties... requirements for hydrogen sulfide (75 FR 8889). B. Why and for How Long Is EPA Extending the Comment Period..., 212231, 212234, 212299 (correspond to SIC 10, Metal Mining (except 1011, 1081, and 1094)); or...

  5. Inhibitory Effects of Condensed Tannins on Sulfate-Reducing Bacteria Populations and Hydrogen Sulfide Production from Swine Manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous compounds and emissions associated with consolidated storage of swine manure are produced as a result of anaerobic microbial digestion of materials present in the manure. Hydrogen sulfide (H2S) is one such offensive and toxic odorant that can reach hazardous levels during manure storage and...

  6. DECHLORINATION OF CHLOROPICRIN AND 1,3-DICHLOROPROPENE BY HYDROGEN SULFIDE SPECIES: REDOX AND NUCLEOPHILIC SUBSTITUTION REACTIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chlorinated fumigants chloropicrin and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soil-borne pests. Reaction of these two fumigants with hydrogen sulfide species (H2S and HS ) was examined in well-defined anoxic aqueous solutions. Chloropicrin ...

  7. Borax and Octabor Treatment of Stored Swine Manure: Reduction in Hydrogen Sulfide Emissions and Phytotoxicity to Agronomic Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gaseous emissions from stored manure have become environmental and health issues for humans and animals as the livestock industry becomes specialized and concentrated. Of particular concern is hydrogen sulfide, which is being targeted for regulatory control in concentrated animal farm operations. ...

  8. Combined borax and tannin treatment of stored dairy manure to reduce bacterial populations and hydrogen sulfide emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Anaerobic digestion of organic residues in stored livestock manure is associated with the production of odors and emissions. Hydrogen sulfide (H2S) is one such emission that can reach hazardous levels during manure storage and handling, posing a risk to both farmers and livestock. New te...

  9. Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Odorous gas emissions from stored swine manure are becoming serious environmental and health issues as the livestock industry becomes more specialized, concentrated, and industrialized. These nuisance gasses include hydrogen sulfide (H2S), ammonia, and methane, which are produced as a result of ana...

  10. AMMONIA AND HYDROGEN SULFIDE FLUX AND DRY DEPOSITION VELOCITY ESTIMATES USING VERTICAL GRADIENT METHOD AT A COMMERCIAL BEEF CATTLE FEEDLOT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia and hydrogen sulfide flux and dry deposition velocity were estimated using micrometeorological vertical gradient flux method at a commercial cattle feedyard of approximately 50,000 head of beef cattle and average 14.4 m2/head (150 ft2/head) stocking density. During summertime, NH3-N emission...

  11. Protective effects of hydrogen sulfide anions against acetaminophen-induced hepatotoxicity in mice.

    PubMed

    Ishii, Isao; Kamata, Shotaro; Hagiya, Yoshifumi; Abiko, Yumi; Kasahara, Tadashi; Kumagai, Yoshito

    2015-01-01

    The key mechanism for hepatotoxicity resulting from acetaminophen (APAP) overdose is cytochrome P450-dependent formation of N-acetyl-p-benzoquinone imine (NAPQI), a potent electrophilic metabolite that forms protein adducts. The fundamental roles of glutathione in the effective conjugation/clearance of NAPQI have been established, giving a molecular basis for the clinical use of N-acetylcysteine as a sole antidote. Recent evidence from in vitro experiments suggested that sulfide anions (S(2-)) to yield hydrogen sulfide anions (HS(-)) under physiological pH could effectively react with NAPQI. This study evaluated the protective roles of HS(-) against APAP-induced hepatotoxicity in mice. We utilized cystathionine ?-lyase-deficient (Cth(-/-)) mice that are highly sensitive to acetaminophen toxicity. Intraperitoneal injection of acetaminophen (150 mg/kg) into Cth(-/-) mice resulted in highly elevated levels of serum alanine/aspartate aminotransferases and lactate dehydrogenase associated with marked increases in oncotic hepatocytes; all of which were significantly inhibited by intraperitoneal preadministration of sodium hydrosulfide (NaHS). NaHS preadministration significantly suppressed APAP-induced serum malondialdehyde level increases without abrogating APAP-induced rapid depletion of hepatic glutathione. These results suggest that exogenous HS(-) protects hepatocytes by directly scavenging reactive NAPQI rather than by increasing cystine uptake and thereby elevating intracellular glutathione levels, which provides a novel therapeutic approach against acute APAP poisoning. PMID:26558465

  12. Hydrogen Sulfide Signaling Axis as a Target for Prostate Cancer Therapeutics

    PubMed Central

    Liu, Mingzhe; Wu, Lingyun; Montaut, Sabine; Yang, Guangdong

    2016-01-01

    Hydrogen sulfide (H2S) was originally considered toxic at elevated levels; however just in the past decade H2S has been proposed to be an important gasotransmitter with various physiological and pathophysiological roles in the body. H2S can be generated endogenously from L-cysteine by multiple enzymes, including cystathionine gamma-lyase, cystathionine beta-synthase, and 3-mercaptopyruvate sulfurtransferase in combination with cysteine aminotransferase. Prostate cancer is a major health concern and no effective treatment for prostate cancers is available. H2S has been shown to inhibit cell survival of androgen-independent, androgen-dependent, and antiandrogen-resistant prostate cancer cells through different mechanisms. Various H2S-releasing compounds, including sulfide salts, diallyl disulfide, diallyl trisulfide, sulforaphane, and other polysulfides, also have been shown to inhibit prostate cancer growth and metastasis. The expression of H2S-producing enzyme was reduced in both human prostate cancer tissues and prostate cancer cells. Androgen receptor (AR) signaling is indispensable for the development of castration resistant prostate cancer, and H2S was shown to inhibit AR transactivation and contributes to antiandrogen-resistant status. In this review, we summarized the current knowledge of H2S signaling in prostate cancer and described the molecular alterations, which may bring this gasotransmitter into the clinic in the near future for developing novel pharmacological and therapeutic interventions for prostate cancer.

  13. Impact of fermentation rate changes on potential hydrogen sulfide concentrations in wine.

    PubMed

    Butzke, Christian E; Park, Seung Kook

    2011-05-01

    The correlation between alcoholic fermentation rate, measured as carbon dioxide (CO2) evolution, and the rate of hydrogen sulfide (H2S) formation during wine production was investigated. Both rates and the resulting concentration peaks in fermentor headspace H2S were directly impacted by yeast assimilable nitrogenous compounds in the grape juice. A series of model fermentations was conducted in temperature-controlled and stirred fermentors using a complex model juice with defined concentrations of ammonium ions and/or amino acids. The fermentation rate was measured indirectly by noting the weight loss of the fermentor; H2S was quantitatively trapped in realtime using a pre-calibrated H2S detection tube which was inserted into a fermentor gas relief port. Evolution rates for CO2 and H2S as well as the relative ratios between them were calculated. These fermentations confirmed that total sulfide formation was strongly yeast strain-dependent, and high concentrations of yeast assimilable nitrogen did not necessarily protect against elevated H2S formation. High initial concentrations of ammonium ions via addition of diammonium phosphate (DAP) caused a higher evolution of H2S when compared with a non-supplemented but nondeficient juice. It was observed that the excess availability of a certain yeast assimilable amino acid, arginine, could result in a more sustained CO2 production rate throughout the wine fermentation. The contribution of yeast assimilable amino acids from conventional commercial yeast foods to lowering of the H2S formation was marginal. PMID:21617350

  14. Postsynthetic modification of metal-organic framework for hydrogen sulfide detection

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Zhang, Jianmin; Hu, Quan; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-11-01

    Hydrogen sulfide (H2S) has recently been identified as the third biological gaseous messenger (gasotransmitter) that is involved in regulating many important physiological processes. The detection of H2S is thus essential for its roles but remain challenging in living systems. We report herein a novel turn-on fluorescent probe for H2S detection based on azide functionalized metal-organic framework (MOF). The MOF probe displayed high sensitivity (detection limit, 28.3 ?M), excellent selectivity, and fast response (<2 min) toward H2S over other biologically relevant species. We envisage that this MOF probe can be employed as a useful tool to further elucidate the biological roles of H2S.

  15. Design, Synthesis, and Cardioprotective Effects of N-Mercapto-Based Hydrogen Sulfide Donors.

    PubMed

    Zhao, Yu; Yang, Chuntao; Organ, Chelsea; Li, Zhen; Bhushan, Shashi; Otsuka, Hiro; Pacheco, Armando; Kang, Jianming; Aguilar, Hector C; Lefer, David J; Xian, Ming

    2015-09-24

    Hydrogen sulfide (H2S) is a signaling molecule which plays regulatory roles in many physiological and/or pathological processes. Therefore, regulation of H2S levels could have great potential therapeutic value. In this work, we report the design, synthesis, and evaluation of a class of N-mercapto (N-SH)-based H2S donors. Thirty-three donors were synthesized and tested. Our results indicated that controllable H2S release from these donors could be achieved upon structural modifications. Selected donors (NSHD-1, NSHD-2, and NSHD-6) were tested in cellular models of oxidative damage and showed significant cytoprotective effects. Moreover, NSHD-1 and NSHD-2 were also found to exhibit potent protective effects in a murine model of myocardial ischemia reperfusion (MI/R) injury. PMID:26317692

  16. Production of the gaseous signal molecule hydrogen sulfide in mouse tissues

    PubMed Central

    Linden, David R.; Sha, Lei; Mazzone, Amelia; Stoltz, Gary J.; Bernard, Cheryl E.; Furne, Julie K.; Levitt, Michael D.; Farrugia, Gianrico; Szurszewski, Joseph H.

    2010-01-01

    The gaseous molecule hydrogen sulfide (H2S) has been proposed as an endogenous signal molecule and neuromodulator in mammals. Using a newly developed method, we report here for the first time the ability of intact and living brain and colonic tissue in the mouse to generate and release H2S. This production occurs through the activity of two enzymes, cysthionine-?-lyase (CSE) and cysthionine-?-synthase (CBS). The quantitative expression of messenger RNA and protein localization for both enzymes are described in the liver, brain and colon. Expression levels of the enzymes vary between tissues and are differentially distributed. The observation that tissues that respond to exogenously applied H2S can endogenously generate the gas strongly supports its role as an endogenous signal molecule. PMID:18513201

  17. Kinetics of the reaction of hydrogen sulfide and sulfur dioxide in organic solvents

    SciTech Connect

    Neumann, D.W.; Lynn, S.

    1986-01-01

    Calorimetry was used to study the kinetics of the irreversible reaction between hydrogen sulfide and sulfur dioxide in mixtures of N,N-dimethylaniline (DMA) and diethylene glycol monomethyl ether (DGM) and of DMA and triethylene glycol dimethyl ether (triglyne). The reaction was found to be first order in both H/sub 2/S and SO/sub 2/ in the presence of DMA. The approximate heat of reaction is 28 kcal/mol of sulfur dioxide. The addition of DMA accelerates the reaction by an order of magnitude over that obtained in the glycol ethers alone. Rate constants are in the range of 1-20 L/(mol s). Hydroxylated species such as water, methanol, and other alcohols increase the rate still more dramatically when added to the DMA/ether mixtures. The results of these experiments show some of the effects of solvent composition on the kinetics of the reaction.

  18. Intravital Microscopic Methods to Evaluate Anti-inflammatory Effects and Signaling Mechanisms Evoked by Hydrogen Sulfide

    PubMed Central

    Zuidema, Mozow Y.; Korthuis, Ronald J.

    2016-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous signaling molecule with potent anti-inflammatory properties. Exogenous application of H2S donors, administered either acutely during an inflammatory response or as an antecedent preconditioning intervention that invokes the activation of anti-inflammatory cell survival programs, effectively limits leukocyte rolling, adhesion and emigration, generation of reactive oxygen species, chemokine and cell adhesion molecule expression, endothelial barrier disruption,capillary perfusion deficits, and parenchymal cell dysfunction and injury. This chapter focuses on intravital microscopic methods that can be used to assess the anti-inflammatory effects exerted by H2S, as well as to explore the cellular signaling mechanisms by which this gaseous molecule limits the aforementioned inflammatory responses. Recent advances include use of intravital multiphoton microscopy and optical biosensor technology to explore signaling mechanisms in vivo. PMID:25747477

  19. Homocysteine in renovascular complications: hydrogen sulfide is a modulator and plausible anaerobic ATP generator

    PubMed Central

    Sen, Utpal; Pushpakumar, Sathnur B.; Amin, Matthew A.; Tyagi, Suresh C.

    2014-01-01

    Homocysteine (Hcy) is a non-protein amino acid derived from dietary methionine. High levels of Hcy, known as hyperhomocysteinemia (HHcy) is known to cause vascular complications. In the mammalian tissue, Hcy is metabolized by transsulfuration enzymes to produce hydrogen sulfide (H2S). H2S, a pungent smelling gas was previously known for its toxic effects in the central nervous system, recent studies however has revealed protective effects in a variety of diseases including hypertension, diabetes, inflammation, atherosclerosis, and renal disease progression and failure. Interestingly, under stress conditions including hypoxia, H2S can reduce metabolic demand and also act as a substrate for ATP production. This review highlights some of the recent advances in H2S research as a potential therapeutic agent targeting renovascular diseases associated with HHcy. PMID:24963795

  20. Hydrogen Sulfide, the Next Potent Preventive and Therapeutic Agent in Aging and Age-Associated Diseases

    PubMed Central

    Zhang, Yuan; Tang, Zhi-Han; Ren, Zhong; Qu, Shun-Lin; Liu, Mi-Hua; Liu, Lu-Shan

    2013-01-01

    Hydrogen sulfide (H2S) is the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide. It is physiologically generated by cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase. H2S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems. Substantial evidence shows that H2S is involved in aging by inhibiting free-radical reactions, activating SIRT1, and probably interacting with the age-related gene Klotho. Moreover, H2S has been shown to have therapeutic potential in age-associated diseases. This article provides an overview of the physiological functions and effects of H2S in aging and age-associated diseases, and proposes the potential health and therapeutic benefits of H2S. PMID:23297346

  1. Doubly differential and integral cross sections for electron elastic scattering by hydrogen sulfide

    NASA Astrophysics Data System (ADS)

    Aouchiche, H.; Medegga, F.; Champion, C.

    2014-08-01

    Theoretical doubly differential and integral cross sections for elastic scattering of electrons by hydrogen sulfide vapor are here reported for impact energies ranging from 10 eV to 10 keV. The calculations are carried out within the partial-wave formalism by means of a spherical complex optical potential model taking into account a static contribution deduced from a single-center Hartree-Fock target description as well as correlation-polarization and exchange effects. The results clearly point out the role played by the exchange and the correlation-polarization in particular at low incident energies and around the observed minima. Both doubly differential and integral cross sections are finally compared with a large set of experimental data and a satisfactory agreement is observed.

  2. Systematization of published spectral data on deuterated isotopologues of hydrogen sulfide molecule

    NASA Astrophysics Data System (ADS)

    Voronina, S. S.; Naumenko, O. V.; Polovtseva, E. R.; Fazliev, A. Z.

    2014-11-01

    The report presents a description of properties of published data on spectral lines parameters of deuterated isotopologues of hydrogen sulfide - HDS, HD34S, D2S, D2 34S. Properties values characterizing data quality are calculated taking into account the validity criteria and credit estimation according to publishing criteria. Formalized criteria of data check based on the constraints and selection rules known from the vibrational-rotational theory, as well as an expert evaluation are utilized for validation of the original experimental transitions and energy levels. The consistent and accurate set of the vibration - rotation (VR) energy levels is derived based on the cleaned transitions. Published vibrational-rotational transitions and energy levels of considered molecules as well as the knowledge base are available in the Internet in W@DIS information system (IS).

  3. An Anticancer Role of Hydrogen Sulfide in Human Gastric Cancer Cells

    PubMed Central

    Qi, Qi; Yang, Jianqiang; Sun, Dongsheng; Li, Chunfeng; Xue, Yingwei; Jiang, Qiuying; Tian, Ye; Xu, Changqing; Wang, Rui

    2015-01-01

    Hydrogen sulfide (H2S) can be synthesized in mammalian cells by cystathionine ?-lyase (CSE) and/or cystathionine ?-synthase (CBS). Both CSE and CBS are expressed in rat gastric tissues but their role in human gastric neoplasia has been unclear. The aims of the present study were to detect CSE and CBS proteins in human gastric cancer and determine the effect of exogenous NaHS on the proliferation of gastric cancer cells. We found that both CSE and CBS proteins were expressed in human gastric cancer cells and upregulated in human gastric carcinoma mucosa compared with those in noncancerous gastric samples. NaHS induced apoptosis of gastric cancer cells by regulating apoptosis related proteins. Also, NaHS inhibited cancer cell migration and invasion. An antigastric cancer role of H2S is thus indicated. PMID:26078811

  4. Chronic exposure to low concentrations of hydrogen sulfide produces abnormal growth in developing cerebellar Purkinje cells.

    PubMed

    Hannah, R S; Roth, S H

    1991-01-28

    Hydrogen sulfide (H2S) may produce deleterious effects on the developing central nervous system. The dendritic fields of developing cerebellar Purkinje cells were analyzed to determine the effects of chronic exposure to low concentrations of H2S during perinatal development. Treatment with two concentrations (20 and 50 ppm) of H2S produced severe alterations in the architecture and growth characteristics of the Purkinjec cell dendritic fields. The architectural modifications included longer branches, an increase in the vertex path length and variations in the number of branches in particular areas of the dendritic field. The treated cells also exhibited a nonsymmetrical growth pattern at a time when random terminal branching is normally occurring. These findings suggest that developing neurons exposed to low concentrations of H2S are at risk of severe deficits. PMID:2027523

  5. Hydrogen sulfide and inflammation: the good, the bad, the ugly and the promising.

    PubMed

    Whiteman, Matthew; Winyard, Paul G

    2011-01-01

    Hydrogen sulfide is rapidly gaining ground as a physiological mediator of inflammation, but there is no clear consensus as to its precise role in inflammatory signaling. This article discusses the disparate anti-inflammatory ('the good') and proinflammatory ('the bad') effects of endogenous and pharmacological H(2)S in disparate animal model and cell culture systems. We also discuss 'the ugly', such as problems of using wholly specific inhibitors of enzymatic H(2)S synthesis, and the use of pharmacological donor compounds, which release H(2)S too quickly to be physiologically representative of endogenous H(2)S synthesis. Furthermore, recently developed slow-release H(2)S donors, which offer a more physiological approach to understanding the complex role of H(2)S in acute and chronic inflammation ('the promising') are discussed. PMID:22115346

  6. Hydrogen sulfide, the next potent preventive and therapeutic agent in aging and age-associated diseases.

    PubMed

    Zhang, Yuan; Tang, Zhi-Han; Ren, Zhong; Qu, Shun-Lin; Liu, Mi-Hua; Liu, Lu-Shan; Jiang, Zhi-Sheng

    2013-03-01

    Hydrogen sulfide (H(2)S) is the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide. It is physiologically generated by cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase. H(2)S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems. Substantial evidence shows that H(2)S is involved in aging by inhibiting free-radical reactions, activating SIRT1, and probably interacting with the age-related gene Klotho. Moreover, H(2)S has been shown to have therapeutic potential in age-associated diseases. This article provides an overview of the physiological functions and effects of H(2)S in aging and age-associated diseases, and proposes the potential health and therapeutic benefits of H(2)S. PMID:23297346

  7. Cobalt sulfide nanosheet/graphene/carbon nanotube nanocomposites as flexible electrodes for hydrogen evolution.

    PubMed

    Peng, Shengjie; Li, Linlin; Han, Xiaopeng; Sun, Wenping; Srinivasan, Madhavi; Mhaisalkar, Subodh G; Cheng, Fangyi; Yan, Qingyu; Chen, Jun; Ramakrishna, Seeram

    2014-11-10

    Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on cobalt sulfide/reduced graphene oxide/carbon nanotube (CoS2 /RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the hydrogen evolution reaction. The synergistic effect of CoS2 , graphene, and CNTs leads to unique CoS2 /RGO-CNT nanoarchitectures, the HER activity of which is among the highest for non-noble metal electrocatalysts, showing 10?mA?cm(-2) current density at about 142?mV overpotentials and a high electrochemical stability. PMID:25297454

  8. Hydrogen Sulfide Regulates Inward-Rectifying K+ Channels in Conjunction with Stomatal Closure1[OPEN

    PubMed Central

    Papanatsiou, Maria; Scuffi, Denisse; Blatt, Michael R.; Garca-Mata, Carlos

    2015-01-01

    Hydrogen sulfide (H2S) is the third biological gasotransmitter, and in animals, it affects many physiological processes by modulating ion channels. H2S has been reported to protect plants from oxidative stress in diverse physiological responses. H2S closes stomata, but the underlying mechanism remains elusive. Here, we report the selective inactivation of current carried by inward-rectifying K+ channels of tobacco (Nicotiana tabacum) guard cells and show its close parallel with stomatal closure evoked by submicromolar concentrations of H2S. Experiments to scavenge H2S suggested an effect that is separable from that of abscisic acid, which is associated with water stress. Thus, H2S seems to define a unique and unresolved signaling pathway that selectively targets inward-rectifying K+ channels. PMID:25770153

  9. Hydrogen Sulfide as an Endogenous Modulator in Mitochondria and Mitochondria Dysfunction

    PubMed Central

    Guo, Wei; Kan, Jun-tao; Cheng, Ze-yu; Chen, Jie-fang; Shen, Ya-qi; Xu, Jie; Wu, Dan; Zhu, Yi-zhun

    2012-01-01

    Hydrogen sulfide (H2S) has historically been considered to be a toxic gas, an environmental and occupational hazard. However, with the discovery of its presence and enzymatic production through precursors of L-cysteine and homocysteine in mammalian tissues, H2S has recently received much interest as a physiological signaling molecule. H2S is a gaseous messenger molecule that has been implicated in various physiological and pathological processes in mammals, including vascular relaxation, angiogenesis, and the function of ion channels, ischemia/reperfusion (I/R), and heart injury. H2S is an endogenous neuromodulator and present studies show that physiological concentrations of H2S enhance NMDA receptor-mediated responses and aid in the induction of hippocampal long-term potentiation. Moreover, in the field of neuronal protection, physiological concentrations of H2S in mitochondria have many favorable effects on cytoprotection. PMID:23304257

  10. A Hypothesis: Hydrogen Sulfide Might Be Neuroprotective against Subarachnoid Hemorrhage Induced Brain Injury

    PubMed Central

    Yu, Yong-Peng; Chi, Xiang-Lin; Liu, Li-Jun

    2014-01-01

    Gases such as nitric oxide (NO) and carbon monoxide (CO) play important roles both in normal physiology and in disease. Recent studies have shown that hydrogen sulfide (H2S) protects neurons against oxidative stress and ischemia-reperfusion injury and attenuates lipopolysaccharides (LPS) induced neuroinflammation in microglia, exhibiting anti-inflammatory and antiapoptotic activities. The gas H2S is emerging as a novel regulator of important physiologic functions such as arterial diameter, blood flow, and leukocyte adhesion. It has been known that multiple factors, including oxidative stress, free radicals, and neuronal nitric oxide synthesis as well as abnormal inflammatory responses, are involved in the mechanism underlying the brain injury after subarachnoid hemorrhage (SAH). Based on the multiple physiologic functions of H2S, we speculate that it might be a promising, effective, and specific therapy for brain injury after SAH. PMID:24707204

  11. Inhaled hydrogen sulfide protects against lipopolysaccharide-induced acute lung injury in mice

    PubMed Central

    2012-01-01

    Background Local pulmonary and systemic infections can lead to acute lung injury (ALI). The resulting lung damage can evoke lung failure and multiple organ dysfunction associated with increased mortality. Hydrogen sulfide (H2S) appears to represent a new therapeutic approach to ALI. The gas has been shown to mediate potent anti-inflammatory and organ protective effects in vivo. This study was designed to define its potentially protective role in sepsis-induced lung injury. Methods C57BL/6 N mice received lipopolysaccharide (LPS) intranasally in the absence or presence of 80 parts per million H2S. After 6 h, acute lung injury was determined by comparative histology. Bronchoalveolar lavage (BAL) fluid was analyzed for total protein content and differential cell counting. BAL and serum were further analyzed for interleukin-1β, macrophage inflammatory protein-2, and/or myeloperoxidase glycoprotein levels by enzyme-linked immunosorbent assays. Differences between groups were analyzed by one way analysis of variance. Results Histological analysis revealed that LPS instillation led to increased alveolar wall thickening, cellular infiltration, and to an elevated ALI score. In the presence of H2S these changes were not observed despite LPS treatment. Moreover, neutrophil influx, and pro-inflammatory cytokine release were enhanced in BAL fluid of LPS-treated mice, but comparable to control levels in H2S treated mice. In addition, myeloperoxidase levels were increased in serum after LPS challenge and this was prevented by H2S inhalation. Conclusion Inhalation of hydrogen sulfide protects against LPS-induced acute lung injury by attenuating pro-inflammatory responses. PMID:23025523

  12. Application of bacteriophages specific to hydrogen sulfide-producing bacteria in raw poultry by-products.

    PubMed

    Gong, Chao; Liu, Xiaohua; Jiang, Xiuping

    2014-03-01

    Hydrogen sulfide-producing bacteria (SPB) can spoil raw animal materials and release harmful hydrogen sulfide (H2S) gas. The objective of this study was to apply a SPB-specific bacteriophage cocktail to control H2S production by SPB in different raw poultry by-products in the laboratory (20, 30, and 37C) and greenhouse (average temperature 29 to 31C, humidity 34.8 to 59.8%, and light intensity 604.8 Wm(2)) by simulating transportation and a rendering facility. The amount of H2S production was determined using either test strips impregnated with lead acetate or a H2S monitor. In the laboratory, phage treatment applied to fresh chicken meat inoculated with SPB, spoiled chicken meat, chicken guts, and chicken feathers reduced H2S production by approximately 25 to 69% at temperatures from 20 to 37C. In the greenhouse, phage treatment achieved approximately a 30 to 85% reduction of H2S yield in chicken offal and feathers. Among all phage treatments, multiplicity of infection (MOI) of 100 exhibited the highest inhibitory activities against SPB on H2S production. Several factors such as initial SPB level, temperature, and MOI affect lytic activities of bacteriophages. Our study demonstrated that the phage cocktail is effective to reduce the production of H2S by SPB significantly in raw animal materials. This biological control method can control SPB in raw poultry by-products at ambient temperatures, leading to a safer working environment and high quality product with less nutrient degradation for the rendering industry. PMID:24604865

  13. Hydrogen Sulfide in the RVLM and PVN has No Effect on Cardiovascular Regulation

    PubMed Central

    Streeter, Eloise; Al-Magableh, Mohammad; Hart, Joanne Louise; Badoer, Emilio

    2011-01-01

    Hydrogen sulfide (H2S) is now recognized as an important signaling molecule and has been shown to have vasodilator and cardio-protectant effects. More recently it has been suggested that H2S may also act within the brain to reduce blood pressure (BP). In the present study we have demonstrated the presence of the H2S-producing enzyme, cystathionine-?-synthase (CBS) in the rostral ventrolateral medulla (RVLM), and the hypothalamic paraventricular nucleus (PVN), brain regions with key cardiovascular regulatory functions. The cardiovascular role of H2S was investigated by determining the BP, heart rate (HR), and lumbar sympathetic nerve activity (LSNA) responses elicited by a H2S donor sodium hydrogen sulfide (NaHS) or inhibitors of CBS, microinjected into the RVLM and PVN. In anesthetized Wistar Kyoto rats bilateral microinjections of NaHS (0.22000?pmol/side) into the RVLM did not significantly affect BP, HR, or LSNA, compared to vehicle. Similarly, when the CBS inhibitors, amino-oxyacetate (AOA; 0.11.0?nmol/side) or hydroxylamine (HA; 0.22.0?nmol/side), were administered into the RVLM, there were no significant effects on the cardiovascular variables compared to vehicle. Microinjections into the PVN of NaHS, HA, and AOA had no consistent significant effects on BP, HR, or LSNA compared to vehicle. We also investigated the cardiovascular responses to NaHS microinjected into the RVLM and PVN in spontaneously hypertensive rats. Again, there were no significant effects on BP, HR, and LSNA. Together, these results suggest that H2S in the RVLM and PVN does not have a major role in cardiovascular regulation. PMID:21941511

  14. Evidence that hydrogen sulfide exerts antinociceptive effects in the gastrointestinal tract by activating KATP channels.

    PubMed

    Distrutti, Eleonora; Sediari, Luca; Mencarelli, Andrea; Renga, Barbara; Orlandi, Stefano; Antonelli, Elisabetta; Roviezzo, Fiorenza; Morelli, Antonio; Cirino, Giuseppe; Wallace, John L; Fiorucci, Stefano

    2006-01-01

    Hydrogen sulfide (H(2)S) functions as a neuromodulator, but whether it modulates visceral perception and pain is unknown. Cystathionine beta-synthase (CBS) and cystathionine-gamma-lyase (CSE) mediate enzymatic generation of H(2)S in mammalian cells. Here we have investigated the role of H(2)S in modulating nociception to colorectal distension, a model that mimics some features of the irritable bowel syndrome. Four graded (0.4-1.6 ml of water) colorectal distensions (CRDs) were produced in conscious rats (healthy and postcolitic), and rectal nociception was assessed by measuring the behavioral response during CRD. Healthy rats were administered with sodium hydrogen sulfide (NaHS) (as a source of H(2)S), L-cysteine, or vehicle. In a second model, we investigated nociception to CRD in rats recovering from a chemically induced acute colitis. We found that CBS and CSE are expressed in the colon and spinal cord. Treating rats with NaHS resulted in a dose-dependent attenuation of CRD-induced nociception with the maximal effect at 60 micromol/kg (p < 0.05). Administration of L-cysteine, a CSE/CBS substrate, reduced rectal sensitivity to CRD (p < 0.05). NaHS-induced antinociception was reversed by glibenclamide, a ATP-sensitive K(+) (K(ATP)) channel inhibitor, and N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME), a nitric-oxide (NO) synthase inhibitor. The antinociceptive effect of NaHS was maintained during the resolution of colon inflammation induced by intrarectal administration of a chemical irritant. In summary, these data show that H(2)S inhibits nociception induced by CRD in both healthy and postcolitic rats. This effect is mediated by K(ATP) channels and NO. H(2)S-releasing drugs might be beneficial in treating painful intestinal disorders. PMID:16192316

  15. Hydrogenation reactions of ethylene on neutral vanadium sulfide clusters: experimental and theoretical studies.

    PubMed

    Yin, Shi; Xie, Yan; Bernstein, Elliot R

    2011-09-22

    The reactions of C(2)H(4) with H(2) on neutral vanadium sulfide clusters in a fast flow reactor are investigated by time-of-flight mass spectrometry employing 118 nm (10.5 eV) single photon ionization. The experimental products of these reactions are V(m)S(n)C(2)H(x) (m=1, n=1-3; m=2, n=1-5, and x=4-6). Observation of these products indicates that these V(m)S(n) clusters have high catalytic activity for hydrogenation reactions of C(2)H(4). Density functional theory calculations at the BPW91/TZVP level are carried out to explore the geometric and electronic structures of the V(m)S(n) clusters and to determine reaction intermediates and transition states, as well as reaction mechanisms. All reactions are estimated as overall barrierless or with only a small barrier (0.1 eV), and are thermodynamically favorable processes at room temperature. The ethylene molecule is predicted to connect with active V atoms through its ?-orbital or form a ?-bond with active V atoms of catalytic V(m)S(n) clusters. The S atoms bonding with active V atoms play an important role in the dissociation of the H(2) molecule; H atoms transfer to the C(2)H(4) (one after another) following breaking of the H-H bond. A catalytic cycle for C(2)H(4) hydrogenation reactions on a vanadium sulfide catalyst surface is suggested based on our experimental and theoretical investigations. PMID:21838236

  16. Design of a sorbent to enhance reactive adsorption of hydrogen sulfide.

    PubMed

    Wang, Long-Jiang; Fan, Hui-Ling; Shangguan, Ju; Croiset, Eric; Chen, Zhongwei; Wang, Hui; Mi, Jie

    2014-12-10

    A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature. PMID:25382853

  17. In vitro-controlled release delivery system for hydrogen sulfide donor.

    PubMed

    Ali, Hatim; Opere, Catherine; Singh, Somnath

    2014-08-01

    Hydrogen sulfide (H2S) is having many potential pharmacological and physiological actions which reported that therapeutically useful concentration is low (100-160?M) and a higher concentration could be toxic. Most of its donors produce it on coming into contact with water. All of these problems could be solved by a controlled-release delivery system which does not utilize water in any of its development steps. Therefore, 12 sustained release formulations were prepared by dissolving sodium hydrogen sulfide (NaHS)-a model H2S donor-in polymer solutions, prepared by dissolving polymers (consisted of either polylactide (PLA) or polylactide co-glycolide (PLGA), containing free carboxylic acid or capped allyl ester end group) in a mixture of benzyl benzoate (BB) and benzyl alcohol (BA). The formulation was injected in simulated tear fluid (STF) from which samples were withdrawn at specified times and assayed for NaHS content. We found decrease in burst and overall release with increase in polymer concentration from 10 to 20% w/v. The formulations containing free end group showed significant (p?

  18. Role of Hydrogen Sulfide in Early Blood-Brain Barrier Disruption following Transient Focal Cerebral Ischemia

    PubMed Central

    Jiang, Zheng; Li, Chun; Manuel, Morganne L.; Yuan, Shuai; Kevil, Christopher G.; McCarter, Kimberly D.; Lu, Wei; Sun, Hong

    2015-01-01

    We determined the role of endogenous hydrogen sulfide (H₂S) in cerebral vasodilation/hyperemia and early BBB disruption following ischemic stroke. A cranial window was prepared over the left frontal, parietal and temporal cortex in mice. Transient focal cerebral Ischemia was induced by directly ligating the middle cerebral artery (MCA) for two hours. Regional vascular response and cerebral blood flow (CBF) during ischemia and reperfusion were measured in real time. Early BBB disruption was assessed by Evans Blue (EB) and sodium fluorescein (Na-F) extravasation at 3 hours of reperfusion. Topical treatment with DL-propargylglycine (PAG, an inhibitor for cystathionine γ-lyase (CSE)) and aspartate (ASP, inhibitor for cysteine aminotransferase/3-mercaptopyruvate sulfurtransferase (CAT/3-MST)), but not O-(Carboxymethyl)hydroxylamine hemihydrochloride (CHH, an inhibitor for cystathionine β-synthase (CBS)), abolished postischemic cerebral vasodilation/hyperemia and prevented EB and Na-F extravasation. CSE knockout (CSE-/-) reduced postischemic cerebral vasodilation/hyperemia but only inhibited Na-F extravasation. An upregulated CBS was found in cerebral cortex of CSE-/- mice. Topical treatment with CHH didn’t further alter postischemic cerebral vasodilation/hyperemia, but prevented EB extravasation in CSE-/- mice. In addition, L-cysteine-induced hydrogen sulfide (H2S) production similarly increased in ischemic side cerebral cortex of control and CSE-/- mice. Our findings suggest that endogenous production of H2S by CSE and CAT/3-MST during reperfusion may be involved in postischemic cerebral vasodilation/hyperemia and play an important role in early BBB disruption following transient focal cerebral ischemia. PMID:25695633

  19. Hydrogen sulfide causes vanilloid receptor 1-mediated neurogenic inflammation in the airways

    PubMed Central

    Trevisani, Marcello; Patacchini, Riccardo; Nicoletti, Paola; Gatti, Raffaele; Gazzieri, David; Lissi, Nicola; Zagli, Giovanni; Creminon, Christophe; Geppetti, Pierangelo; Harrison, Selena

    2005-01-01

    Hydrogen sulfide (H2S) is described as a mediator of diverse biological effects, and is known to produce irritation and injury in the lung following inhalation. Recently, H2S has been found to cause contraction in the rat urinary bladder via a neurogenic mechanism. Here, we studied whether sodium hydrogen sulfide (NaHS), used as donor of H2S, produces responses mediated by sensory nerve activation in the guinea-pig airways. NaHS evoked an increase in neuropeptide release in the airways that was significantly attenuated by capsaicin desensitization and by the transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine. In addition, NaHS caused an atropine-resistant contraction of isolated airways, which was completely prevented by capsaicin desensitization. Furthermore, NaHS-induced contraction was reduced by TRPV1 antagonism (ruthenium red, capsazepine and SB366791), and was abolished by pretreatment with the combination of tachykinin NK1 (SR140333) and NK2 (SR48968) receptor antagonists. In anesthetized guinea-pigs, intratracheal instillation of NaHS increased the total lung resistance and airway plasma protein extravasation. These two effects were reduced by TRPV1 antagonism (capsazepine) and tachykinin receptors (SR140333 and SR48968) blockade. Our results provide the first pharmacological evidence that H2S provokes tachykinin-mediated neurogenic inflammatory responses in guinea-pig airways, and that this effect is mediated by stimulation of TRPV1 receptors on sensory nerves endings. This novel mechanism may contribute to the irritative action of H2S in the respiratory system. PMID:15937520

  20. Amorphous Molybdenum Sulfide on Graphene-Carbon Nanotube Hybrids as Highly Active Hydrogen Evolution Reaction Catalysts.

    PubMed

    Pham, Kien-Cuong; Chang, Yung-Huang; McPhail, David S; Mattevi, Cecilia; Wee, Andrew T S; Chua, Daniel H C

    2016-03-01

    In this study, we report on the deposition of amorphous molybdenum sulfide (MoSx, with x ≈ 3) on a high specific surface area conductive support of Graphene-Carbon Nanotube hybrids (GCNT) as the Hydrogen Evolution Reaction (HER) catalysts. We found that the high surface area GCNT electrode could support the deposition of MoSx at much higher loadings compared with simple porous carbon paper or flat graphite paper. The morphological study showed that MoSx was successfully deposited on and was in good contact with the GCNT support. Other physical characterization techniques suggested the amorphous nature of the deposited MoSx. With a typical catalyst loading of 3 mg cm(-2), an overpotential of 141 mV was required to obtain a current density of 10 mA cm(-2). A Tafel slope of 41 mV decade(-1) was demonstrated. Both measures placed the MoSx-deposited GCNT electrode among the best performing molybdenum sulfide-based HER catalysts reported to date. The electrode showed a good stability with only a 25 mV increase in overpotential required for a current density of 10 mA cm(-2), after undergoing 500 potential sweeps with vigorous bubbling present. The current density obtained at -0.5 V vs SHE (Standard Hydrogen Electrode potential) decreased less than 10% after the stability test. The deposition of MoSx on high specific surface area conductive electrodes demonstrated to be an efficient method to maximize the catalytic performance toward HER. PMID:26864503

  1. Methane, Carbon Dioxide, and Hydrogen Sulfide Production from the Terminal Methiol Group of Methionine by Anaerobic Lake Sediments

    PubMed Central

    Zinder, S. H.; Brock, T. D.

    1978-01-01

    A significant portion of the sulfide in lake sediments may be derived from sulfur-containing amino acids. Methionine degradation in Lake Mendota (Wisconsin) sediments was studied with gas chromatographic and radiotracer techniques. Temperature optimum and inhibitor studies showed that this process was biological. Methane thiol and dimethyl sulfide were produced in sediments when 1-?mol/ml unlabeled methionine was added. When chloroform (an inhibitor of one-carbon metabolism) was added to the sediments, methane thiol, carbon disulfide, and n-propane thiol were produced, even when no methionine was added. When 35S-labeled methionine was added to the sediments in tracer quantities (1.75 nmol/ml), labeled hydrogen sulfide was produced, and a roughly equal amount of label was incorporated into insoluble material. Methane and carbon dioxide were produced from [methyl-14C]methionine. Evidence is given favoring methane thiol as an intermediate in the formation of methane, carbon dioxide, and hydrogen sulfide from the terminal methiol group of methionine. Methionine may be an important source of sulfide in lake sediments. PMID:16345275

  2. Assessment of ruminal hydrogen sulfide or urine thiosulfate as diagnostic tools for sulfur induced polioencephalomalacia in cattle.

    PubMed

    Drewnoski, Mary E; Ensley, Steve M; Beitz, Don C; Schoonmaker, Jon P; Loy, Dan D; Imerman, Paula M; Rathje, John A; Hansen, Stephanie L

    2012-07-01

    To determine if ruminal hydrogen sulfide, urine thiosulfate, or blood sulfhemoglobin could be used as diagnostic indicators for sulfur-induced polioencephalomalacia, 16 steers (8 cannulated, 368 ± 12 kg; 8 unmodified, 388 ± 10 kg; mean ± standard error) were fed 1 of 2 dietary treatments. Diets consisted of a low sulfate (0.24% S; control) wheat midd-based pellet or the control pellet with sodium sulfate added to achieve a high-sulfate (0.68% S) pellet. As designed, intake did not differ (P = 0.80) between treatments. At 8 hr postfeeding, ruminal hydrogen sulfide was not affected by cannulation (P = 0.35) but was greater (P < 0.01) in high S (6,005 ± 475 mg/l) than control (1,639 ± 472 mg/l) steers. Time of day of sampling affected (P = 0.01) ruminal hydrogen sulfide, with peak concentrations occurring 4-12 hr after feeding. Urine was collected prefeeding (AM) and 7-9 hr postfeeding (PM). Urine thiosulfate concentrations of high S steers sampled in the PM were greater (P > 0.01) than in the AM. However, there was no difference due to time of sampling for control. In both the AM and PM, urine thiosulfate concentrations of high S were greater (P > 0.01) than control. Although hydrogen sulfide and thiosulfate were elevated by increased dietary S intake, a concentration at which polioencephalomalacia is likely to occur could not be determined. Sampling urine for thiosulfate or rumen gas for hydrogen sulfide of nonsymptomatic pen mates 4-8 hr after feeding may be useful to assess sulfur exposure and differentiate between causes of polioencephalomalacia. PMID:22643342

  3. Assessment of ruminal hydrogen sulfide or urine thiosulfate as diagnostic tools for sulfur induced polioencephalomalacia in cattle.

    TOXLINE Toxicology Bibliographic Information

    Drewnoski ME; Ensley SM; Beitz DC; Schoonmaker JP; Loy DD; Imerman PM; Rathje JA; Hansen SL

    2012-07-01

    To determine if ruminal hydrogen sulfide, urine thiosulfate, or blood sulfhemoglobin could be used as diagnostic indicators for sulfur-induced polioencephalomalacia, 16 steers (8 cannulated, 368 ± 12 kg; 8 unmodified, 388 ± 10 kg; mean ± standard error) were fed 1 of 2 dietary treatments. Diets consisted of a low sulfate (0.24% S; control) wheat midd-based pellet or the control pellet with sodium sulfate added to achieve a high-sulfate (0.68% S) pellet. As designed, intake did not differ (P = 0.80) between treatments. At 8 hr postfeeding, ruminal hydrogen sulfide was not affected by cannulation (P = 0.35) but was greater (P < 0.01) in high S (6,005 ± 475 mg/l) than control (1,639 ± 472 mg/l) steers. Time of day of sampling affected (P = 0.01) ruminal hydrogen sulfide, with peak concentrations occurring 4-12 hr after feeding. Urine was collected prefeeding (AM) and 7-9 hr postfeeding (PM). Urine thiosulfate concentrations of high S steers sampled in the PM were greater (P > 0.01) than in the AM. However, there was no difference due to time of sampling for control. In both the AM and PM, urine thiosulfate concentrations of high S were greater (P > 0.01) than control. Although hydrogen sulfide and thiosulfate were elevated by increased dietary S intake, a concentration at which polioencephalomalacia is likely to occur could not be determined. Sampling urine for thiosulfate or rumen gas for hydrogen sulfide of nonsymptomatic pen mates 4-8 hr after feeding may be useful to assess sulfur exposure and differentiate between causes of polioencephalomalacia.

  4. Removal of hydrogen sulfide from hot fuel gas using an electrochemical membrane system

    NASA Astrophysics Data System (ADS)

    Burke, Adrian Alan

    Sulfur is a natural contaminant in nearly all fossil fuel supplies. When a fuel stream is gasified or reformed, the sulfur manifests itself in the form of hydrogen sulfide, H2S. Extraordinary effort is put forth to remove H2S to at least ppm levels before the fuel can be used for power generation. To compete with current methods, an electrochemical membrane system (EMS) is now being studied to remove H2S in one step at high temperature. This process offers continuous H2S removal at an estimated operating cost of $0.32/kg H2S removed and a capital cost that is roughly half that of a Claus plant with tail-gas clean-up. Other advantages are the considerable savings in energy and space compared to current methods. A bench scale set-up was constructed to test the cell performance at 600-700°C and 1 atm. The typical fuel stream inlet proportions were 34% CO, 22% CO2, 35% H2, 8% H2O, and 450-2000 ppm H2S. The fundamental transport restrictions for sulfur species in an electrochemical cell were examined. Temperature and membrane thickness were varied to examine how these parameters affect the maximum flux of H 2S removal. It was found that higher temperature allows more sulfide species to enter the electrolyte, thus increasing the sulfide flux across the membrane and raising the maximum flux of H2S removal. Also, membrane thickness was found to be a critical parameter in cell design. A thinner membrane decreases the distance that sulfide ions must travel to be oxidized at the anode. These results identify sulfide diffusion across the membrane as the rate-limiting step in H2S removal. The maximum H2S removal flux of 1.1 x 10-6 gmol H2S min-1 cm-2 (or 3.5 mA cm-2) was obtained at 650°C, with a membrane that was 0.9 mm thick, 36% porous, and had an estimated tortuosity of 3.6. Another focus of this thesis was to examine the stability of cathode materials in full cell trials. A major hurdle that remains in process scale-up is cathode selection, as the lifetime of the cell will depend heavily on the lifetime of the cathode material, which is exposed to very sour gas. Materials that showed success in the past (i.e cobalt sulfides and Y0.9Ca 0.1FeO3) were examined but were seen to have limitations in operating environment and temperature. Therefore, other novel metal oxide compounds were studied to find possible candidates for full cell trials. Gd2TiMoO7 and La0.7Sr0.3VO 3 were the compounds that retained their structure best even when exposed to high H2S, CO2, and H2O concentrations. They also showed no sign of melting at operating temperatures. But Gd 2TiMoO7 was seen to have better stability with electrolyte present, whereas La0.7Sr0.3VO3 was seen to have better stability in the pure sour gas stream without electrolyte present. A layered electrode that could help preserve a stable environment for each of these compounds should be explored in future research.

  5. Liquid hydrogen densitometer utilizes open-ended microwave cavity

    NASA Technical Reports Server (NTRS)

    Smetana, J.; Wenger, N. C.

    1967-01-01

    Open-ended microwave cavity directly measures the density of flowing liquid, gaseous, or two-phase hydrogen. Its operation is based on derived relations between the cavity resonant frequency and the dielectric constant and density of hydrogen.

  6. Kinetics of hydrolysis and oxidation of carbon disulfide by hydrogen peroxide in alkaline medium and application to carbonyl sulfide

    SciTech Connect

    Adewuyi, Y.G.; Carmichael, G.R.

    1987-02-01

    Kinetic studies of the oxidation of carbon disulfide by hydrogen peroxide in alkaline medium were made spectrophotometrically. The reaction of CS/sub 2/ with OH/sup -/ ion was found to be rate controlling and proceeded by the formation of a dithiocarbonate complex. The major reaction product was sulfate with sulfur occurring as colloidal suspensions only at pH values less than 8. The formation of sulfate increased exponentially with time and was also found to be dependent on the rate of hydrolysis of CS/sub 2/. In addition, the production of sulfate showed large induction periods, suggesting either a complex mechanism or formation by secondary reactions. The results obtained for carbon disulfide were extended to carbonyl sulfide (OCS) oxidation in alkaline solutions. The removal of OCS (acid gas) from mixtures of gases by alkaline liquid absorbents (e.g. NaOH) and oxidation of subsequent solutions to sulfate is an important industrial practice. 42 references, 14 figures, 2 tables.

  7. Hydrogen sulfide oxidation is coupled to oxidative phosphorylation in mitochondria of Solemya reidi

    SciTech Connect

    Powell, M.A.; Somero, G.N.

    1986-08-01

    Solemya reidi, a gutless clam found in sulfide-rich habitats, contains within its gills bacterial symbionts thought to oxidize sulfur compounds and provide a reduced carbon food source to the clam. However, the initial step or steps in sulfide oxidation occur in the animal tissue, and mitochondria isolated from both gill and symbiont-free foot tissue of the clam coupled the oxidation of sulfide to oxidative phosphorylation (adenosine triphosphate (ATP) synthesis). The ability of Solemya reidi to exploit directly the energy in sulfide for ATP synthesis is unprecedented, and suggests that sulfide-habitat animals that lack bacterial symbionts may also use sulfide as an inorganic energy source.

  8. Effective Hydrogen Generation from the Hydrogen Sulfide Solution by using Stratified Type Photocatalyst

    SciTech Connect

    Takahashi, H.; Yokoyama, S.; Baba, Y.; Hayashi, T.; Tohji, K.

    2008-02-25

    Stratified type photocatalyst with the extremely higher photocatalytic activities can be synthesized by using the chemical reaction between the Na{sub 2}S solution and Cd(OH){sub 2} precursors. This type of photocatalyst has the specific morphology which constructed by the nano-sized and capsule like formed structure, and the metal concentration was gradually changed in its wall. The 'charge gradient' was formed at the metal sulfide and oxide/hydroxide junction in the wall, which favored for the separation of the photo excited electron-hole pair. Consequently, stratified type photocatalyst shows the high catalytic activity than the usual nano CdS particles. By the addition of sulfur compound into the bio reactor contained the sulfur reducing bacteria, the H{sub 2}S gas concentration can increased to about 1000 times enlarge than the usual condition. Therefore, we can conclude that the enhancement of the H{sub 2}S gas evolved from the bio reactor was successfully achievement, and we don't need to afraid the shortage risk of H{sub 2}S supply. These H{sub 2}S gas concentration can enlarged to 80% by using A type zeorite. Especially, Ca-A type zeorite is considered as the suitable material.

  9. Theoretical analysis for the heterogeneous decomposition of hydrogen sulfide to hydrogen on an iron-metallic plate in a laminar stagnation-point flow

    NASA Astrophysics Data System (ADS)

    Martnez, J. C.; Mndez, F.; Trevio, C.

    2006-12-01

    In this work, we have theoretically analyzed the conversion process of hydrogen sulfide, H 2S, to atomic hydrogen, H 0, in a planar stagnation-point flow over an iron-metallic surface. We assume that a binary mixture of hydrogen sulfide and methane composes the laminar stagnation flow. In order to characterize this complex phenomenon with very specific chemical activities on the surface of the metallic plate, we propose a heterogeneous reaction scheme based on four reactions: two electrochemical, one adsorption and an additional exothermic reaction needed to complete the direct conversion of hydrogen sulfide to hydrogen on the surface of the iron. The nondimensional governing equations, which include the mass species and momentum conservation of the mixture and the molecular diffusion of hydrogen into the iron plate, are numerically solved by conventional finite-difference methods. The numerical results show the critical conditions of the H 2S decomposition as functions of the involved nondimensional parameters of the present model. In particular, we show parametrically the influence that has the initial concentration of H 2S on the surface coverage of the chemical products HS - H + and H 0 derived from the chemical and electrochemical reactions.

  10. Vapor-liquid equilibria for the systems difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride

    SciTech Connect

    Kang, Y.W.

    1998-01-01

    Isothermal vapor-liquid equilibria for difluoromethane + hydrogen fluoride, dichlorodifluoromethane + hydrogen fluoride, and chlorine + hydrogen fluoride have been measured. The experimental data for the binary systems are correlated with the NRTL equation with the vapor-phase association model for the mixtures containing hydrogen fluoride, and the relevant parameters are presented. The binary system difluoromethane + hydrogen fluoride forms a homogeneous liquid phase, and the others form minimum boiling heterogeneous azeotropes at the experimental conditions.

  11. Density functional theory studies of the adsorption of hydrogen sulfide on aluminum doped silicane.

    PubMed

    Snchez-Ochoa, Francisco; Guerrero-Snchez, Jonathan; Canto, Gabriel I; Cocoletzi, Gregorio H; Takeuchi, Noboru

    2013-08-01

    First principles total energy calculations have been performed to study the hydrogen sulfide (H2S) adsorption on silicane, an unusual one monolayer of Si(111) surface hydrogenated on both sides. The H2S adsorption may take place in dissociative or non-dissociative forms. Silicane has been considered as: (A) non-doped with a hydrogen vacancy, and doped in two main configurations; (B) with an aluminum replacing a hydrogen atom and (C-n; n?=?1, 2, 3) with an aluminum replacing a silicon atom at a lattice site. In addition, three supercells; 4x4, 3x3 and 2x2 have been explored for both non-doped and doped silicane. The non-dissociative adsorption takes place in geometries (A), (C-1), (C-2) and (C-3) while the dissociative in (B). Adsorption energies of the dissociative case are larger than those corresponding to the non-dissociated cases. In the dissociative adsorption, the molecule is fragmented in a HS structure and a H atom which are bonded to the aluminum to form a H-S-Al-H structure. The presence of the doping produces some electronic changes as the periodicity varies. Calculations of the total density of states (DOS) indicate that in most cases the energy gap decreases as the periodicity changes from 4x4 to 2x2. The features of the total DOS are explained in terms of the partial DOS. The reported charge density plots explain quite well the chemisorptions and physisorptions of the molecule on silicane in agreement with adsorption energies. PMID:23695768

  12. Influence of support on the performance of molybdenum sulfide catalysts used to hydrotreat coal liquids

    SciTech Connect

    McCormick, R.L.

    1988-01-01

    Supports for molybdenum sulfide hydrotreating catalysts included silica, silica-magnesia, titania, chromia-alumina, activated carbon and nitrided activated carbon. The alumina supported Amocat 1A and Amocat 1C as well as the silica-alumina supported, Harshaw CoMo-0402 were also studied. Catalysts were characterized by BET surface area, mercury porosimetry and x-ray powder diffraction. Acidity was measured by the temperature programmed desorption of tert-butyl amine. Initial activity screening studies were conducted in a stirred autoclave batch reactor to determine appropriate metals loadings for the various supports. Initially active catalysts were then tested in a bench scale, trickle bed reactor to determine activity maintenance, coking tendency and selectivity at lined out conditions. Selectivities for hydrodenitrogenation and for the production of hydrogen donor molecules were of interest. The donatable hydrogen content of the produce was determined by {sup 1}H and {sup 13}C NMR spectroscopy. The results indicated a strong correlation between lined out hydrogenation activity and the volume in 60-200 {angstrom} diameter pores. A second correlation was observed between HDN activity and acid site density, indicating the importance of acid sites in denitrogenation. Low acidity catalysts appeared to produce a greater hydrogen donor content in the product oil than did high acidity catalysts but the results were not conclusive. The results also suggest that Bronsted acid sites can markedly reduce coking tendency but that in general, coke formation is related in a complex way to the acid/base chemistry of the surface.

  13. Operational overview of the NASA GTE/CITE 3 airborne instrument intercomparisons for sulfur dioxide, hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, and carbon disulfide

    NASA Technical Reports Server (NTRS)

    Hoell, James M., Jr.; Davis, Douglas D.; Gregory, Gerald L.; Mcneal, Robert J.; Bendura, Richard J.; Drewry, Joseph W.; Barrick, John D.; Kirchhoff, Volker W. J. H.; Motta, Adauto G.; Navarro, Roger L.

    1993-01-01

    This paper reports the overall experimental design and gives a brief overview of results from the third airborne Chemical Instrumentation Test and Evaluation (CITE 3) mission conducted as part of the National Aeronautics and Space Administration's Global Tropospheric Experiment. The primary objective of CITE 3 was to evaluate the capability of instrumentation for airborne measurements of ambient concentrations of SO2, H2S, CS, dimethyl sulfide, and carbonyl sulfide. Ancillary measurements augmented the intercomparison data in order to address the secondary objective of CITE 3 which was to address specific issues related to the budget and photochemistry of tropospheric sulfur species. The CITE 3 mission was conducted on NASA's Wallops Flight Center Electra aircraft and included a ground-based intercomparison of sulfur standards and intercomparison/sulfur science flights conducted from the NASA Wallops Flight Facility, Wallops Island, Virginia, followed by flights from Natal, Brazil. Including the transit flights, CITE 3 included 16 flights encompassing approximately 96 flight hours.

  14. A storage tank for vehicular storage of liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Williams, L. O.; Spond, D. E.

    1980-04-01

    This article outlines a concept for a new method of fabricating cryogenic liquid hydrogen storage tanks with emphasis on the application of liquid hydrogen as an automotive fuel. It includes a recapitulation of the properties of hydrogen and gasoline for reference, a discussion of automotive fuel utilisation rates, a thermal analysis of the liquid hydrogen boil-off rate for a reference storage container and the new concept tank. In addition, an analysis of the tank concept and its method of assembly line fabrication are provided. The conclusions reached are that this fabrication concept would provide a liquid hydrogen storage tank of improved thermal performance, that the tank could be potentially less expensive to build than current technology tanks, and that the tank would be suitable for automotive containment of liquid hydrogen.

  15. Hydrogen sulfide prolongs postharvest shelf life of strawberry and plays an antioxidative role in fruits.

    PubMed

    Hu, Lan-Ying; Hu, Shu-Li; Wu, Jun; Li, Yan-Hong; Zheng, Ji-Lian; Wei, Zhao-Jun; Liu, Jian; Wang, Hui-Li; Liu, Yong-Sheng; Zhang, Hua

    2012-09-01

    Accumulating evidence shows that hydrogen sulfide (H(2)S) plays various physiological roles in plants, such as seed germination, root organogenesis, abiotic stress tolerance, and senescence of cut flowers. However, whether H(2)S participates in the regulation of ripening and senescence in postharvest fruits remains unknown. In the present study, the effect of H(2)S on postharvest shelf life and antioxidant metabolism in strawberry fruits was investigated. Fumigation with H(2)S gas released from the H(2)S donor NaHS prolonged postharvest shelf life of strawberry fruits in a dose-dependent manner. Strawberry fruits fumigated with various concentrations of H(2)S sustained significantly lower rot index, higher fruit firmness, and kept lower respiration intensity and polygalacturonase activities than controls. Further investigation showed that H(2)S treatment maintained higher activities of catalase, guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase and lower activities of lipoxygenase relative to untreated controls. H(2)S also reduced malondialdehyde, hydrogen peroxide, and superoxide anion to levels below control fruits during storage. Moreover, H(2)S treatment maintained higher contents of reducing sugars, soluble proteins, free amino acid, and endogenous H(2)S in fruits. We interpret these data as indicating that H(2)S plays an antioxidative role in prolonging postharvest shelf life of strawberry fruits. PMID:22871304

  16. Kinetics and mechanisms of iron sulfide reductions in hydrogen and in carbon monoxide

    USGS Publications Warehouse

    Wiltowski, T.; Hinckley, C.C.; Smith, Gerard V.; Nishizawa, T.; Saporoschenko, Mykola; Shiley, R.H.; Webster, J.R.

    1987-01-01

    The reduction of iron sulfides by hydrogen and by carbon monoxide has been studied using plug flow and thermogravimetric methods. The reactions were studied in the 523-723??K temperature range and were found to be first-order processes. Plug flow studies were used to correlate reaction rates between pyrite and the gases as a function of the surface area of the pyrite. The rate of H2S formation increases with the surface area of the pyrite sample. The results of thermogravimetric experiments indicate that the reactions consist of several steps. Rate constants for the pyrite reduction by H2 and by CO were obtained. The activation energies increased with degree of reduction. Values of Ea were 113.2 (step I) and 122.5 kJ/mole (step II) for pyrite reduction with CO and 99.4 (step I), 122.4 (step II), 125.2 (step III), and 142.6 kJ/mole (step IV) for pyrite reduction with hydrogen. ?? 1987.

  17. Factors affecting activated carbon-based catalysts for selective hydrogen sulfide oxidation

    SciTech Connect

    Li, Huixing; Monnell, J.D.; Alvin, M.A.; Vidic, R.D.

    2008-09-01

    The primary product of coal gasification processes is synthesis gas (syngas), a mixture of CO, H2, CO2, H2O and a number of minor components. Among the most significant minor components in syngas is hydrogen sulfide (H2S). In addition to its adverse environmental impact, H2S poisons the catalysts and hydrogen purification membranes, and causes severe corrosion in gas turbines. Technologies that can remove H2S from syngas and related process streams are, therefore, of considerable practical interest. To meet this need, we work towards understanding the mechanism by which prospective H2S catalysts perform in simulated fuel gas conditions. Specifically, we show that for low-temperature gas clean-up (~1408C) using activated carbon fibers and water plays a significant role in H2S binding and helps to prolong the lifetime of the material. Basic surface functional groups were found to be imperative for significant conversion of H2S to daughter compounds, whereas metal oxides (La and Ce) did little to enhance this catalysis. We show that although thermal regeneration of the material is possible, the regenerated material has a substantially lower catalytic and sorption capacity.

  18. Regulation of hydrogen sulfide liberation in wine-producing Saccharomyces cerevisiae strains by assimilable nitrogen.

    PubMed

    Jiranek, V; Langridge, P; Henschke, P A

    1995-02-01

    Saccharomyces cerevisiae wine-producing yeast cultures grown under model winemaking conditions could be induced to liberate hydrogen sulfide (H2S) by starvation for assimilable nitrogen. The amount of H2S produced was dependent on the yeast strain, the sulfur precursor compound, the culture growth rate, and the activity of the sulfite reductase enzyme (EC 1.8.1.2) immediately before nitrogen depletion. Increased H2S formation relative to its utilization by metabolism was not a consequence of a de novo synthesis of sulfite reductase. The greatest amount of H2S was produced when nitrogen became depleted during the exponential phase of growth or during growth on amino acids capable of supporting short doubling times. Both sulfate and sulfite were able to act as substrates for the generation of H2S in the absence of assimilable nitrogen; however, sulfate reduction was tightly regulated, leading to limited H2S liberation, whereas sulfite reduction appeared to be uncontrolled. In addition to ammonium, most amino acids were able to suppress the liberation of excess H2S when added as sole sources of nitrogen, particularly for one of the strains studied. Cysteine was the most notable exception, inducing the liberation of H2S at levels exceeding that of the nitrogen-depleted control. Threonine and proline also proved to be poor substitutes for ammonium. These data suggest that any compound that can efficiently generate sulfide-binding nitrogenous precursors of organic sulfur compounds will prevent the liberation of excess H2S. PMID:7574581

  19. Regulation of mitochondrial bioenergetic function by hydrogen sulfide. Part I. Biochemical and physiological mechanisms

    PubMed Central

    Szabo, Csaba; Ransy, Céline; Módis, Katalin; Andriamihaja, Mireille; Murghes, Baptiste; Coletta, Ciro; Olah, Gabor; Yanagi, Kazunori; Bouillaud, Frédéric

    2014-01-01

    Until recently, hydrogen sulfide (H2S) was exclusively viewed a toxic gas and an environmental hazard, with its toxicity primarily attributed to the inhibition of mitochondrial Complex IV, resulting in a shutdown of mitochondrial electron transport and cellular ATP generation. Work over the last decade established multiple biological regulatory roles of H2S, as an endogenous gaseous transmitter. H2S is produced by cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). In striking contrast to its inhibitory effect on Complex IV, recent studies showed that at lower concentrations, H2S serves as a stimulator of electron transport in mammalian cells, by acting as a mitochondrial electron donor. Endogenous H2S, produced by mitochondrially localized 3-MST, supports basal, physiological cellular bioenergetic functions; the activity of this metabolic support declines with physiological aging. In specialized conditions (calcium overload in vascular smooth muscle, colon cancer cells), CSE and CBS can also associate with the mitochondria; H2S produced by these enzymes, serves as an endogenous stimulator of cellular bioenergetics. The current article overviews the biochemical mechanisms underlying the stimulatory and inhibitory effects of H2S on mitochondrial function and cellular bioenergetics and discusses the implication of these processes for normal cellular physiology. The relevance of H2S biology is also discussed in the context of colonic epithelial cell physiology: colonocytes are exposed to high levels of sulfide produced by enteric bacteria, and serve as a metabolic barrier to limit their entry into the mammalian host, while, at the same time, utilizing it as a metabolic ‘fuel’. Linked Articles This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8 PMID:23991830

  20. Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Guibling Zhao; Ji-Jun Zhang; Sanil John

    2005-10-01

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. A pulsed corona discharge (PCD) reactor has been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. A nonthermal plasma cannot be produced in pure H{sub 2}S with our reactor geometry, even at discharge voltages of up to 30 kV, because of the high dielectric strength of pure H{sub 2}S ({approx}2.9 times higher than air). Therefore, H{sub 2}S was diluted in another gas with lower breakdown voltage (or dielectric strength). Breakdown voltages of H{sub 2}S in four balance gases (Ar, He, N{sub 2} and H{sub 2}) have been measured at different H{sub 2}S concentrations and pressures. Breakdown voltages are proportional to the partial pressure of H{sub 2}S and the balance gas. H{sub 2}S conversion and the reaction energy efficiency depend on the balance gas and H{sub 2}S inlet concentrations. With increasing H{sub 2}S concentrations, H{sub 2}S conversion initially increases, reaches a maximum, and then decreases. H{sub 2}S conversion in atomic balance gases, such as Ar and He, is more efficient than that in diatomic balance gases, such as N{sub 2} and H{sub 2}. These observations can be explained by the proposed reaction mechanism of H{sub 2}S dissociation in different balance gases. The results show that nonthermal plasmas are effective for dissociating H{sub 2}S into hydrogen and sulfur.

  1. Phase- and morphology-controlled synthesis of cobalt sulfide nanocrystals and comparison of their catalytic activities for hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Pan, Yuan; Liu, Yunqi; Liu, Chenguang

    2015-12-01

    Colalt sulfide nanocrystals (NCs), including dandelion-like Co9S8 and sphere-like Co3S4, have been synthesized via a thermal decomposition approach using cobalt acetylacetonate as the cobalt source, 1-dodecanethiol as the sulfur source and oleic acid or oleylamine as the high boiling organic solvent. It is found that the molar ratio of the Co:S precursor and the species of solvent play an important role in the control of phase and morphology of cobalt sulfide nanostructures. The phase structure and morphology of the as-synthesized nickel sulfide NCs are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), energy dispersive spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption. Then we further compare the electrocatalytic activity and stability of as-synthesized cobalt sulfide NCs for hydrogen evolution reaction (HER). The results show that sphere-like Co3S4 exhibits better electrocatalytic activity than the dandelion-like Co9S8 NCs for HER, which can be attributed to the difference of phase structure and morphology. The sphere-like Co3S4 NCs have large surface area and high electrical conductivity, both are beneficial to enhance the catalytic activity. This study indicates that the crystalline phase structure and morphology of cobalt sulfide NCs are important for designing HER electrocatalysts with high efficiency and good stability.

  2. Ordered pairing in liquid metallic hydrogen

    NASA Technical Reports Server (NTRS)

    Carlsson, A. E.; Ashcroft, N. W.

    1983-01-01

    We study two possible types of pairing involving the protons of a proposed low-temperature liquid phase metallic hydrogen. Electron-proton pairing, which can result in an insulating phase, is investigated by using an approximate solution of an Eliashberg-type equation for the anomalous self-energy. A very low estimate of the transition temperature is obtained by including proton correlations in the effective interaction. For proton-proton pairing, we derive a new proton pair potential based on the Abrikosov wave function. This potential includes the electron-proton interaction to all orders and has a much larger well depth than is obtained with linear screening methods. This suggests the possibility of either a superfluid paired phase analogous to that in He-3, or alternatively a phase with true molecular pairing.

  3. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored within an intraline...

  4. 14 CFR 420.66 - Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored... Responsibilities of a Licensee § 420.66 Separation distance requirements for storage of hydrogen peroxide, hydrazine, and liquid hydrogen and any incompatible energetic liquids stored within an intraline...

  5. Aircraft-Fuel-Tank Design for Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Reynolds, T W

    1955-01-01

    Some of the considerations involved in the design of aircraft fuel tanks for liquid hydrogen are discussed herein. Several of the physical properties of metals and thermal insulators in the temperature range from ambient to liquid-hydrogen temperatures are assembled. Calculations based on these properties indicate that it is possible to build a large-size liquid-hydrogen fuel tank which (1) will weigh less then 15 percent of the fuel weight, (2) will have a hydrogen vaporization rate less than 30 percent of the cruise fuel-flow rate, and (3) can be held in a stand-by condition and readied for flight in a short time.

  6. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

    1985-01-01

    A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

  7. Sulfide chemiluminescence detection

    DOEpatents

    Spurlin, S.R.; Yeung, E.S.

    1985-11-26

    A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

  8. Refueling considerations for liquid-hydrogen fueled vehicles

    SciTech Connect

    Stewart, W.F.

    1984-01-01

    Liquid hydrogen is a possible fuel for transportation applications in the future. Such use of liquid hydrogen will require a refueling station analogous to today's service station for gasoline and diesel fuels. The cryogenic nature of liquid hydrogen and concerns for safety indicate the desirability of a refueling system that is automated as completely as possible and incorporates sufficient redundancy for safe and reliable operation. A refueling system designed on the basis of previous experience with liquid hydrogen transfer systems has been developed, and a preliminary system has been built and tested. A series of tests was conducted to determine the extent of the liquid hydrogen losses during a refueling operation and to determine optimum transfer procedures and conditions.

  9. Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)

    PubMed Central

    Sitdikova, Guzel F.; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M.; Hermann, Anton

    2014-01-01

    Introduction: Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. Aims: The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H2S on the channel as well as to recalculate and determine the H2S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions. Methods: Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H2S was measured with an anion selective electrode. Results: The concentration of H2S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H2S into account. The results indicate that from a concentration of 300 μM NaHS, only 11–13%, i.e., 34–41 μM is effective as H2S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H2S in ATP-containing solutions. PKA prevented the action of H2S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H2S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H2S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H2S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H2S was also observed in the presence of okadaic acid. Conclusions: Our results suggest that phosphorylation by PKG primes the channels for H2S activation and indicate that channel phosphorylation plays an important role in the response to H2S. PMID:25429270

  10. Hydrogen sulfide increases excitability through suppression of sustained potassium channel currents of rat trigeminal ganglion neurons

    PubMed Central

    2013-01-01

    Background Hydrogen sulfide (H2S), an endogenous gaseotransmitter/modulator, is becoming appreciated that it may be involved in a wide variety of processes including inflammation and nociception. However, the role and mechanism for H2S in nociceptive processing in trigeminal ganglion (TG) neuron remains unknown. The aim of this study is to investigate distribution of endogenous H2S synthesizing enzyme cystathionine-β-synthetase (CBS) expression and role of H2S on excitability and voltage-gated potassium channels of TG neurons. Methods Immunofluorescence studies were carried out to determine whether CBS was co-expressed in Kv1.1 or Kv1.4-positive TG neurons. Whole cell patch clamp recordings were employed on acutely isolated TG neurons from adult male Sprague Dawley rats (6–8 week old). von Frey filaments were used to examine the pain behavioral responses in rats following injection of sodium hydrosulfide. Results In rat TG, 77.3±6.6% neurons were immunoreactive for CBS, 85.1±3.8% for Kv1.1 and 97.8±1.1% for Kv1.4. Double staining showed that all CBS labeled cells were Kv1.1 and Kv1.4 positive, but only 92.2±6.1% of Kv1.1 and 78.2±9.9% of Kv1.4 positive cells contained CBS. Application of H2S donor NaHS (250 μM) led to a significant depolarization of resting membrane potential recorded from TG neurons. NaHS application also resulted in a dramatic reduction in rheobase, hyperpolarization of action potential threshold, and a significant increase in the number of action potentials evoked at 2X and 3X rheobase stimulation. Under voltage-clamp conditions, TG neurons exhibited transient A-type (IA) and sustained outward rectifier K+ currents (IK). Application of NaHS did suppress IK density while did not change IA density of TG neurons (n=6). Furthermore, NaHS, a donor of hydrogen sulfide, produced a significant reduction in escape threshold in a dose dependent manner. Conclusion These data suggest that endogenous H2S generating enzyme CBS was co-localized well with Kv1.1 and Kv1.4 in TG neurons and that H2S produces the mechanic pain and increases neuronal excitability, which might be largely mediated by suppressing IK density, thus identifying for the first time a specific molecular mechanism underlying pain and sensitization in TG. PMID:23413915

  11. Suicide Fads: Frequency and Characteristics of Hydrogen Sulfide Suicides in the United States

    PubMed Central

    Reedy, Sarah Jane D.; Schwartz, Michael D.; Morgan, Brent W.

    2011-01-01

    Objective: To assess the frequency of hydrogen sulfide (H2S) suicides and describe the characteristics of victims in the United States (U.S.) since the technique became common in Japan in 2007. Methods: To ascertain the frequency of intentional H2S related deaths in the U.S. prior to the start of the Japanese trend in 2007, we searched the multiple-cause-of-death data from the National Vital Statistics System. To collect as much information about the victims as possible, we sent an email to the National Association of Medical Examiners (NAME) listserv asking for their cooperation in identifying cases of H2S suicide. To identify cases that were not voluntarily reported by medical examiners but were reported by the media, we conducted Google searches using the search terms: “hydrogen sulfide suicide,” “H2S suicide,” “detergent suicide,” “chemical suicide,” and “suicide fad.” We obtained all available autopsy reports and abstracted information, including the site of the incident, the presence of a note warning others about the toxic gas and the demographic characteristics of the victims. We contacted medical examiners who potentially had custody of the cases that were identified through media reports and requested autopsies of these victims. When unable to obtain the autopsies, we gathered information from the media reports. Results: Forty-five deaths from H2S exposure occurred in the U.S. from 1999 to 2007, all unintentional. Responses from the NAME listserv yielded autopsy reports for 11 victims, and Google searches revealed an additional 19 H2S suicides in the U.S. since 2008. Overall (n=30), two cases were identified during 2008, 10 in 2009, and 18 in 2010. The majority of victims were white males, less than 30-years-old, left a warning note, and were found in cars. There were five reports of injuries to first responders, but no secondary fatalities. Conclusion: H2S suicides are increasing in the U.S., and their incidence is probably underestimated by public health officials and physicians. First responders are at risk when assessing these victims due to the severe toxicity of the gas. Emergency providers must be aware of H2S suicides to educate others and care for the rare survivor. PMID:21731786

  12. New spectrophotometric methods for the determinations of hydrogen sulfide present in the samples of lake water, industrial effluents, tender coconut, sugarcane juice and egg

    NASA Astrophysics Data System (ADS)

    Shyla, B.; Nagendrappa, G.

    2012-10-01

    The new methods are working on the principle that iron(III) is reduced to iron(II) by hydrogen sulfide, catechol and p-toluidine the system 1/hydrogen sulfide the system 2, in acidic medium followed by the reduced iron forming complex with 1,10-phenanthroline with λmax 510 nm. The other two methods are based on redox reactions between electrolytically generated manganese(III) sulfate taken in excess and hydrogen sulfide followed by the unreacted oxidant oxidizing diphenylamine λmax 570 the system 3/barium diphenylamine sulphonate λmax 540 nm, the system 4. The increase/decrease in the color intensity of the dye products of the systems 1 and 2 or 3 and 4 are proportional to the concentration of hydrogen sulfide with its quantification range 0.035-1.40 μg ml-1/0.14-1.40 μg ml-1.

  13. New spectrophotometric methods for the determinations of hydrogen sulfide present in the samples of lake water, industrial effluents, tender coconut, sugarcane juice and egg.

    PubMed

    Shyla, B; Nagendrappa, G

    2012-10-01

    The new methods are working on the principle that iron(III) is reduced to iron(II) by hydrogen sulfide, catechol and p-toluidine the system 1/hydrogen sulfide the system 2, in acidic medium followed by the reduced iron forming complex with 1,10-phenanthroline with ?(max) 510 nm. The other two methods are based on redox reactions between electrolytically generated manganese(III) sulfate taken in excess and hydrogen sulfide followed by the unreacted oxidant oxidizing diphenylamine ?(max) 570 the system 3/barium diphenylamine sulphonate ?(max) 540 nm, the system 4. The increase/decrease in the color intensity of the dye products of the systems 1 and 2 or 3 and 4 are proportional to the concentration of hydrogen sulfide with its quantification range 0.035-1.40 ?g ml(-1)/0.14-1.40 ?g ml(-1). PMID:22889607

  14. Novel Composite Hydrogen-Permeable Membranes for Non-Thermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Guibing Zhao; Sanil John

    2006-09-30

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Several pulsed corona discharge (PCD) reactors have been fabricated and used to dissociate H{sub 2}S into hydrogen and sulfur. Visual observation shows that the corona is not uniform throughout the reactor. The corona is stronger near the top of the reactor in argon, while nitrogen and mixtures of argon or nitrogen with H{sub 2}S produce stronger coronas near the bottom of the reactor. Both of these effects appear to be explainable base on the different electron collision interactions with monatomic versus polyatomic gases. A series of experiments varying reactor operating parameters, including discharge capacitance, pulse frequency, and discharge voltage were performed while maintaining constant power input to the reactor. At constant reactor power input, low capacitance, high pulse frequency, and high voltage operation appear to provide the highest conversion and the highest energy efficiency for H{sub 2}S decomposition. Reaction rates and energy efficiency per H{sub 2}S molecule increase with increasing flow rate, although overall H{sub 2}S conversion decreases at constant power input. Voltage and current waveform analysis is ongoing to determine the fundamental operating characteristics of the reactors. A metal infiltrated porous ceramic membrane was prepared using vanadium as the metal and an alumina tube. Experiments with this type of membrane are continuing, but the results thus far have been consistent with those obtained in previous project years: plasma driven permeation or superpermeability has not been observed. A new test cell specially designed to test the membranes has been constructed to provide basic science data on superpermeability.

  15. NOVEL COMPOSITE HYDROGEN-PERMEABLE MEMBRANES FOR NON-THERMAL PLASMA REACTORS FOR THE DECOMPOSITION OF HYDROGEN SULFIDE

    SciTech Connect

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Ji-Jun Zhang; Guibing Zhao; Robyn J. Alcanzare; Linna Wang; Ovid A. Plumb

    2004-07-01

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Experiments involving methane conversion reactions were conducted with a preliminary pulsed corona discharge reactor design in order to test and improve the reactor and membrane designs using a non-toxic reactant. This report details the direct methane conversion experiments to produce hydrogen, acetylene, and higher hydrocarbons utilizing a co-axial cylinder (CAC) corona discharge reactor, pulsed with a thyratron switch. The reactor was designed to accommodate relatively high flow rates (655 x 10{sup -6} m{sup 3}/s) representing a pilot scale easily converted to commercial scale. Parameters expected to influence methane conversion including pulse frequency, charge voltage, capacitance, residence time, and electrode material were investigated. Conversion, selectivity and energy consumption were measured or estimated. C{sub 2} and C{sub 3} hydrocarbon products were analyzed with a residual gas analyzer (RGA). In order to obtain quantitative results, the complex sample spectra were de-convoluted via a linear least squares method. Methane conversion as high as 51% was achieved. The products are typically 50%-60% acetylene, 20% propane, 10% ethane and ethylene, and 5% propylene. First Law thermodynamic energy efficiencies for the system (electrical and reactor) were estimated to range from 38% to 6%, with the highest efficiencies occurring at short residence time and low power input (low specific energy) where conversion is the lowest (less than 5%). The highest methane conversion of 51% occurred at a residence time of 18.8 s with a flow rate of 39.4 x 10{sup -6} m{sup 3}/s (5 ft{sup 3}/h) and a specific energy of 13,000 J/l using niobium and platinum coated stainless steel tubes as cathodes. Under these conditions, the First Law efficiency for the system was 8%. Under similar reaction conditions, methane conversions were {approx}50% higher with niobium and platinum coated stainless steel cathodes than with a stainless steel cathode.

  16. Source Of Hydrogen Sulfide To Sulfidic Spring And Watershed Ecosystems In Northern Sierra De Chiapas, Mexico Based On Sulfur And Carbon Isotopes

    NASA Astrophysics Data System (ADS)

    Rosales Lagarde, L.; Boston, P. J.; Campbell, A.

    2013-12-01

    At least four watersheds in northern Sierra de Chiapas, Mexico are fed by conspicuous karst sulfide-rich springs. The toxic hydrogen sulfide (H2S) in these springs nurtures rich ecosystems including especially adapted microorganisms, invertebrates and fish. Sulfur and carbon isotopic analysis of various chemical species in the spring water are integrated within their hydrogeologic context to evaluate the hydrogen sulfide source. Constraining the H2S origin can also increase the understanding of this compound effect in the quality of the nearby hydrocarbon reservoirs, and the extent to which its oxidation to sulfuric acid increases carbonate dissolution and steel corrosion in surface structures. The SO42-/H2S ratio in the spring water varies from 70,000 to 2 meq/L thus sulfate is the dominant species in the groundwater system. This sulfate is mainly produced from anhydrite dissolution based on its isotopic signature. The Δ SO42--H2S range of 16 spring water samples (30-50 ‰) is similar to the values determined by Goldhaber & Kaplan (1975) and Canfield (2001) for low rates of bacterial sulfate reduction suggesting that this is the most important mechanism producing H2S. Although the carbon isotopes do not constrain the nature of the organic matter participating in this reaction, this material likely comes from depth, perhaps as hydrocarbons, due to the apparent stability of the system. The organic matter availability and reactivity probably control the progress of sulfate reduction. The subsurface environments identified in the area also have different sulfur isotopic values. The heavier residual sulfate isotopic value in the Northern brackish springs (δ34S SO42- ≥ 18 ‰) compared to the Southern springs (δ34S SO42- ~18 ‰) suggests sulfate reduction is particularly enhanced in the former, probably by contribution of organic matter associated with oil produced water. In comparison, the composition of the Southern aquifer is mainly influenced by halite dissolution. Fresh water from the Local environment percolates into the Northern and the Southern environments. Mixing between these three aquifers may enhance bacterial sulfate reduction, thus increasing the H2S concentration in the sulfidic springs. The integration of the geochemical attributes and the aquatic communities at each watershed will produce a more comprehensive view of these spring ecosystems and their temporal and spatial evolution.

  17. Microbiological removal of hydrogen sulfide from biogas by means of a separate biofilter system: experience with technical operation.

    PubMed

    Schieder, D; Quicker, P; Schneider, R; Winter, H; Prechtl, S; Faulstich, M

    2003-01-01

    The "BIO-Sulfex" biofilter of ATZ-EVUS removes hydrogen sulfide from biogas in a biological way. Hydrogen sulfide causes massive problems during power generation from biogas in a power plant, e.g. corrosion of engines and heat exchangers, and thus causes frequent and therefore expensive engine oil changes. The BIO-Sulfex module is placed between the digester and the power-plant and warrants a cost-effective, reliable and fully biological desulfurization. In the cleaned gas concentrations of less than 100 ppm can be achieved. Power-plant manufacturers usually demand less than 500 or less than 200 ppm. At present, several plants with biogas flow rates between 20 and 350 m3/h are in operation. PMID:14531443

  18. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation

    PubMed Central

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A.; Milstein, David

    2015-01-01

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system. PMID:25882348

  19. Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study

    PubMed Central

    Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

    2014-01-01

    Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

  20. Genetic targets of hydrogen sulfide in ventilator-induced lung injury--a microarray study.

    PubMed

    Spassov, Sashko; Pfeifer, Dietmar; Strosing, Karl; Ryter, Stefan; Hummel, Matthias; Faller, Simone; Hoetzel, Alexander

    2014-01-01

    Recently, we have shown that inhalation of hydrogen sulfide (H2S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H2S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H2S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H2S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H2S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H2S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H2S. In conclusion, lung protection by H2S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H2S mediated protection. PMID:25025333

  1. Response of a ZnO single crystal rod-based chemical sensor for hydrogen sulfide.

    PubMed

    Park, N-K; Park, J Y; Lee, T J

    2014-08-01

    A zinc oxide single crystal rod was grown by a thermal evaporation method for application as a chemical gas-sensing material in this study. Zinc acetate (20 wt%) impregnated over activated carbon was used as the precursor for the epitaxial growth of ZnO single crystal rods. The response tests were carried out across a range of sensing temperatures (100, 150 and 200 C) and the hydrogen sulfide content (10.2-51.0 ppmv) was balanced with nitrogen gas. The response of the ZnO single crystal rods grown on the gas sensors varied with the H2S content and the sensing temperature. A high response for H2S was obtained at 150 and 200 C due to the high reactivity between H2S and ZnO at high temperature. Since H2S absorption rate and ZnS oxidation rate over ZnO single crystal rods at 100 C lower than that at 150 and 200 C, the changing rate of electric resistance decreased with the decrease of temperature. Meanwhile, a different response, which is the changing rate of electric resistance for H2S absorption and ZnS oxidation over ZnO single crystal rods at 100 C, was observed with changing amount of H2S in feed gas. Therefore, it was concluded that the ZnO single crystal rods based gas sensor is operated above 200 C for the shortly response time. PMID:25936113

  2. Highly sensitive hydrogen sulfide (H?S) gas sensors from viral-templated nanocrystalline gold nanowires.

    PubMed

    Moon, Chung Hee; Zhang, Miluo; Myung, Nosang V; Haberer, Elaine D

    2014-04-01

    A facile, site-specific viral-templated assembly method was used to fabricate sensitive hydrogen sulfide (H2S) gas sensors at room temperature. A gold-binding M13 bacteriophage served to organize gold nanoparticles into linear arrays which were used as seeds for subsequent nanowire formation through electroless deposition. Nanowire widths and densities within the sensors were modified by electroless deposition time and phage concentration, respectively, to tune device resistance. Chemiresistive H2S gas sensors with superior room temperature sensing performance were produced with sensitivity of 654%/ppm(v), theoretical lowest detection limit of 2 ppb(v), and 70% recovery within 9 min for 0.025 ppm(v). The role of the viral template and associated gold-binding peptide was elucidated by removing organics using a short O? plasma treatment followed by an ethanol dip. The template and gold-binding peptide were crucial to electrical and sensor performance. Without surface organics, the resistance fell by several orders of magnitude, the sensitivity dropped by more than a factor of 100 to 6%/ppm(v), the lower limit of detection increased, and no recovery was detected with dry air flow. Viral templates provide a novel, alternative fabrication route for highly sensitive, nanostructured H2S gas sensors. PMID:24598078

  3. Removal of hydrogen sulfide at ambient conditions on cadmium/GO-based composite adsorbents.

    PubMed

    Florent, Marc; Wallace, Rajiv; Bandosz, Teresa J

    2015-06-15

    Cadmium-based materials with various hydroxide to carbonate ratios and their composites with graphite oxide were synthesized by a fast and simple precipitation procedure and then used as H2S adsorbents at ambient conditions in the dark or upon a visible light exposure. The structural properties and chemical features of the adsorbents were analyzed before and after hydrogen sulfide adsorption. The results showed that the high ratio of hydroxide to carbonate led to an improved H2S adsorption capacity. In moist conditions cadmium hydroxide was the best adsorbent. Moreover, it showed photoactive properties. While the incorporation of a graphene-based phase slightly decreased the extent of the improvement in the H2S adsorption capacity in moist conditions caused by photoactivity, its presence in the composites enhanced the performance in dry conditions. This was linked to photoactivity of CdS that can split H2S resulting in the formation of water in the system. The graphene-based phase enhanced the electron transfer and delayed the recombination of photoinduced charges. Carbonate-based materials showed a very good adsorption capacity in dark conditions in the presence of moisture. Upon the light exposure, CdS likely photocatalyzes the reduction of carbonate ions to formates/formaldehydes. Their deposition on the surface limits the number of sites available to H2S adsorption. PMID:25792480

  4. Bacteria-derived hydrogen sulfide promotes IL-8 production from epithelial cells.

    PubMed

    Chen, Weilin; Kajiya, Mikihito; Giro, Gabriela; Ouhara, Kazuhisa; Mackler, Harrison E; Mawardi, Hani; Boisvert, Heike; Duncan, Margaret J; Sato, Kimihiro; Kawai, Toshihisa

    2010-01-01

    Hydrogen sulfide (H(2)S), a volatile sulfur compound, is implicated as a cause of inflammation, especially when it is produced by bacteria colonizing gastrointestinal organs. However, it is unclear if H(2)S produced by periodontal pathogens affects the inflammatory responses mediated by oral/gingival epithelial cells. Therefore, the aims of this study were (1) to compare the in vitro production of H(2)S among 14 strains of oral bacteria and (2) to evaluate the effects of H(2)S on inflammatory response induced in host oral/gingival epithelial cells. Porphyromonas gingivalis (Pg) produced the most H(2)S in culture, which, in turn, resulted in the promotion of proinflammatory cytokine IL-8 from both gingival and oral epithelial cells. The up-regulation of IL-8 expression was reproduced by the exogenously applied H(2)S. Furthermore, the mutant strains of Pg that do not produce major soluble virulent factors, i.e. gingipains, still showed the production of H(2)S, as well as the promotion of epithelial IL-8 production, which was abrogated by H(2)S scavenging reagents. These results demonstrated that Pg produces a concentration of H(2)S capable of up-regulating IL-8 expression induced in gingival and oral epithelial cells, revealing a possible mechanism that may promote the inflammation in periodontal disease. PMID:19932683

  5. Bacteria-Derived Hydrogen Sulfide Promotes IL-8 Production from Epithelial Cells

    PubMed Central

    Chen, Weilin; Kajiya, Mikihito; Giro, Gabriela; Ouhara, Kazuhisa; Mackler, Harrison E.; Mawardi, Hani; Boisvert, Heike; Duncan, Margaret J.; Sato, Kimihiro; Kawai, Toshihisa

    2010-01-01

    Hydrogen sulfide (H2S), a volatile sulfur compound, is implicated as a cause of inflammation, especially when it is produced by bacteria colonizing gastrointestinal organs. However, it is unclear if H2S produced by periodontal pathogens affects the inflammatory responses mediated by oral/gingival epithelial cells. Therefore, the aims of this study were 1) to compare the in vitro production of H2S among 14 strains of oral bacteria and 2) to evaluate the effects of H2S on inflammatory response induced in host oral/gingival epithelial cells. P. gingivalis (Pg) produced the most H2S in culture, which, in turn, resulted in the promotion of proinflammatory cytokine IL-8 from both gingival and oral epithelial cells. The up-regulation of IL-8 expression was reproduced by the exogenously applied H2S. Furthermore, the mutant strains of Pg that do not produce major soluble virulent factors, i.e. gingipains, still showed the production of H2S, as well as the promotion of epithelial IL-8 production, which was abrogated by H2S scavenging reagents. These results demonstrated that Pg produces a concentration of H2S capable of up-regulating IL-8 expression induced in gingival and oral epithelial cells, revealing a possible mechanism that may promote the inflammation in periodontal disease. PMID:19932683

  6. Hydrogen sulfide lowers proliferation and induces protective autophagy in colon epithelial cells.

    PubMed

    Wu, Ya C; Wang, Xiao J; Yu, Le; Chan, Francis K L; Cheng, Alfred S L; Yu, Jun; Sung, Joseph J Y; Wu, William K K; Cho, Chi H

    2012-01-01

    Hydrogen sulfide (H(2)S) is a gaseous bacterial metabolite that reaches high levels in the large intestine. In the present study, the effect of H(2)S on the proliferation of normal and cancerous colon epithelial cells was investigated. An immortalized colon epithelial cell line (YAMC) and a panel of colon cancer cell lines (HT-29, SW1116, HCT116) were exposed to H(2)S at concentrations similar to those found in the human colon. H(2)S inhibited normal and cancerous colon epithelial cell proliferation as measured by MTT assay. The anti-mitogenic effect of H(2)S was accompanied by G(1)-phase cell cycle arrest and the induction of the cyclin-dependent kinase inhibitor p21(Cip). Moreover, exposure to H(2)S led to features characteristic of autophagy, including increased formation of LC3B(+) autophagic vacuoles and acidic vesicular organelles as determined by immunofluorescence and acridine orange staining, respectively. Abolition of autophagy by RNA interference targeting Vps34 or Atg7 enhanced the anti-proliferative effect of H(2)S. Further mechanistic investigation revealed that H(2)S stimulated the phosphorylation of AMP-activated protein kinase (AMPK) and inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and S6 kinase. Inhibition of AMPK significantly reversed H(2)S-induced autophagy and inhibition of cell proliferation. Collectively, we demonstrate that H(2)S inhibits colon epithelial cell proliferation and induces protective autophagy via the AMPK pathway. PMID:22679478

  7. Superoxide Mediates Depressive Effects Induced by Hydrogen Sulfide in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats.

    PubMed

    Yu, Haiyun; Xu, Haiyan; Liu, Xiaoni; Zhang, Nana; He, Anqi; Yu, Jerry; Lu, Ning

    2015-01-01

    Hydrogen sulfide (H2S) plays a crucial role in the regulation of blood pressure and oxidative stress. In the present study, we tested the hypothesis that H2S exerts its cardiovascular effects by reducing oxidative stress via inhibition of NADPH oxidase activity in the rostral ventrolateral medulla (RVLM). We examined cell distributions of cystathionine-?-synthase (CBS) and effects of H2S on reactive oxygen species (ROS) and mean arterial blood pressure (MAP) in spontaneously hypertensive rats (SHRs). We found that CBS was expressed in neurons of the RVLM, and the expression was lower in SHRs than in Wistar-Kyoto rats. Microinjection of NaHS (H2S donor), S-adenosyl-l-methionine (SAM, a CBS agonist), or Apocynin (NADPH oxidase inhibitor) into the RVLM reduced the ROS level, NADPH oxidase activity, and MAP, whereas microinjection of hydroxylamine hydrochloride (HA, a CBS inhibitor) increased MAP. Furthermore, intracerebroventricular infusion of NaHS inhibited phosphorylation of p47(phox), a key step of NADPH oxidase activation. Since decreasing ROS level in the RVLM reduces MAP and heart rate and increasing H2S reduces ROS production, we conclude that H2S exerts an antihypertensive effect via suppressing ROS production. H2S, as an antioxidant, may be a potential target for cardiovascular diseases. PMID:26078823

  8. Effects of hydrogen sulfide on high glucose-induced glomerular podocyte injury in mice.

    PubMed

    Liu, Ye; Zhao, Huichen; Qiang, Ye; Qian, Guanfang; Lu, Shengxia; Chen, Jicui; Wang, Xiangdong; Guan, Qingbo; Liu, Yuantao; Fu, Yuqin

    2015-01-01

    The aim of this study was to assess the effects of hydrogen sulfide on high glucose-induced mouse podocyte (MPC) injury and the underlying mechanisms. Mouse podocytes were randomly divided into 4 groups, including high glucose (HG), normal glucose (NG), normal glucose + DL-propargylglycine (PPG), and high glucose + NaHS (HG + NaHS) groups for treatment. Then, ZO-2, nephrin, ?-catenin, and cystathionine ?-lyase (CSE) protein expression levels were determined by western blot. We found that high glucose significantly reduced nephrin, ZO-2, and CSE expression levels (P<0.05), and overtly elevated ?-catenin amounts (P<0.05), in a time-dependent manner. Likewise, PPG at different concentrations in normal glucose resulted in significantly lower CSE, ZO-2, and nephrin levels (P<0.05), and increased ?-catenin amounts (P<0.05). Interestingly, significantly increased ZO-2 and nephrin levels, and overtly reduced ?-catenin amounts were observed in the HG + NaHS group compared with HG treated cells (P<0.01). Compared with NG treated cells, decreased ZO-2 and nephrin levels and higher ?-catenin amounts were obtained in the HG + NaHS group. In conclusion,CSE downregulation contributes to hyperglycemia induced podocyte injury, which is alleviated by exogenous H2S possibly through ZO-2 upregulation and the subsequent suppression of Wnt/?-catenin pathway. PMID:26261567

  9. Roles of Hydrogen Sulfide in the Pathogenesis of Diabetes Mellitus and Its Complications

    PubMed Central

    2012-01-01

    Abstract Significance Diabetes and its complications represent a major socioeconomic problem. Recent Advances Changes in the balance of hydrogen sulfide (H2S) play an important role in the pathogenesis of β-cell dysfunction that occurs in response to type 1 and type 2 diabetes. In addition, changes in H2S homeostasis also play a role in the pathogenesis of endothelial injury, which develop on the basis of chronically or intermittently elevated circulating glucose levels in diabetes. Critical Issues In the first part of this review, experimental evidence is summarized implicating H2S overproduction as a causative factor in the pathogenesis of β-cell death in diabetes. In the second part of our review, experimental evidence is presented supporting the role of H2S deficiency (as a result of increased H2S consumption by hyperglycemic cells) in the pathogenesis of diabetic endothelial dysfunction, diabetic nephropathy, and cardiomyopathy. Future Directions In the final section of the review, future research directions and potential experimental therapeutic approaches around the pharmacological modulation of H2S homeostasis in diabetes are discussed. PMID:22149162

  10. Hydrogen sulfide-releasing NSAIDs attenuate neuroinflammation induced by microglial and astrocytic activation.

    PubMed

    Lee, Moonhee; Sparatore, Anna; Del Soldato, Piero; McGeer, Edith; McGeer, Patrick L

    2010-01-01

    Endogenously generated hydrogen sulfide (H(2)S) may have multiple functions in brain. It has been shown that H(2)S attenuates the expression of pro-inflammatory cytokines by lipopolysaccharide (LPS)-activated microglia. Here we demonstrate a neuroprotective effect of NaSH and three H(2)S-releasing compounds, ADT-OH, S-diclofenac, and S-aspirin. When activated by LPS and gamma-interferon, human microglia and THP-1 cells release materials that are toxic to human neuroblastoma SH-SY5Y cells. These phenomena also occur with gamma-interferon-stimulated human astroglia and U118 cells. When these cell types are pretreated with aspirin, diclofenac, NASH, or ADT-OH, the supernatants are significantly less toxic. When they are treated with the NSAID-H(2)S hybrid molecules S-diclofenac and S-aspirin, which are here referred to as S-NSAIDs, there is a significant enhancement of the protection. The effect is concentration and incubation time dependent. Such pretreatment also reduces the release of the proinflammatory mediators TNFalpha, IL-6, and nitric oxide. The H(2)S-releasing compounds are without effect when applied directly to SH-SY5Y cells. These data suggest that hybrid H(2)S releasing compounds have significant antiinflammatory properties and may be candidates for treating neurodegenerative disorders that have a prominent neuroinflammatory component such as Alzheimer disease and Parkinson disease. PMID:19544392

  11. An Antifungal Role of Hydrogen Sulfide on the Postharvest Pathogens Aspergillus niger and Penicillium italicum

    PubMed Central

    Li, Yan-Hong; Hu, Liang-Bin; Yan, Hong; Liu, Yong-Sheng; Zhang, Hua

    2014-01-01

    In this research, the antifungal role of hydrogen sulfide (H2S) on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS) effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS) in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD) and catalase (CAT) genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation. PMID:25101960

  12. Spatial distribution of hydrogen sulfide from two geothermal power plants in complex terrain

    NASA Astrophysics Data System (ADS)

    Olafsdottir, S.; Gardarsson, S. M.; Andradottir, H. O.

    2014-01-01

    Concerns have arisen about the health impact and odor annoyance of hydrogen sulfide (H2S) emissions associated with geothermal power production. Measurements have been made at stationary measuring stations in inhabited areas but little is known about the spatial behavior of the H2S plumes. This study presents field measurements of the spatial distribution of the ground concentration of H2S within a 30 km radius of two geothermal power plants during 20 distinct events spanning one year. The results showed that high H2S concentration was correlated with high air stability, low wind speed and absence of precipitation. The odor threshold (11 ?g m-3) was exceeded in all events. The instantaneous measurements exceeded the 24-h average national health limit (50 ?g m-3) up to 26 km from the power plants. The shape of the measured plumes at the same location was similar between events, indicating repeated patterns in plume distribution. Convergence of plumes was observed due to spatial variability in wind direction. Plumes were found to follow mountain passes and accumulate alongside a mountain range. AERMOD modeling demonstrated that narrower plumes with higher concentration can be expected for smoother terrain, such as lakes, consistent with measurements.

  13. Superoxide Mediates Depressive Effects Induced by Hydrogen Sulfide in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats

    PubMed Central

    Yu, Haiyun; Xu, Haiyan; Liu, Xiaoni; Zhang, Nana; He, Anqi; Yu, Jerry; Lu, Ning

    2015-01-01

    Hydrogen sulfide (H2S) plays a crucial role in the regulation of blood pressure and oxidative stress. In the present study, we tested the hypothesis that H2S exerts its cardiovascular effects by reducing oxidative stress via inhibition of NADPH oxidase activity in the rostral ventrolateral medulla (RVLM). We examined cell distributions of cystathionine-?-synthase (CBS) and effects of H2S on reactive oxygen species (ROS) and mean arterial blood pressure (MAP) in spontaneously hypertensive rats (SHRs). We found that CBS was expressed in neurons of the RVLM, and the expression was lower in SHRs than in Wistar-Kyoto rats. Microinjection of NaHS (H2S donor), S-adenosyl-l-methionine (SAM, a CBS agonist), or Apocynin (NADPH oxidase inhibitor) into the RVLM reduced the ROS level, NADPH oxidase activity, and MAP, whereas microinjection of hydroxylamine hydrochloride (HA, a CBS inhibitor) increased MAP. Furthermore, intracerebroventricular infusion of NaHS inhibited phosphorylation of p47phox, a key step of NADPH oxidase activation. Since decreasing ROS level in the RVLM reduces MAP and heart rate and increasing H2S reduces ROS production, we conclude that H2S exerts an antihypertensive effect via suppressing ROS production. H2S, as an antioxidant, may be a potential target for cardiovascular diseases. PMID:26078823

  14. Endogenous generation of hydrogen sulfide and its regulation in Shewanella oneidensis

    PubMed Central

    Wu, Genfu; Li, Ning; Mao, Yinting; Zhou, Guangqi; Gao, Haichun

    2015-01-01

    Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions across all domains of life. In this study, mechanisms of endogenous H2S generation in Shewanella oneidensis were investigated. As a research model with highly diverse anaerobic respiratory pathways, the microorganism is able to produce H2S by respiring on a variety of sulfur-containing compounds with SirACD and PsrABC enzymatic complexes, as well as through cysteine degradation with three enzymes, MdeA, SO_1095, and SseA. We showed that the SirACD and PsrABC complexes, which are predominantly, if not exclusively, responsible for H2S generation via respiration of sulfur species, do not interplay with each other. Strikingly, a screen for regulators controlling endogenous H2S generation by transposon mutagenesis identified global regulator Crp to be essential to all H2S-generating processes. In contrast, Fnr and Arc, two other global regulators that have a role in respiration, are dispensable in regulating H2S generation via respiration of sulfur species. Interestingly, Arc is involved in the H2S generation through cysteine degradation by repressing expression of the mdeA gene. We further showed that expression of the sirA and psrABC operons is subjected to direct regulation of Crp, but the mechanisms underlying the requirement of Crp for H2S generation through cysteine degradation remain elusive. PMID:25972854

  15. Operando spectroscopic analysis of an amorphous cobalt sulfide hydrogen evolution electrocatalyst.

    PubMed

    Kornienko, Nikolay; Resasco, Joaquin; Becknell, Nigel; Jiang, Chang-Ming; Liu, Yi-Sheng; Nie, Kaiqi; Sun, Xuhui; Guo, Jinghua; Leone, Stephen R; Yang, Peidong

    2015-06-17

    The generation of chemical fuel in the form of molecular H2 via the electrolysis of water is regarded to be a promising approach to convert incident solar power into an energy storage medium. Highly efficient and cost-effective catalysts are required to make such an approach practical on a large scale. Recently, a number of amorphous hydrogen evolution reaction (HER) catalysts have emerged that show promise in terms of scalability and reactivity, yet remain poorly understood. In this work, we utilize Raman spectroscopy and X-ray absorption spectroscopy (XAS) as a tool to elucidate the structure and function of an amorphous cobalt sulfide (CoSx) catalyst. Ex situ measurements reveal that the as-deposited CoSx catalyst is composed of small clusters in which the cobalt is surrounded by both sulfur and oxygen. Operando experiments, performed while the CoSx is catalyzing the HER, yield a molecular model in which cobalt is in an octahedral CoS2-like state where the cobalt center is predominantly surrounded by a first shell of sulfur atoms, which, in turn, are preferentially exposed to electrolyte relative to bulk CoS2. We surmise that these CoS2-like clusters form under cathodic polarization and expose a high density of catalytically active sulfur sites for the HER. PMID:26051104

  16. Hydrogen-sulfide-mediated vasodilatory effect of nucleoside 5'-monophosphorothioates in perivascular adipose tissue.

    PubMed

    Be?towski, Jerzy; Guranowski, Andrzej; Jamroz-Wi?niewska, Anna; Wolski, Andrzej; Ha?as, Krzysztof

    2015-07-01

    Hydrogen sulfide (H2S) is synthesized in perivascular adipose tissue (PVAT) and induces vasorelaxation. We examined whether the sulfur-containing AMP and GMP analogs AMPS and GMPS can serve as the H2S donors in PVAT. H2S production by isolated rat periaortic adipose tissue (PAT) was measured with a polarographic sensor. In addition, phenylephrine-induced contractility of aortic rings with (+) or without (-) PAT was examined. Isolated PAT produced H2S from AMPS or GMPS in the presence of the P2X7 receptor agonist BzATP. Phenylephrine-induced contractility of PAT(+) rings was lower than of PAT(-) rings. AMPS or GMPS had no effect on the contractility of PAT(-) rings, but used together with BzATP reduced the contractility of PAT(+) rings when endogenous H2S production was inhibited with propargylglycine. A high-fat diet reduced endogenous H2S production by PAT. Interestingly, AMPS and GMPS were converted to H2S by PAT of obese rats, and reduced contractility of PAT(+) aortic rings isolated from these animals even in the absence of BzATP. We conclude that (i) AMPS and GMPS can be hydrolyzed to H2S by PAT when P2X7 receptors are activated, (ii) a high-fat diet impairs endogenous H2S production by PAT, (iii) AMPS and GMPS restore the anticontractile effects of PAT in obese animals without P2X7 stimulation. PMID:26120822

  17. Case report: Profound neurobehavioral deficits in an oil field worker overcome by hydrogen sulfide

    SciTech Connect

    Kilburn, K.H. )

    1993-11-01

    A 24-year-old oil well tester was rendered semiconscious by hydrogen sulfide (H2S). He received oxygen and was hospitalized but released in 30 minutes. The next day, nausea, vomiting, diarrhea, and incontinence of urine and stool led to rehospitalization. These problems and leg shaking, dizziness, sweating, trouble sleeping, and nightmares prevented his return to work. A physical examination, chest x-ray, and pulmonary function tests were normal 39 months after the episode but vibration sense was diminished. Two choice visual reaction times were delayed. Balance was highly abnormal (5 to 6 cm/sec) with eyes closed. Blink reflex latency was slow (R-1 17.5 msec versus normal 14.3 msec). Numbers written on finger tips were not recognized. Verbal and visual recall were impaired but overlearned memory was intact. Cognitive functions measured by Culture Fair, block design, and digit symbol were impaired. Perceptual motor was slow. Scores for confusion, tension-anxiety, depression, and fatigue were elevated and vigor was reduced. Forty-nine months after exposure his reaction time, sway speed, and color vision had not improved. His recall and his cognitive, constructional, and psychomotor speeds had improved but remained abnormal. These deficits are most likely due to H2S. Similar testing of other survivors is recommended.

  18. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System.

    PubMed

    Nagpure, B V; Bian, Jin-Song

    2016-01-01

    Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, "gasotransmitters" in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress. PMID:26640616

  19. Hydrogen sulfide inhibits enzymatic browning of fresh-cut lotus root slices by regulating phenolic metabolism.

    PubMed

    Sun, Ying; Zhang, Wei; Zeng, Tao; Nie, Qixing; Zhang, Fengying; Zhu, Liqin

    2015-06-15

    The effect of fumigation with hydrogen sulfide (H2S) gas on inhibiting enzymatic browning of fresh-cut lotus root slices was investigated. Browning degree, changes in color, total phenol content, superoxide anion production rate (O2(-)), H2O2 content, antioxidant capacities (DPPH radical scavenging ability, ABTS radical scavenging activity and the reducing power) and activities of the phenol metabolism-associated enzymes including phenylalanine ammonialyase (PAL), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) were evaluated. The results showed that treatment with 15 μl L(-1) H2S significantly inhibited the browning of fresh-cut lotus root slices (P<0.05), reduced significantly O2(-) production rate and H2O2 content, and enhanced antioxidant capacities (P<0.05). PPO and POD activities in the fresh-cut lotus root slices were also significantly inhibited by treatment with H2S (P<0.05). This study suggested that treatment with exogenous H2S could inhibit the browning of fresh-cut lotus root slices by enhancing antioxidant capacities to alleviate the oxidative damage. PMID:25660900

  20. Anti-Cancer Activity of New Designer Hydrogen Sulfide-Donating Hybrids

    PubMed Central

    2014-01-01

    Abstract Significance: Hydrogen sulfide (H2S) is likely to join nitric oxide (NO) and carbon monoxide (CO) as the third gaseous transmitter, influencing an array of intracellular signaling cascades. Thus, H2S is implicated in numerous physiological processes and in the pathology of various diseases. Recent Advances: H2S-donating agents that liberate H2S slowly either alone or in combination with NO, the so-called NOSH compounds, are being synthesized, and these have been shown to have great potential against cancer. Critical Issues: An accurate determination of H2S levels is challenging. H2S and NO share many similar actions; do these similarities act to potentiate each other? Since many actions of H2S appear to be mediated through inhibition of inflammation and Nuclear factor kappa-light-chain-enhancer of activated B cells is a central player in this scenario, does S-nitrosylation of this transcription factor by NO affect its S-sulfhydration by H2S and vice versa? Future Directions: Deciphering the molecular targets of these novel hybrid agents and having genetically engineered animals should help us move toward targeted therapeutic applications. Human safety data with these new hybrids is essential. Antioxid. Redox Signal. 20, 831846. PMID:23581880

  1. Hydrogen sulfide, a potential novel drug, attenuates concanavalin A-induced hepatitis

    PubMed Central

    Cheng, Ping; Chen, Kan; Xia, Yujing; Dai, Weiqi; Wang, Fan; Shen, Miao; Wang, Chengfen; Yang, Jing; Zhu, Rong; Zhang, Huawei; Li, Jingjing; Zheng, Yuanyuan; Wang, Junshan; Zhang, Yan; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

    2014-01-01

    Background Hydrogen sulfide (H2S) is known to exert anti-inflammatory properties. Apoptosis and autophagy play important roles in concanavalin A (Con A)-induced acute hepatitis. The purpose of this study was to explore both the effect and mechanism of H2S on Con A-induced acute hepatitis. Methods BALB/c mice were randomized into sham group, Con A-injection group, and 14 ?mol/kg of sodium hydrosulfide (NaHS, an H2S donor) pretreatment group. Results Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by NaHS pretreatment. NaHS pretreatment significantly reduced the levels of interleukin-6 and tumor necrosis factor-? compared with those of the Con A group. The expression of Bcl-2, Bax, Beclin-1, and LC3-2, which play important roles in the apoptosis and autophagy pathways, were also clearly affected by NaHS. Furthermore, NaHS affected the p-mTOR and p-AKT. Conclusion H2S attenuates Con A-induced acute hepatitis by inhibiting apoptosis and autophagy, in part, through activation of the PtdIns3K-AKT1 signaling pathway. PMID:25246769

  2. Endogenous generation of hydrogen sulfide and its regulation in Shewanella oneidensis.

    PubMed

    Wu, Genfu; Li, Ning; Mao, Yinting; Zhou, Guangqi; Gao, Haichun

    2015-01-01

    Hydrogen sulfide (H2S) has been recognized as a physiological mediator with a variety of functions across all domains of life. In this study, mechanisms of endogenous H2S generation in Shewanella oneidensis were investigated. As a research model with highly diverse anaerobic respiratory pathways, the microorganism is able to produce H2S by respiring on a variety of sulfur-containing compounds with SirACD and PsrABC enzymatic complexes, as well as through cysteine degradation with three enzymes, MdeA, SO_1095, and SseA. We showed that the SirACD and PsrABC complexes, which are predominantly, if not exclusively, responsible for H2S generation via respiration of sulfur species, do not interplay with each other. Strikingly, a screen for regulators controlling endogenous H2S generation by transposon mutagenesis identified global regulator Crp to be essential to all H2S-generating processes. In contrast, Fnr and Arc, two other global regulators that have a role in respiration, are dispensable in regulating H2S generation via respiration of sulfur species. Interestingly, Arc is involved in the H2S generation through cysteine degradation by repressing expression of the mdeA gene. We further showed that expression of the sirA and psrABC operons is subjected to direct regulation of Crp, but the mechanisms underlying the requirement of Crp for H2S generation through cysteine degradation remain elusive. PMID:25972854

  3. Effectiveness and mechanisms of hydrogen sulfide adsorption by camphor-derived biochar.

    PubMed

    Shang, Guofeng; Shen, Guoqing; Wang, Tingting; Chen, Qin

    2012-08-01

    The characteristics and mechanisms of hydrogen sulfide (H2S) adsorption on a biochar through pyrolysis at various temperatures (100 to 500 degrees C) were investigated. The biochar used in the current study was derived from the camphor tree (Cinnamomum camphora). The samples were ground and sieved to produceparticle sizes of 0.4 mm to 1.25 mm, 0.3 mm to 0.4 mm, and <0.3 mm. The H2S breakthrough capacity was measured using a laboratory-designed test. The surface properties of the biochar were characterized using pH and Fourier-transform infrared spectroscopy (FTIR) analysis. The results obtained demonstrate that all camphor-derived biochars were effective in H2S sorption. Certain threshold ranges ofthepyrolysis temperature and surfacepH were observed, which, when exceeded, have dramatic effects on the H2S adsorption capacity. The sorption capacity ranged from 1.2 mg/g to 121.4 mg/g. The biochar with 0.3 mm to 0.4 mm particle size possesses a maximum sorption capacity at 400 degrees C. The pH and FTIR analysis results showed that carboxylic and hydroxide radical groups were responsible for H2S sorption. These observations will be helpful in designing biochar as engineered sorbents for the removal of H2S. PMID:22916434

  4. Ferric Iron and Cobalt (III) compounds to safely decrease hydrogen sulfide in the body?

    PubMed

    Van de Louw, Andry; Haouzi, Philippe

    2013-08-10

    To sort out the putative roles of endogenous hydrogen sulfide (H2S) in clinical conditions wherein systemic inflammation or hypoxia is present, it becomes crucial to develop approaches capable of affecting H2S concentration that can be safely applied in humans. We have investigated a paradigm, which could achieve such a goal, using vitamin B12 (vit.B12), at the dose recommended in cyanide poisoning, and very low levels of methemoglobin (MetHb). Hydroxocobalamin in the plasma, supernatant of kidney, and heart tissue homogenates of rats that had received vit.B12 (140 mg.kg(-1) intravenous) was found in the μM range. Exogenous H2S (100 μM) added to the plasma or supernatants of these rats decreased at a significantly higher rate than in control rats. In the latter however a spontaneous oxidation of exogenous H2S occurred. In vitro, hydroxocobalamin solution (100 μM) decreased, within <2 min, an equimolar concentration of H2S by 80%. Three to five percent MetHb prevented H2S induced hyperventilation in vivo and decreased exogenous H2S in vitro by 25-40 μM within 30 s. Our observations lead to the hypothesis that innocuous levels of MetHb and vit.B12 could be a used as an effective and safe way to test the role of endogenous H2S in vivo. PMID:22233239

  5. Leukocyte trafficking and pain behavioral responses to a hydrogen sulfide donor in acute monoarthritis.

    PubMed

    Andruski, Benjamin; McCafferty, Donna-Marie; Ignacy, Teegan; Millen, Brandie; McDougall, Jason J

    2008-09-01

    Hydrogen sulfide (H(2)S) is an endogenous gaseous mediator with the ability to modulate tissue inflammation and pain. The aim of this study was to determine the effect of an H(2)S donor (Na(2)S) on leukocyte-endothelium interactions, blood flow, and pain sensation in acutely inflamed knee joints. Acute arthritis was induced in urethane anesthetized C57bl/6 mice by intra-articular injection of kaolin/carrageenan (24-h recovery), and the effect of local administration of Na(2)S on leukocyte trafficking was measured by intravital microscopy. Synovial blood flow was measured in inflamed knees by laser Doppler perfusion imaging. Finally, the effect of an intra-articular injection of Na(2)S on joint pain in control and inflamed rats was determined by hindlimb incapacitance and von Frey hair algesiometry. Local administration of an H(2)S donor to inflamed knees caused a dose-dependent reduction in leukocyte adherence and an increase in leukocyte velocity. These effects could be inhibited by coadministration of the ATP-sensitive K(+) channel blocker glibenclamide. Local administration of Na(2)S to inflamed joints caused a pronounced vasoconstrictor response; however, there was no observable effect of Na(2)S on joint pain. These findings establish H(2)S as a novel signaling molecule in rodent knee joints. H(2)S exhibits potent anti-inflammatory properties, but with no detectable effect on joint pain. PMID:18667709

  6. Electrocatalytic Hydrogen Evolution from Molybdenum Sulfide-Polymer Composite Films on Carbon Electrodes.

    PubMed

    Lattach, Youssef; Deronzier, Alain; Moutet, Jean-Claude

    2015-07-29

    The design of more efficient catalytic electrodes remains an important objective for the development of water splitting electrolyzers. In this context a structured composite cathode material has been synthesized by electrodeposition of molybdenum sulfide (MoSx) into a poly(pyrrole-alkylammonium) matrix, previously coated onto carbon electrodes by oxidative electropolymerization of a pyrrole-alkylammonium monomer. The composite material showed an efficient electrocatalytic activity toward proton reduction and the hydrogen evolution reaction (HER). Data from Tafel plots have demonstrated that the electron transfer rate in the composite films is fast, in agreement with the high catalytic activity of this cathode material. Bulk electrolysis of acidic water at carbon foam electrodes modified with the composite have shown that the cathodes display a high catalytic activity and a reasonable operational stability, largely exceeding that of regular amorphous MoSx electrodeposited on naked carbon foam. The enhanced catalytic performances of the composite electrode material were attributed to the structuration of the composite, which led to a homogeneous distribution of the catalyst on the carbon foam network, as shown by SEM characterizations. PMID:26147828

  7. High-pressure hydrogen sulfide from first principles: a strongly anharmonic phonon-mediated superconductor.

    PubMed

    Errea, Ion; Calandra, Matteo; Pickard, Chris J; Nelson, Joseph; Needs, Richard J; Li, Yinwei; Liu, Hanyu; Zhang, Yunwei; Ma, Yanming; Mauri, Francesco

    2015-04-17

    We use first-principles calculations to study structural, vibrational, and superconducting properties of H_{2}S at pressures P?200??GPa. The inclusion of zero-point energy leads to two different possible dissociations of H2S, namely 3H2S?2H3S+S and 5H2S?3H3S+HS2, where both H3S and HS2 are metallic. For H3S, we perform nonperturbative calculations of anharmonic effects within the self-consistent harmonic approximation and show that the harmonic approximation strongly overestimates the electron-phonon interaction (??2.64 at 200 GPa) and Tc. Anharmonicity hardens H?S bond-stretching modes and softens H?S bond-bending modes. As a result, the electron-phonon coupling is suppressed by 30% (??1.84 at 200 GPa). Moreover, while at the harmonic level Tc decreases with increasing pressure, the inclusion of anharmonicity leads to a Tc that is almost independent of pressure. High-pressure hydrogen sulfide is a strongly anharmonic superconductor. PMID:25933334

  8. Removal of hydrogen sulfide by immobilized Thiobacillus thioparus in a biotrickling filter packed with polyurethane foam.

    PubMed

    Ramrez, Martn; Gmez, Jos Manuel; Aroca, Germn; Cantero, Domingo

    2009-11-01

    In the work described here, a biotrickling filter with Thiobacillus thioparus (ATCC 23645) immobilized on polyurethane foam is proposed for the removal of hydrogen sulfide contained in air. The effect of surface velocity of the recirculation medium (5.9-1.2 m/h), sulfate concentration inhibition (3.0-10.7 g/L), pH (6.0-8.2), empty bed residence time (EBRT) (150-11 s) for constant loads of 11.5 and 2.9 g S/m(3)/h, and pressure drop of the system were investigated. The total amount of biomass immobilized on the carrier was 8.2+/-1.3x10(10) cells/g. The optimal values of the operating variables were: pH between 7.0 and 7.5, surface velocity of 5.9 m/h and sulfate concentration below 5 g/L. The critical EC value was 14.9 g S/m(3)/h (removal efficiency of 99.8%) and the EC(max) was 55.0 g S/m(3)/h (removal efficiency of 79.8%) for an EBRT of 150 s. For loads of 2.89+/-0.05 and 11.5+/-0.1 g S/m(3)/h, the removal efficiency was higher than 99% for an EBRT over 90 s. PMID:19501506

  9. Emergence of Hydrogen Sulfide as an Endogenous Gaseous Signaling Molecule in Cardiovascular Disease

    PubMed Central

    Polhemus, David J.; Lefer, David J.

    2014-01-01

    Long recognized as a malodorous and highly toxic gas, recent experimental studies have revealed that hydrogen sulfide (H2S) is produced enzymatically in all mammalian species including man and exerts a number of critical actions to promote cardiovascular homeostasis and health. During the past 15 years, scientists have determined that H2S is produced by three endogenous enzymes and exerts powerful effects on endothelial cells, smooth muscle cells, inflammatory cells, mitochondria, endoplasmic reticulum, and nuclear transcription factors. These effects have been reported in multiple organ systems and the vast majority of data clearly indicate that H2S produced by the endogenous enzymes exerts cytoprotective actions. Recent preclinical studies investigating cardiovascular diseases have demonstrated that the administration of physiological or pharmacological levels of H2S attenuates myocardial injury, protects blood vessels, limits inflammation, and regulates blood pressure. H2S has emerged as a critical cardiovascular signaling molecule similar to nitric oxide (NO) and carbon monoxide (CO) with a profound impact on the heart and circulation (Figure 1). Our improved understanding of how H2S elicits protective actions, coupled with the very rapid development of novel H2S releasing agents, has resulted in heightened enthusiasm for the clinical translation of this ephemeral gaseous molecule. This review will examine our current state of knowledge regarding the actions of H2S within the cardiovascular system with an emphasis on the therapeutic potential and molecular crosstalk between H2S, NO, and CO. PMID:24526678

  10. Comparative Proteomic Analysis of Differentially Expressed Proteins Induced by Hydrogen Sulfide in Spinacia oleracea Leaves

    PubMed Central

    Chen, Juan; Liu, Ting-Wu; Hu, Wen-Jun; Simon, Martin; Wang, Wen-Hua; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

    2014-01-01

    Hydrogen sulfide (H2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H2S. PMID:25181351

  11. Hydrogen sulfide-releasing naproxen suppresses colon cancer cell growth and inhibits NF-?B signaling

    PubMed Central

    Kodela, Ravinder; Nath, Niharika; Chattopadhyay, Mitali; Nesbitt, Diandra E; Velzquez-Martnez, Carlos A; Kashfi, Khosrow

    2015-01-01

    Colorectal cancer (CRC) is the second leading cause of death due to cancer and the third most common cancer in men and women in the USA. Nuclear factor kappa B (NF-?B) is known to be activated in CRC and is strongly implicated in its development and progression. Therefore, activated NF-?B constitutes a bona fide target for drug development in this type of malignancy. Many epidemiological and interventional studies have established nonsteroidal anti-inflammatory drugs (NSAIDs) as a viable chemopreventive strategy against CRC. Our previous studies have shown that several novel hydrogen sulfide-releasing NSAIDs are promising anticancer agents and are safer derivatives of NSAIDs. In this study, we examined the growth inhibitory effect of a novel H2S-releasing naproxen (HS-NAP), which has a repertoire as a cardiovascular-safe NSAID, for its effects on cell proliferation, cell cycle phase transitions, and apoptosis using HT-29 human colon cancer cells. We also investigated its effect as a chemo-preventive agent in a xenograft mouse model. HS-NAP suppressed the growth of HT-29 cells by induction of G0/G1 arrest and apoptosis and downregulated NF-?B. Tumor xenografts in mice were significantly reduced in volume. The decrease in tumor mass was associated with a reduction of cell proliferation, induction of apoptosis, and decreases in NF-?B levels in vivo. Therefore, HS-NAP demonstrates strong anticancer potential in CRC. PMID:26346117

  12. Hydrogen sulfide-linked sulfhydration of NF-κB mediates its anti-apoptotic actions

    PubMed Central

    Sen, Nilkantha; Paul, Bindu D.; Gadalla, Moataz M.; Mustafa, Asif K.; Sen, Tanusree; Xu, Risheng; Kim, Seyun; Snyder, Solomon H.

    2011-01-01

    Summary Nuclear factor κB (NF-κB) is an anti-apoptotic transcription factor. We show that the anti-apoptotic actions of NF-κB are mediated by hydrogen sulfide (H2S) synthesized by cystathionine gamma-lyase (CSE). TNFα treatment triples H2S generation by stimulating binding of SP1 to the CSE promoter. H2S generated by CSE stimulates DNA binding and gene activation of NF-κB, processes that are abolished in CSE deleted mice. As CSE deletion leads to decreased glutathione levels, resultant oxidative stress may contribute to alterations in CSE mutant mice. H2S acts by sulfhydrating the p65 subunit of NF-κB at cysteine-38, which promotes its binding to the co-activator ribosomal protein S3 (RPS3). Sulfhydration of p65 predominates early following TNFα treatment, then declines and is succeeded by a reciprocal enhancement of p65 nitrosylation. Anti-apoptotic influences of NF-κB, which are markedly diminished in CSE mutant mice. Thus, sulfhydration of NF-κB appears to be a physiologic determinant of its anti-apoptotic transcriptional activity. PMID:22244329

  13. The Cardioprotective Effects of Hydrogen Sulfide in Heart Diseases: From Molecular Mechanisms to Therapeutic Potential

    PubMed Central

    Shen, Yaqi; Shen, Zhuqing; Luo, Shanshan; Guo, Wei; Zhu, Yi Zhun

    2015-01-01

    Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production. PMID:26078822

  14. Hydrogen sulfide interacts with calcium signaling to enhance the chromium tolerance in Setaria italica.

    PubMed

    Fang, Huihui; Jing, Tao; Liu, Zhiqiang; Zhang, Liping; Jin, Zhuping; Pei, Yanxi

    2014-12-01

    The oscillation of intracellular calcium (Ca(2+)) concentration is a primary event in numerous biological processes in plants, including stress response. Hydrogen sulfide (H2S), an emerging gasotransmitter, was found to have positive effects in plants responding to chromium (Cr(6+)) stress through interacting with Ca(2+) signaling. While Ca(2+) resemblances H2S in mediating biotic and abiotic stresses, crosstalk between the two pathways remains unclear. In this study, Ca(2+) signaling interacted with H2S to produce a complex physiological response, which enhanced the Cr(6+) tolerance in foxtail millet (Setaria italica). Results indicate that Cr(6+) stress activated endogenous H2S synthesis as well as Ca(2+) signaling. Moreover, toxic symptoms caused by Cr(6+) stress were strongly moderated by 50?M H2S and 20mM Ca(2+). Conversely, treatments with H2S synthesis inhibitor and Ca(2+) chelators prior to Cr(6+)-exposure aggravated these toxic symptoms. Interestingly, Ca(2+) upregulated expression of two important factors in metal metabolism, MT3A and PCS, which participated in the biosynthesis of heavy metal chelators, in a H2S-dependent manner to cope with Cr(6+) stress. These findings also suggest that the H2S dependent pathway is a component of the Ca(2+) activating antioxidant system and H2S partially contributes Ca(2+)-activating antioxidant system. PMID:25459298

  15. Role of Cystathionine γ-Lyase/Hydrogen Sulfide Pathway in Cardiovascular Disease: A Novel Therapeutic Strategy?

    PubMed Central

    Pan, Li Long; Liu, Xin Hua; Gong, Qi Hai; Yang, He Bei

    2012-01-01

    Abstract Significance: Hydrogen sulfide (H2S) has traditionally been considered a toxic environmental pollutant. In the late 1990s, the presumed solely harmful role of H2S has been challenged because H2S may also be involved in the maintenance and preservation of cardiovascular homeostasis. Recent Advances: The production of endogenous H2S has been attributed to three key enzymes, cystathionine γ-lyase (CSE), cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase. The recognition of H2S as the third gaseous signaling molecule has stimulated research on a multitude of pathophysiologic events in the cardiovascular system. In particular, important roles in cardiovascular disorder processes are ascribed to the CSE/H2S pathway, such as atherosclerosis, myocardial infarction, hypertension, and shock. Critical Issues: Many biological activities and molecular mechanisms of H2S in the cardiovascular system have been demonstrated in studies using different tools, such as the genetic overexpression of CSE, the direct administration of H2S donors, or the use of H2S-releasing pro-drugs. Unfortunately, the role of the CSE/H2S pathway in cardiovascular disease remains controversial in numerous areas, and many questions regarding the gaseous molecule still remain unanswered. Future Directions: Advances in basic research indicate that the CSE/H2S pathway may provide potential therapeutic targets for treating cardiovascular disorders. But the molecular targets of H2S still need to be identified. Antioxid. Redox Signal. 17, 106–118. PMID:22017202

  16. Hydrogen sulfide and the vasculature: a novel vasculoprotective entity and regulator of nitric oxide bioavailability?

    PubMed Central

    Whiteman, Matthew; Moore, Philip K

    2009-01-01

    Abstract Hydrogen sulfide (H2S) is a well known and pungent toxic gas that has recently been shown to be synthesised in man from the amino acids cystathionine, homocysteine and cysteine by at least two distinct enzymes; cystathionine-γ-lyase and cystathionine-β-synthase. In the past few years, H2S has emerged as a novel and increasingly important mediator in the cardiovascular system but delineating the precise physiology and pathophysiology of H2S is proving to be complex and difficult to unravel with disparate findings reported with cell types, tissue types and animal species reported. Therefore, in this review we summarize the mechanisms by which H2S has been proposed to regulate blood pressure and cardiac function, discuss the mechanistic discrepancies reported in the literature as well as the therapeutic potential of H2S. We also examine the methods of H2S detection in biological fluids, processes for H2S removal and discuss the reported blood levels of H2S in man and animal models of cardiovascular pathology. We also highlight the complex interaction of H2S with nitric oxide in regulating cardiovascular function in health and disease. PMID:19374684

  17. Domino effect: An unusual case of six fatal hydrogen sulfide poisonings in quick succession.

    PubMed

    Barbera, Nunziata; Montana, Angelo; Indorato, Francesca; Arbouche, Nadia; Romano, Guido

    2016-03-01

    Hydrogen sulfide (H2S) is one of the most serious toxic gases encountered in forensic practice. Aside from being a by-product of many industrial processes, this gas is naturally produced during the putrefaction of organic substances. We report six autopsy cases of fatal H2S poisonings from inhalation of H2S gas after an occupational accident. These six men died during the unblocking of a wastewater cistern. The first worker died shortly after clearing the obstruction, the other five died, one by one, as they attempted to help their colleagues. The macroscopic and histological findings are discussed here to provide useful information for future cases. Greenish discoloration of the skin and of internal organs (liver, trachea, esophagus, stomach) was observed, and one case showed signs typical of drowning. We present a very unusual incident, complete with rare photographs and toxicological analysis. In these cases, based on both macroscopic and microscopic findings, the cause of death was most likely an inhibitory effect on cellular cytochrome oxidase causing respiratory failure. PMID:26869537

  18. The sorption of hydrogen sulfide from hot syngas by metal oxides over supports.

    PubMed

    Ko, Tzu-Hsing; Chu, Hsin; Chaung, Lung-Kai

    2005-01-01

    Six 5 wt.% metal sorbents including Mn, Fe, Cu, Co, Ce and Zn supported on gamma-Al2O3, prepared by the incipient wetness impregnation method with calcination at 700 degrees C for 2 h, have been investigated for sorption of hydrogen sulfide in the temperature range of 500-700 degrees C. The sorption experiments were conducted in a fixed-bed reactor in terms of breakthrough curves and characterized by X-ray powder diffraction. The results reveal that the copper and manganese sorbents exhibit the best performance because they provide nearly 100% utilization, but the copper sorbent has a lower sulfur sorption capacity compared with the manganese sorbent. The zinc and cerium sorbents are not good candidates attributed to the vaporization of zinc and unexpected product for cerium. Effects of support materials on 5 wt.% manganese were also investigated by using gamma-Al2O3, SiO2 and TiO2 in this study. Five weight percent Mn/gamma-Al2O3 shows the best performance among support candidates. On the basis of XRPD and BET surface area analysis, TiO2 appears a huge loss in BET surface area associated with a significant formation of rutile form. PMID:15620738

  19. Highly sensitive hydrogen sulfide (H2 S) gas sensors from viral-templated nanocrystalline gold nanowires

    NASA Astrophysics Data System (ADS)

    Moon, Chung Hee; Zhang, Miluo; Myung, Nosang V.; Haberer, Elaine D.

    2014-04-01

    A facile, site-specific viral-templated assembly method was used to fabricate sensitive hydrogen sulfide (H2S) gas sensors at room temperature. A gold-binding M13 bacteriophage served to organize gold nanoparticles into linear arrays which were used as seeds for subsequent nanowire formation through electroless deposition. Nanowire widths and densities within the sensors were modified by electroless deposition time and phage concentration, respectively, to tune device resistance. Chemiresistive H2S gas sensors with superior room temperature sensing performance were produced with sensitivity of 654%/ppmv, theoretical lowest detection limit of 2 ppbv, and 70% recovery within 9 min for 0.025 ppmv. The role of the viral template and associated gold-binding peptide was elucidated by removing organics using a short O2 plasma treatment followed by an ethanol dip. The template and gold-binding peptide were crucial to electrical and sensor performance. Without surface organics, the resistance fell by several orders of magnitude, the sensitivity dropped by more than a factor of 100 to 6%/ppmv, the lower limit of detection increased, and no recovery was detected with dry air flow. Viral templates provide a novel, alternative fabrication route for highly sensitive, nanostructured H2S gas sensors.

  20. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System

    PubMed Central

    Nagpure, B. V.; Bian, Jin-Song

    2016-01-01

    Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, “gasotransmitters” in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress. PMID:26640616

  1. Removal of hydrogen sulfide and sulfur dioxide by carbons impregnated with triethylenediamine.

    PubMed

    Wu, Li-Chun; Chang, Tsu-Hua; Chung, Ying-Chien

    2007-12-01

    Activated carbon (AC) adsorption has long been considered to be a readily available technology for providing protection against exposure to acutely toxic gases. However, ACs without chemical impregnation have proven to be much less efficient than impregnated ACs in terms of gas removal. The impregnated ACs in current use are usually modified with metalloid impregnation agents (ASC-carbons; copper, chromium, or silver) to simultaneously enhance the chemical and physical properties of the ACs in removing specific poisonous gases. These metalloid agents, however, can cause acute poisoning to both humans and the environment, thereby necessitating the search for organic impregnation agents that present a much lower risk. The aim of the study reported here was to assess AC or ASC-carbon impregnated with triethylenediamine (TEDA) in terms of its adsorption capability for simulated hydrogen sulfide (H2S) and sulfur dioxide (SO2) gases. The investigation was undergone in a properly designed laboratory-scale and industrial fume hood evaluation. Using the system reported here, we obtained a significant adsorption: the removal capability for H2S and SO2 was 375 and 229 mg/g-C, respectively. BET measurements, element analysis, scanning electron microscopy, and energy dispersive spectrometry identified the removal mechanism for TEDA-impregnated AC to be both chemical and physical adsorption. Chemical adsorption and oxidation were the primary means by which TEDA-impregnated ASC-carbons removed the simulated gases. PMID:18200931

  2. Performance of a solid oxide fuel cell utilizing hydrogen sulfide as fuel

    NASA Astrophysics Data System (ADS)

    Liu, M.; He, P.; Luo, J. L.; Sanger, A. R.; Chuang, K. T.

    The electrochemical performance of a hydrogen sulfide solid oxide fuel cell having the configuration H 2S, Pt/(ZrO 2) 0.92(Y 2O 3) 0.08/Pt, air has been examined at atmospheric pressure and 750-800C, using both pure and 5% H 2S anode feed streams. The performance of the cell is higher when using diluted H 2S feed compared with pure H 2S feed: current densities up to 100 mA cm -2 and power densities up to 15.4 mW cm -2 have been achieved using diluted H 2S gas (5%) at 800C. However, the platinum anode degrades over time in H 2S stream due to the formation of PtS. Electrochemical oxidation of H 2S on the Pt anode significantly accelerated its degradation. Polarization and impedance spectroscopy measurements show that at low current density ( i) electrochemical reaction is the major cause of polarization in the fuel cell. Ohmic loss due to the resistance of the electrolyte material and the electrical connecting wire is a major part of cell polarization at high i.

  3. Emersion in the mangrove forest fish Rivulus marmoratus: A unique response to hydrogen sulfide

    SciTech Connect

    Abel, D.C.; Koenig, C.C.; Davis, W.P.

    1987-01-01

    The mangrove forest fish Rivulus marmoratus (Cyprinodontidae) has frequently been observed out of water, a phenomenon generally attributed to habitat drying. The hypothesis that hydrogen sulfide, a substance characteristically found in their environment, can serve as a stimulus for emersion, is tested in this study. In the field R. marmoratus was found in water with low to moderate level of H{sub 2}S. In the laboratory, R marmora leaped from water contaminated with H{sub 2}S at ecologically relevant concentrations. Aquatic hypoxia did not induce emersion, but prey capture did. Oxygen consumption by both juveniles and adults decreased significantly in air. These results suggest that avoidance of H{sub 2}S and the ability to survive terrestrial conditions enable this species to permanently occupy an area of the forest unavailable to other fishes. Furthermore, because a variety of stimuli lead to emersion in R. marmoratus, terrestriality in this species is likely a generalized response to environmental stress as well as a means of exploiting terrestrial resources. 16 refs., 1 fig., 2 tabs.

  4. Hydrogen Sulfide Detection Using a Gold Nanoparticle/Metalloprotein Based Probe

    NASA Astrophysics Data System (ADS)

    Meisam, Omidi; Gh., Amoabediny; Yazdian, F.; Habibi-Rezaei, M.

    2014-08-01

    We present a simple method for direct detection of hydrogen sulfide (H2S) in an aqueous solution. This method represents a novel biosensor based on metalloprotein cytochrome c (cyt c) with the localized surface plasmon resonance of gold nanoparticles (AuNPs). For this purpose, we develop a new approach based on attaching chemically-modified cyt c onto AuNPs. Here, by reacting H2S with protein heme center, its conformation changes in the locality of the heme moiety. The conformational changes occurring in the protein alter the spectral characteristics by changing the dielectric properties of AuNPs. The conformational changes of cyt c induced by the H2S interaction are characterized by the UV-visible absorption spectroscopy and the circular dichroism technique. The limit of the detection and sensitivity of the AuNPs/cyt c biosensor are evaluated by using UV-visible spectroscopy. According to the experiments, it is revealed that H2S can be detected at a concentration of 4.0 ?M (1.3 ppb) by the fabricated AuNPs/cyt c biosensor. In addition, the sensor retains activity and gives reproducible results after storage in 4C for 60 d. This simple and cost-effective sensing platform provides a rapid and convenient detection for H2S at concentrations far below the hazardous limit.

  5. A Practical Look at the Chemistry and Biology of Hydrogen Sulfide

    PubMed Central

    2012-01-01

    Abstract Significance: Hydrogen sulfide (H2S) is garnering increasing interest as a biologically relevant signaling molecule. The effects of H2S have now been observed in virtually every organ system and numerous physiological processes. Recent Advances: These studies have not only opened a new field of “gasotransmitter” biology, they have also led to the development of synthetic H2S “donating” compounds with the potential to be parlayed into a variety of therapeutic applications. Critical Issues: Often lost in the exuberance of this new field is a critical examination or understanding of practical aspects of H2S chemistry and biology. This is especially notable in the areas of handling and measuring H2S, evaluating biosynthetic and metabolic pathways, and separating physiological from pharmacological responses. Future Directions: This brief review describes some of the pitfalls in H2S chemistry and biology that can lead or have already led to misleading or erroneous conclusions. The intent is to allow individuals entering or already in this burgeoning field to critically analyze the literature and to assist them in the design of future experiments. Antioxid. Redox Signal. 17, 32–44. PMID:22074253

  6. Inhibitory effect of hydrogen sulfide on ozone-induced airway inflammation, oxidative stress, and bronchial hyperresponsiveness.

    PubMed

    Zhang, Pengyu; Li, Feng; Wiegman, Coen H; Zhang, Min; Hong, Yan; Gong, Jicheng; Chang, Yan; Zhang, Junfeng Jim; Adcock, Ian; Chung, Kian Fan; Zhou, Xin

    2015-01-01

    Exposure to ozone has been associated with airway inflammation, oxidative stress, and bronchial hyperresponsiveness. The goal of this study was to examine whether these adverse effects of ozone could be prevented or reversed by hydrogen sulfide (H2S) as a reducing agent. The H2S donor sodium (NaHS) (2 mg/kg) or vehicle (PBS) was intraperitoneally injected into mice 1 hour before and after 3-hour ozone (2.5 ppm) or air exposure, and the mice were studied 24 hours later. Preventive and therapeutic treatment with NaHS reduced the ozone-induced increases in the total cells, including neutrophils and macrophages; this treatment also reduced levels of cytokines, including TNF-?, chemokine (C-X-C motif) ligand 1, IL-6, and IL-1? levels in bronchial alveolar lavage fluid; inhibited bronchial hyperresponsiveness; and attenuated ozone-induced increases in total malondialdehyde in bronchoalveolar lavage fluid and decreases in the ratio of reduced glutathione/oxidized glutathione in the lung. Ozone exposure led to decreases in the H2S production rate and in mRNA and protein levels of cystathionine-?-synthetase and cystathionine-?-lyase in the lung. These effects were prevented and reversed by NaHS treatment. Furthermore, NaHS prevented and reversed the phosphorylation of p38 mitogen-activated protein kinase and heat shock protein 27. H2S may have preventive and therapeutic value in the treatment of airway diseases that have an oxidative stress basis. PMID:25010831

  7. Isolation of sulfite reductase variants of a commercial wine yeast with significantly reduced hydrogen sulfide production.

    PubMed

    Cordente, Antonio G; Heinrich, Anthony; Pretorius, Isak S; Swiegers, Jan H

    2009-05-01

    The production of hydrogen sulfide (H(2)S) during fermentation is a common and significant problem in the global wine industry as it imparts undesirable off-flavors at low concentrations. The yeast Saccharomyces cerevisiae plays a crucial role in the production of volatile sulfur compounds in wine. In this respect, H(2)S is a necessary intermediate in the assimilation of sulfur by yeast through the sulfate reduction sequence with the key enzyme being sulfite reductase. In this study, we used a classical mutagenesis method to develop and isolate a series of strains, derived from a commercial diploid wine yeast (PDM), which showed a drastic reduction in H(2)S production in both synthetic and grape juice fermentations. Specific mutations in the MET10 and MET5 genes, which encode the catalytic alpha- and beta-subunits of the sulfite reductase enzyme, respectively, were identified in six of the isolated strains. Fermentations with these strains indicated that, in comparison with the parent strain, H(2)S production was reduced by 50-99%, depending on the strain. Further analysis of the wines made with the selected strains indicated that basic chemical parameters were similar to the parent strain except for total sulfite production, which was much higher in some of the mutant strains. PMID:19236486

  8. Uranium Immobilization by Hydrogen Sulfide Gaseous Treatment under Vadose Zone Conditions

    SciTech Connect

    Zhong, Lirong; Thornton, Edward C.; Deng, Baolin

    2007-01-01

    Immobilization of hexavalent uranium [U(VI)] by hydrogen sulfide (H2S)-treated soil was investigated using laboratory column experiments to assess the potential of applying in situ gaseous reduction (ISGR) under vadose conditions to uranium remediation. Soil from the Hanford Formation in the U. S. Department of Energy (DOE) Hanford Site, Washington was used in this study. The impact of water chemistry and soil treatment on U(VI) immobilization and the role of gas humidity on soil treatment were investigated. Uranium immobilization results revealed that sorption of U(VI) from deionized water was much stronger than sorption from the simulated Hanford ground water. Gas treated soil was shown to have the potential for immobilizing U(VI) from the simulated ground water, however. In addition, soil treatment output indicated that humidity enhanced the soil reduction. In the first 20 pore volumes, the soil treated with moisturized H2S gas can effectively immobilize more than 80% of the mobile U(VI). Remobilization of uranium upon reoxidation of the sediment was relatively insignificant, at least in the short term, apparently owing to the adsorption or incorporation of uranium into poorly crystallized hydrous ferric oxide products.

  9. A comprehensive study on atomic layer deposition of molybdenum sulfide for electrochemical hydrogen evolution.

    PubMed

    Kwon, Do Hyun; Jin, Zhenyu; Shin, Seokhee; Lee, Wook-Seong; Min, Yo-Sep

    2016-03-24

    Atomic layer deposition (ALD) has emerged as an efficient method to design and prepare catalysts with atomic precision. Here, we report a comprehensive study on ALD of molybdenum sulfide (MoSx) for an electrocatalytic hydrogen evolution reaction. By using molybdenum hexacarbonyl and dimethyldisulfide as the precursors of Mo and S, respectively, the MoSx catalysts are grown at 100 °C on porous carbon fiber papers (CFPs). The ALD process results in the growth of particle-like MoSx on the CFP due to the lack of adsorption sites, and its crystallographic structure is a mixture of amorphous and nano-crystalline phases. In order to unveil the intrinsic activity of the ALD-MoSx, the exchange current densities, Tafel slopes, and turnover frequencies of the catalysts grown under various ALD conditions have been investigated by considering the fractional surface coverage of MoSx on the CFP and catalytically-active surface area. In addition, the ALD-MoSx/CFP catalysts exhibit excellent catalytic stability due to the strong adhesion of MoSx on the CFP and the mixed phase. PMID:26973254

  10. Hydrogen sulfide and the probabilities of inhalation through a tympanic membrane defect

    SciTech Connect

    Ronk, R.; White, M.K.

    1985-05-01

    The authors conclude that workers with tympanic membrane defects (perforated eardrums) should not be excluded from working in atmospheres containing concentrations of hydrogen sulfide (H/sub 2/S). Several existing requirements and recommendations exclude workers with perforated eardrums from working in or around H/sub 2/S. Such protective measures stem from the belief that H/sub 2/S can enter the body through the perforation in sufficient measure to compromise the wearer's respiratory protection. However, based on calculations of anticipated leakage of H/sub 2/S for a variety of eustachian tube conditions and in the absence of either medical literature or personal reports documenting H/sub 2/S poisoning due to eardrum perforation, the recommendation for excluding workers with such a condition from working in or around H/sub 2/S is not supported. The anatomy, physiology, and pathology of the eustachian tube are discussed, including the effects such devices as tympanomaxillary shunts might have on contaminant leakage. The National Institute for Occupational Safety and Health (NIOSH) criteria for respirator tests and sources of respirator leakage are examined and NIOSH recommendations for respiratory protection against H/sub 2/S are outlined.

  11. Manure ammonia and hydrogen sulfide emissions from a Western dairy storage basin.

    PubMed

    Grant, Richard H; Boehm, Matthew T

    2015-01-01

    The reporting of ammonia (NH) and hydrogen sulfide (HS) emissions from dairies to the federal government depends on the magnitude of the emissions. However, little is known about their daily NH and HS emissions and what influences those emissions. Emissions of NH and HS from two manure storage basins at a 4400-head western free-stall dairy were measured intermittently over 2 yr. Each basin went through stages of filling, drying, and then removal of the manure during the study period. Emissions were determined using backward Lagrangian Stochastic and vertical radial plume methods. Ammonia emissions ranged from 35 to 59 kg d in one basin and from 86 to 90 kg d in a second basin, corresponding to a range of 7 to 19 g d head. Basin NH emissions were highest during initial filling and when the manure was removed. Mean HS emissions ranged from 5 to 22 kg d (1.1-4.6 g d head). Basin HS emissions were highest when the basin was filling. Crusting of the basin surface reduced NH but not HS emissions. The cessation of basin filling reduced HS but not NH emissions. Air temperature and wind conditions were correlated with NH emissions. Barometric pressure decreases were correlated with episodic HS emissions. The variability in emissions with stage of manure handling and storage and meteorological conditions indicates that determining the maximum daily emissions and the annual emissions from such waste basins requires consideration of each stage in conjunction with the climatic conditions during the stage. PMID:25602327

  12. Vapor ingestion in Centaur liquid-hydrogen tank

    NASA Technical Reports Server (NTRS)

    Symons, E. P.

    1977-01-01

    Vapor ingestion phenomena were investigated using scale models of the Centaur liquid hydrogen tank to determine the height of the free surface of the liquid when vapor is intially ingested into the tank outlet. Data are compared with an analysin and, is general the agreement is very good. Predictions are presented for minimum liquid levels required in the Centaur liquid hydrogen tank in order to prevent vapor ingestion when restarting the engines in space and the quantities of liquid remaining in the tank at vapor ingestion during main engine firing.

  13. Reaction of Hydrogen Sulfide with Disulfide and Sulfenic Acid to Form the Strongly Nucleophilic Persulfide.

    PubMed

    Cuevasanta, Ernesto; Lange, Mike; Bonanata, Jenner; Coitio, E Laura; Ferrer-Sueta, Gerardo; Filipovic, Milos R; Alvarez, Beatriz

    2015-11-01

    Hydrogen sulfide (H2S) is increasingly recognized to modulate physiological processes in mammals through mechanisms that are currently under scrutiny. H2S is not able to react with reduced thiols (RSH). However, H2S, more precisely HS(-), is able to react with oxidized thiol derivatives. We performed a systematic study of the reactivity of HS(-) toward symmetric low molecular weight disulfides (RSSR) and mixed albumin (HSA) disulfides. Correlations with thiol acidity and computational modeling showed that the reaction occurs through a concerted mechanism. Comparison with analogous reactions of thiolates indicated that the intrinsic reactivity of HS(-) is 1 order of magnitude lower than that of thiolates. In addition, H2S is able to react with sulfenic acids (RSOH). The rate constant of the reaction of H2S with the sulfenic acid formed in HSA was determined. Both reactions of H2S with disulfides and sulfenic acids yield persulfides (RSSH), recently identified post-translational modifications. The formation of this derivative in HSA was determined, and the rate constants of its reactions with a reporter disulfide and with peroxynitrite revealed that persulfides are better nucleophiles than thiols, which is consistent with the ? effect. Experiments with cells in culture showed that treatment with hydrogen peroxide enhanced the formation of persulfides. Biological implications are discussed. Our results give light on the mechanisms of persulfide formation and provide quantitative evidence for the high nucleophilicity of these novel derivatives, setting the stage for understanding the contribution of the reactions of H2S with oxidized thiol derivatives to H2S effector processes. PMID:26269587

  14. Product distributions and rate constants for ion-molecule reactions in water, hydrogen sulfide, ammonia, and methane

    NASA Technical Reports Server (NTRS)

    Huntress, W. T., Jr.; Pinizzotto, R. F., Jr.

    1973-01-01

    The thermal energy, bimolecular ion-molecule reactions occurring in gaseous water, hydrogen sulfide, ammonia, and methane have been identified and their rate constants determined using ion cyclotron resonance methods. Absolute rate constants were determined for the disappearance of the primary ions by using the trapped ion method, and product distributions were determined for these reactions by using the cyclotron ejection method. Previous measurements are reviewed and compared with the results using the present methods. The relative rate constants for hydrogen-atom abstraction, proton transfer, and charge transfer are also determined for reactions of the parent ions.

  15. A highly selective on-off-on responsive lanthanide(iii) based probe for recognition of copper and hydrogen sulfide.

    PubMed

    Yip, Yuk-Wang; Law, Ga-Lai; Wong, Wing-Tak

    2016-01-01

    The development of a europium(iii) based probe () for the detection of Cu(ii) ions and hydrogen sulphide is presented. With the addition of Cu(ii) ions, displayed the greatest quenching among the other cations examined. The binding constant was 74 026 ± 2899 M(-1). Once combined with Cu(ii) ions, demonstrated high specificity for hydrogen sulfide compared to other organic and inorganic sulfur compounds. exhibited an on-off-on type luminescence change with the alternate addition of Cu(ii) ions and H2S along with reversible forming-separating of the complex. PMID:26584271

  16. Fractional Consumption of Liquid Hydrogen and Liquid Oxygen During the Space Shuttle Program

    NASA Technical Reports Server (NTRS)

    Partridge, Jonathan K.

    2011-01-01

    The Space Shuttle uses the propellants, liquid hydrogen and liquid oxygen, to meet part of the propulsion requirements from ground to orbit. The Kennedy Space Center procured over 25 million kilograms of liquid hydrogen and over 250 million kilograms of liquid oxygen during the 3D-year Space Shuttle Program. Because of the cryogenic nature of the propellants, approximately 55% of the total purchased liquid hydrogen and 30% of the total purchased liquid oxygen were used in the Space Shuttle Main Engines. The balance of the propellants were vaporized during operations for various purposes. This paper dissects the total consumption of liqUid hydrogen and liqUid oxygen and determines the fraction attributable to each of the various processing and launch operations that occurred during the entire Space Shuttle Program at the Kennedy Space Center.

  17. Liquid composition having ammonia borane and decomposing to form hydrogen and liquid reaction product

    DOEpatents

    Davis, Benjamin L; Rekken, Brian D

    2014-04-01

    Liquid compositions of ammonia borane and a suitably chosen amine borane material were prepared and subjected to conditions suitable for their thermal decomposition in a closed system that resulted in hydrogen and a liquid reaction product.

  18. Hydrogen sulfide as an endogenous regulator of vascular smooth muscle tone in trout.

    PubMed

    Dombkowski, Ryan A; Russell, Michael J; Olson, Kenneth R

    2004-04-01

    Hydrogen sulfide (H(2)S) is an endogenous vasodilator in mammals, but its presence and function in other vertebrates is unknown. We generated H(2)S from NaHS and examined the effects on isolated efferent branchial arteries from steelhead (stEBA) or rainbow (rtEBA) trout. H(2)S concentration was measured colorimetrically (CM) and with ion-selective electrodes (ISE) in rainbow trout plasma. NaHS produced a triphasic response consisting of a relaxation (phase 1), constriction (phase 2), and relaxation (phase 3) in both unstimulated vessels and in stEBA precontracted with carbachol (Carb). Phase 1 and phase 3 in stEBA were decreased and phase 2 increased in unstimulated vessels by K(+)(ATP) channel inhibition (glibenclamide), or a cocktail of inhibitors of cyclooxygenase, lipoxygenase, and cytochrome P-450 (indomethacin, esculetin, and clotrimazole). Inhibition of soluble guanylate cyclase with ODQ o NS-2028 inhibited phase 3 in stEBA, although NaHS decreased cGMP production by tEBA. stEBA phase 2 contractions were partially inhibited by the myosin light chain kinase inhibitor, ML-9, but unaffected by L-type calcium channel inhibition (methoxyverapamil), whereas contraction in tEBA was partially inhibited by nifedipine or removal of extracellular calcium. Phase 3 relaxations were more pronounced in stEBA precontracted with Carb and no epinephrine (NE) than those cont acted by KCl or K(2)SO(4). stEBA phase 2 and phase 3 responses were dose dependent (EC(50) = 1.1 +/- 1.2 x 10(-3) M and 6.7 +/- 0.9 x 10(-5) M, respectively; n = 7). NaHS was also vasoactive in steelhead bulbus arteriosus, celiac mesenteric arteries, and anterior cardinal veins. Rainbow trout plasma sulfide concentration was 4.0 +/- 0.3 x 10(-5) M, n = 4 (CM) and 3.8 +/- 0.4 x 10(-5) M, n = 9 (ISE); similar to phase 3 EC(50). Because NaHS has substantial vasoactive effects at physiological plasma concentrations, we propose that its soluble derivative, H(2)S, is a tonically active endogenous vasoregulator in trout. PMID:15003943

  19. ELECTROCHEMICAL DETERMINATION OF HYDROGEN SULFIDE AT CARBON NANOTUBE MODIFIED ELECTRODES. (R830900)

    EPA Science Inventory

    Carbon nanotube (CNT) modified glassy carbon electrodes exhibiting a strong and stable electrocatalytic response towards sulfide are described. A substantial (400 mV) decrease in the overvoltage of the sulfide oxidation reaction (compared to ordinary carbon electrodes) is...

  20. ELECTROCHEMICAL DETERMINATION OF HYDROGEN SULFIDE AT CARBON NANOTUBE MODIFIED ELECTRODES. (R830900)

    EPA Science Inventory

    Carbon nanotube (CNT) modified glassy carbon electrodes exhibiting a strong and stable electrocatalytic response towards sulfide are described. A substantial (400mV) decrease in the overvoltage of the sulfide oxidation reaction (compared to ordinary carbon electrodes) is...