scholarly journals Influence of Intermittence and Pressure Differentials in Hydrogen Sulfide Concentration in a Gravity Sewer

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1780 ◽  
Author(s):  
Rita Ventura Matos ◽  
Filipa Ferreira ◽  
José Saldanha Matos
Keyword(s):  
Hydrogen Sulfide ◽  
Pollutant Emissions ◽  
Maximum Pressure ◽  
Normal System ◽  
Sulfide Concentration ◽  
Gas Concentration ◽  
Pumping Stations ◽  
Gravity Sewer ◽  
Operation Pressure

The work presented herein was carried out to assess the effect of intermittent pumping events in sewer headspace pressure differentials, as well as their relationship with hydrogen sulfide gas concentration. A full scale gravity sewer in Portugal, located downstream of several pumping stations, was used as the guiding case study. Under normal system operation, pressure difference between the outside atmosphere and the sewer headspace seemed to influence the in and out-gassing of gas pollutants emitted through the venting stack. Wastewater pumping cycles generated maximum pressure differentials of roughly 100 Pa, which in turn originated maximum air velocities of 1.76 m s−1 exiting the venting stack. Each pumping event was followed by a pressure drop of about 50 Pa, quickly attaining null concentrations of H2S at the venting stack. A statistically significant relationship between pressure differentials and air exit velocity was observed, which allowed obtaining an empirical equation for expedite prediction of airflows emitted to the outside atmosphere (R2 = 0.77). Conversely, the same effect was not observed along the length of the sewer pipe, unlike the findings of other studies. The effect of a full flowing pipe at the downstream end of the gravity trunk sewer was also noticeable in downstream sewer pressurization and gas build-up. It was concluded that the magnitude of the gas pollutant emissions may heavily depend on the impacts of hydraulic flows and pumping characteristics in headspace pressure differences, denoting the need for better approaches when designing and installing venting stacks.

scholarly journals PSIX-9 Impacts of bunk management on feedlot performance, carcass characteristics, hydrogen sulfide concentration and blood oxygen saturation in steers fed 25 or 50% modified distillers grains plus solubles

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 422-422
Author(s):  
Rebecca L Moore ◽  
Cierrah J Kassetas ◽  
Leslie A LeKatz ◽  
Bryan W Neville
Keyword(s):  
Hydrogen Sulfide ◽  
Oxygen Saturation ◽  
Management Strategy ◽  
Distillers Grains ◽  
Feed Ratio ◽  
Sulfide Concentration ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Feedlot Performance ◽  
Arterial Blood

Abstract One hundred and twenty-six yearling angus steers (initial body weight 445.87 ± 7.13 kg) were utilized in a 2 x 2 factorial design to evaluate the impacts of bunk management and modified distillers grains plus solubles (mDGS) inclusion on feedlot performance, hydrogen sulfide concentrations and blood oxygen saturation. Treatments included bunk management strategy either control bunk management (CON; clean bunks at the time of next day’s feeding) or long bunk management (LONG; feed remaining at time of next day’s feeding), and two inclusion rates of mDGS either 25% or 50% (DM Basis). On d 0, 7, 14, 21, 28 and 35 rumen gas samples were collected via rumenocentesis, and arterial blood samples were collected on two steers from each pen. No differences (P ≥ 0.09) were observed for dry matter intake, average daily gain and gain-to-feed ratio for bunk management or mDGS inclusion. Hot carcass weight, ribeye area, marbling score and quality grade were not affected (P ≥ 0.48) by either bunk management or mDGS inclusion. Back fat was greater (P = 0.04) for CON steers compared to LONG (1.30 vs 1.12 ± 0.05cm, respectively), but was not affected (P = 0.59) by mDGS inclusion. Steers on CON had greater (P = 0.03) yield grades compared to LONG (3.21 vs 2.96 ± 0.11, respectively). Bunk management strategy did not impact hydrogen sulfide concentrations or blood oxygen saturation (P = 0.82). Hydrogen sulfide concentrations increased (P < 0.001) with increasing mDGS inclusion. Blood oxygen saturation was influenced by day of sampling (P = 0.01). Blood oxygen saturation was not affected (P = 0.07) by mDGS inclusion. The fact that ruminal hydrogen sulfide concentrations increased while blood oxygen saturation remained similar raises questions about the quantity of hydrogen sulfide and metabolic fate of excess hydrogen sulfide in the blood of ruminant animals.

Roots as a site of hydrogen sulfide uptake in the hydrocarbon seep vestimentiferan Lamellibrachia sp

1999 ◽  
Vol 202 (17) ◽  
pp. 2245-2257 ◽  
Author(s):  
D. Julian ◽  
F. Gaill ◽  
E. Wood ◽  
A.J. Arp ◽  
C.R. Fisher
Keyword(s):  
Hydrogen Sulfide ◽  
Total Mass ◽  
Sea Water ◽  
Tube Wall ◽  
Structural Characteristics ◽  
Sulfide Oxidation ◽  
Sulfide Concentration ◽  
Hydrocarbon Seep ◽  
Respiratory Organ ◽  
Root Tube

Vestimentiferan tubeworms have no mouth or gut, and the majority of their nutritional requirements are provided by endosymbiotic bacteria that utilize hydrogen sulfide oxidation to fix CO(2) into organic molecules. It has been assumed that all vestimentiferans obtain the sulfide, O(2) and CO(2) needed by the bacteria across the plume (gill) surface, but some live in locations where very little sulfide is available in the sea water surrounding the plume. We propose that at least some of these vestimentiferans can grow a posterior extension of their body and tube down into the sea-floor sediment, and that they can use this extension, which we call the ‘root’, to take up sulfide directly from the interstitial water. In this study of the vestimentiferan Lamellibrachia sp., found at hydrocarbon seeps in the Gulf of Mexico at depths of approximately 700 m, we measured seawater and interstitial sulfide concentrations in the hydrocarbon seep habitat, determined the structural characteristics of the root tube using transmission electron microscopy, characterized the biochemical composition of the tube wall, and measured the sulfide permeability of the root tube. We found that, while the sulfide concentration is less than 1 (μ)mol l(−)(1) in the sea water surrounding the gills, it can be over 1.5 mmol l(−)(1) at a depth of 10–25 cm in sediment beneath tubeworm bushes. The root tube is composed primarily of giant (β)-chitin crystallites (12–30 % of total mass) embedded in a protein matrix (50 % of total mass). Root tubes have a mean diameter of 1.4 mm, a mean wall thickness of 70 (μ)m and can be over 20 cm long. The tubeworm itself typically extends its body to the distal tip of the root tube. The root tube wall was quite permeable to sulfide, having a permeability coefficient at 20 degrees C of 0. 41×10(−)(3)cm s(−)(1), with root tube being 2.5 times more permeable to sulfide than trunk tube of the same diameter. The characteristics of the root suggest that it reaches down to the higher sulfide levels present in the deeper sediment and that it functions to increase the surface area available for sulfide uptake in a manner analogous to a respiratory organ.

scholarly journals Effect of abiotic factors on sulfidogenic activity of bacteria Desulfuromonas sp.

2020 ◽  
Vol 11 (2) ◽  
pp. 170-174
Author(s):  
O. M. Сhaіka ◽  
T. B. Peretyatko
Keyword(s):  
Hydrogen Sulfide ◽  
Cell Density ◽  
Elemental Sulfur ◽  
Abiotic Factors ◽  
Electron Acceptors ◽  
Stress Factors ◽  
Sulfide Concentration ◽  
Sulfur Concentration ◽  
Reducing Bacteria ◽  
Hydrogen Sulfide Concentration

Sulfur-reducing bacteria are promising agents for the development of new methods of wastewater treatment with the removal of ions of heavy metals and organic compounds. Study of the effect of various environmental factors on the growth and sulfidogenic activity of sulfur-reducing bacteria allows one to investigate the adaptability of these microorganisms to stress factors. The paper deals with the effect of рН, different concentrations of elemental sulfur, hydrogen sulfide and presence of various electron acceptors on the growth and sulfidogenic activity of bacteria Desulfuromonas sp. YSDS-3. The calculation of C/S ratio for sulfur-reducing bacteria Desulfuromonas sp. YSDS-3 was made, with the comparison with similar parameters of sulfate-reducing bacteria. In the medium with elemental sulfur, concentration of hydrogen sulfide increased with the concentration of elemental sulfur. Bacteria Desulfuromonas sp. YSDS-3 accumulated their biomass in the most effective way at the concentration of elemental sulfur of 10–100 mM. In the medium with polysulfide form of sulfur at the neutral pH, bacteria produced hydrogen sulfide and accumulated biomass the best. Hydrogen sulfide at the concentration of 3 mM did not inhibit the bacterial growth, but further increase in the hydrogen sulfide concentration inhibited the growth of bacteria. The bacteria did not grow at the hydrogen sulfide concentration of 25 mM and above. As the concentration of elemental sulfur and cell density increases, sulfidogenic activity of the bacteria grows. Presence of two electron acceptors (S and K2Cr2O7, S and MnO2, S and Fe (III)) did not affect the accumulation of biomass of the bacteria Desulfuromonas sp. YSDS-3. However, under such conditions the bacteria accumulated 1.5–2.5 times less hydrogen sulfide than in the test medium. After 12–24 h of cultivation, different concentrations of elemental sulfur had a significant effect on the sulfidogenic activity. However, during 3–16 days of cultivation, the percentage of effect of elemental sulfur concentration decreased to 31%, while the percentage of effect of cell density increased threefold. Presence in the medium of the electron acceptors (Cr (VI), MnO2, Fe (III)) alternative to elemental sulfur led to a significant decrease in the content of hydrogen sulfide produced by sulfur-reducing bacteria.

scholarly journals Occupational inhalation injury by Hydrogen Sulfide causing multi organ failure –A case study

2019 ◽  
Vol 7 (2) ◽  
pp. 113-115 ◽  
Author(s):  
Karishma Shamarukh ◽  
- Mohammad Omar Faruq ◽  
Nasrin Jahan ◽  
Amina Sultana ◽  
Ridwan Naim Faruq
Keyword(s):  
Hydrogen Sulfide ◽  
Troponin I ◽  
Treatment Plant ◽  
Inhalation Injury ◽  
Effluent Treatment ◽  
Effluent Treatment Plant ◽  
Chest X Ray ◽  
Brain Ct Scan ◽  
Serious Injuries

Hydrogen sulfide is a notorious agent known to cause serious injuries in the occupational field. We are going to discussa case of a 20 years old male working in a effluent treatment plant in Savar, Bangladesh who accidentally entered thefume room and was exposed to the toxic gas. He lost consciousness and was brought to our care from a local hospitalafter endotracheal intubation condition. He was found in state of unconsciousness grade III on admission to our ICU.His brain CT scan revealed diffuse cerebral edema. Chest X-ray revealed finding suggestive of diffuse pneumonitis.Cardiology evaluation suggested Toxic cardiomyopathy as his high sensitive Troponin I was very high on admission (2037ng/L). Supportive care was given in the form of mechanical ventilation, antibiotics, anticonvulsant andanti-ischemic medications. Patient regained consciousness on day 10 after admission and gradually improvedclinically. By the end of the month of stay in hospital he was significantly improved. Bangladesh Crit Care J September 2019; 7(2): 113-115

scholarly journals Problems of Mechanized Tunneling In Gassy Ground Conditions a Case Study: Nousoud Water Transmission Tunnel

2014 ◽  
Vol 3 (8) ◽  
pp. 101-113
Author(s):  
Naser Tali ◽  
Gholam Reza Lashkaripour ◽  
Mohamad Ghafoori ◽  
Naser Hafezimoghadas
Keyword(s):  
Hydrogen Sulfide ◽  
Dissolved Gas ◽  
Loss Of Life ◽  
Methane Gas ◽  
Project Costs ◽  
Ground Conditions ◽  
Water Transmission ◽  
Working Efficiency ◽  
Geotechnical Studies

Current advances in science, followed by development of excavation equipments technology resulted in growth of tunnelling projects for different purposes. In spite of conducting exploratory studies prior to these projects, in some cases due to of impassable paths, the studies are limited to certain areas. Hence, during geotechnical studies, it is possible that all problems facing tunnelling not be detected. Therefore, lack of awareness of these conditions can result in a lack of proper planning and consequently lead to problems during the projects. Due to the lack of knowledge and consequently not predicting and planning the projects, drilling of the second sector of Nousoud water transmission tunnel, -26 km long- has been faced with many problems including emission of hydrogen sulfide and methane gas and drainage of high volumes of water containing dissolved gas into the tunnel, which has led to the loss of life, loss of working efficiency, as well as increased project costs. In this study, problems occurred in this project, reasons behind them will be addressed; and the solutions to these problems will be mentioned. The results of the study have shown that oil-bearing formations of the region and the immigration of gases coming from these formations have let the gas entered into the tunnel. In addition, due to the high solubility of hydrogen sulfide and methane gas in water on one hand, and hydrated formations with high permeability on the other hand, caused the influx of large quantities of water and therefore the concentration of these gases in the tunnel.

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