• Journal of Environmental Science International
• /
• v.10 no.4
• /
• pp.287-292
• /
• 2001

A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide($H_2$S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as $H_2S$ oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of $H_2S$ inlet concentration and CBCT(Empty Bed Contact Time) on $H_2S$ elimination. The pressure drop for particles of size range from 5.6 to 10 mm was 14 mm$H_2S$/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under $H_2S$ inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of $15.2{\ell}$/min. $H_2S$ removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of $H_2S$ inlet concentration. When EBCT was reduced to 5.5 sec, $H_2S$ removal efficiency decreased by about 12 percent. The maximum $H_2S$ elimination capacity was determined to be 269g-$H_2S/m^3{\cdot}hr$.

• Journal of Energy Engineering
• /
• v.25 no.1
• /
• pp.171-176
• /
• 2016

Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide ($H_2S$). Natural gas is usually considered sour gas if there are more than 5.7 milligrams of $H_2S$ per cubic meter of natural gas, which is equivalent to approximately 4 ppm by volume under standard temperature and pressure We have surveyed on the treatment and removal technology of sour gas, sour gas include a lot of hydrogen sulfide($H_2S$), Carbon dioxide($CO_2$), utane($C_4H_{10}$) and mercaptan($C_nH_{4n-1}SH$) etc. We need high technology for development for these kinds of raw gases and we should specially take care of treating and removal of theses raw gases. Therefor we are going to describe about these kinds of raw gases and about methods how to treat these kinds of gases.

• Korean Journal of Veterinary Research
• /
• v.55 no.3
• /
• pp.191-197
• /
• 2015

Escherichia (E.) coli is commensal bacteria found in the intestine; however, some pathogenic strains cause diseases in animals and humans. Although E. coli does not typically produce hydrogen sulfide ($H_2S$), $H_2S$-producing strains of E. coli have been identified worldwide. The relationship between virulence and $H_2S$ production has not yet been determined. Therefore, characteristics of $H_2S$-producing isolates obtained from swine feces were evaluated including antibiotic resistance patterns, virulence gene expression, and genetic relatedness. Rates of antibiotic resistance of the $H_2S$-producing E. coli varied according to antibiotic. Only the EAST1 gene was detected as a virulence gene in five $H_2S$-producing E. coli strains. Genes conferring $H_2S$ production were not transmissible although the sseA gene encoding 3-mercaptopyruvate sulfurtransferase was detected in all $H_2S$-producing E. coli strains. Sequences of the sseA gene motif CGSVTA around Cys238 were also identical in all $H_2S$- producing E. coli strains. Diverse genetic relatedness among the isolates was observed by pulsed-field gel electrophoresis analysis. These results suggested that $H_2S$-producing E. coli strains were not derived from a specific clone and $H_2S$ production in E. coli is not associated with virulence genes.

• Journal of Korean Society for Atmospheric Environment
• /
• v.29 no.6
• /
• pp.811-817
• /
• 2013

A two-stage bioreactor system using sulfur-oxidizing bacteria was studied to abate high strength hydrogen sulfide ($H_2S$) from biogas. The two-stage bioreactor consisted of a $H_2S$ absorption column (0.5 L) and a microbial oxidation column (1 L) in series, and the liquid medium was continuously recirculated through the columns. The objectives of this study were to determine the feasibility of the bioreactor for biogas desulfurization and to investigate the effect of the medium circulation rate on the system performance. An averaged concentration of $H_2S$ introduced to the bioreactor was 530 ppm, corresponding to an overall loading rate of $44.4g/m^3/hr$. During the initial 20 days period at the medium recirculation rate of 8 reactor volumes per hour (12 L/hr), the dissolved oxygen (DO) concentration in the oxidation column was 6 mg/L, while the DO in the absorption column was 0.5 mg/L showing that the oxygen contents of the biogas stream was not altered. Because of the biological oxidation of $H_2S$ in the oxidation column, the sulfate concentration increased from 200 mg/L to 5,600 mg/L in the liquid medium. The removal efficiency of $H_2S$ was greater than 99% in the initial operation period. After the initial period, the medium recirculation rate between the two columns was stepwise changed eight times from 1.0 to 40 vol/hr (1.5~60 L/hr). At the recirculation rate of faster than 4 vol/hr, the $H_2S$ removal efficiencies were found to be high, but the efficiency declined at the lower recirculation rates than the threshold.

• Journal of Korean Society of Water and Wastewater
• /
• v.21 no.5
• /
• pp.621-629
• /
• 2007

This study intends to investigate the characteristics of the foul smell of sewer pipes near large apartment complexes as complaints about offensive odors have drastically increased in urban residential areas. Targeting apartments where people actually complained about foul orders, the study result revealed that components in the smell of the water-purifier tank of the target apartment were very similar to those of sewage treatment plants and night soil treatment plants. Measuring components of odors inside the management layer of tank showed that the concentration of hydrogen sulfide was 10ppm, which is approximately 160 times the safety standard of 0.06ppm; the concentration of mercaptan was 0.9ppm, which is about 220 times the safety standard of 0.004ppm. The source materials of foul odors were discharged outside through ducts, and those households living near outlets producing bad smell complain that it gets worse depending on the air pressure or wind direction and strength, and they could not even open windows. As well, these source materials were transferred by discharge pumps to public sewer pipes outside the apartment complex. While discharge pumps starts operating, they remain on the sewer pipe and then begin to spread over to roads through small openings of manholes on the road. Then, the smell offends passers-by and residents near the road, leading to a lot of complaints. The study results suggest that, among the sources of foul odors in sewer pipes of residential areas, especially those from the water-purifier tank of large apartments, hydrogen sulfide should be the main target for follow-up treatment.

• Journal of Environmental Health Sciences
• /
• v.46 no.2
• /
• pp.170-183
• /
• 2020

Objectives: This study was conducted to estimate a technology to reduce hydrogen sulfide (H₂S) in sewage odor using microbial deodorant. Methods: After injecting five commercially available microbial deodorants into fresh sewage, the concentration of hydrogen sulfide over time was measured using the headspace method. H₂S concentration in odor samples was measured using gas chromatograph/FPD. Calculated odor concentration and calculated odor intensity by H₂S concentration remaining after treatment with microbial deodorant were evaluated theoretically. Results: The rate of H₂S abatement by microbial deodorant differed depending on the experimental conditions and the type of deodorant, but it was found to range from 63 to 82%. Especially, two deodorants showed high H₂S reduction rates of over 80% on average. However, based on the best deodorant, the theoretically calculated odor concentration by H₂S after microbial deodorant treatment was 4,400 OU_k, and the theoretical odor intensity was also rated at 4 degrees or higher. Conclusions: In conclusion, microbial deodorant is considered to have a relatively high effect on reducing H₂S in sewage odor. However, even after treatment with microbial deodorant, calculated odor concentration and calculated odor intensity were relatively high. This is thought to be caused by other odorous substances besides H₂S.

• KSBB Journal
• /
• v.9 no.3
• /
• pp.287-293
• /
• 1994

A bacterium isolated from waste coal mine water around Hawsun had an ability for the degradation of hydrogen sulfide. The isolate was identified as Thiobacillus sp. IW. on the basis of its morphological, physiological and chemotaxonomical characteristics. The optimum pH and temperature were 7 and $30^{\circ}C$, respectively. Growth occurred in a pH range of 3 to 9. Due to the sulfate accumulated in liquid medium, the pH decreased. As a consequence the cell growth was inhibited. Potasium nitrate and glutamic acid were utilized as a nitrogen source but urea and ammonium chloride not consumed. Denitrification occurred in a basal medium containing the glucose but did not in a basal medium containing the malate. The maximum specific growth rate of cell was 0.78h-1 and generation time was 0.9 hour. The cell productivity was 6.25mg/1$.$h and the isolate grew logarithmically up to 18 hour. These results indicate that the isolate can be a suitable bacterium responsible for degradation of hydrogen sulfide as malodorous compounds.

• Clean Technology
• /
• v.20 no.4
• /
• pp.406-414
• /
• 2014

Biogas is a gaseous mixture produced from microbial digestion of organic materials in the absence of oxygen. Raw biogas, depending upon organic materials, digestion time and process conditions, contains about 45-75% methane, 30-50% carbon dioxide, 0.3% of hydrogen sulfide gas and fraction of water vapor. To achieve the standard composition of the biogas the treatment techniques like absorption or membrane separation was performed for the resourcing of biogas. In this paper the experimental results of the methane purification in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulfide were presented. The composite membrane is manufactured within polysulfone in order to increase the separation performances for the gaseous mixtures of $CO_2$ and $CH_4$ which are main components of the biogas. The effects of feed pressures and mixed gas on the separation of $CO_2-CH_4$ by membrane are investigated. Chelate chemical was utilized to treat the purification of methane from the $H_2S$ concentration of 0.3%.

• Korean Journal of Microbiology
• /
• v.32 no.4
• /
• pp.252-257
• /
• 1994

A new hydrogen sulfide-oxidation bacterium, Thiobacillus sp. was isolated from waste coal mine water around Hawsun in Chunnam province. The isolate was motile gram-negative rod shape, formed spore and grew up to be aerobically facultative chemolithotroph by using energy released from the oxidation of reduced inorganic sulfur compounds. It could assimilate various kinds of organic compounds and grew well upon thiosulfate-supplemented basal medium. To the lelvel of 32 mM in thiosulfate concentration, thiosulfate in itself was utilized as energy source for growth. However, from those of the higher concentration than 32 mM, thiosulfate functioned specifically as the substrate inhibitor rather than as the energy source. It was found that the optimum thiosulfate concentration for growth was 32 mM. The G+C content of the DNA was 65.0 mol%. The isolate had 16 : 1 + 17$_{cyc}$, 16 : 0 as their major non-hydroxylated cellular fatty acids, 3-OH 12 : 0 as a hydroxylated fatty acid and also contained unidentified $C_{18}$ branched fatty acid. The ubiquinone system in the respiratory chain was Q-9. Based on the physiological and biochemical characteristics, the isolate was assigned to a novel species of the genus Thiobacillus sp. iw.

• The Korean Journal of Physiology and Pharmacology
• /
• v.25 no.6
• /
• pp.593-601
• /
• 2021

Primary cilia on kidney tubular cells play crucial roles in maintaining structure and physiological function. Emerging evidence indicates that the absence of primary cilia, and their length, are associated with kidney diseases. The length of primary cilia in kidney tubular epithelial cells depends, at least in part, on oxidative stress and extracellular signal-regulated kinase 1/2 (ERK) activation. Hydrogen sulfide (H₂S) is involved in antioxidant systems and the ERK signaling pathway. Therefore, in this study, we investigated the role of H₂S in primary cilia elongation and the downstream pathway. In cultured Madin-Darby Canine Kidney cells, the length of primary cilia gradually increased up to 4 days after the cells were grown to confluent monolayers. In addition, the expression of H₂S-producing enzyme increased concomitantly with primary cilia length. Treatment with NaHS, an exogenous H₂S donor, accelerated the elongation of primary cilia whereas DL-propargylglycine (a cystathionine γ-lyase inhibitor) and hydroxylamine (a cystathionine-β-synthase inhibitor) delayed their elongation. NaHS treatment increased ERK activation and Sec10 and Arl13b protein expression, both of which are involved in cilia formation and elongation. Treatment with U0126, an ERK inhibitor, delayed elongation of primary cilia and blocked the effect of NaHS-mediated primary cilia elongation and Sec10 and Arl13b upregulation. Finally, we also found that H₂S accelerated primary cilia elongation after ischemic kidney injury. These results indicate that H₂S lengthens primary cilia through ERK activation and a consequent increase in Sec10 and Arl13b expression, suggesting that H₂S and its downstream targets could be novel molecular targets for regulating primary cilia.