• Title/Summary/Keyword: sulfur oxidation

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A Study on the Photodegradative Behavior of the Dibenzothiophene (DBP) in Water System (수용액중의 디벤조치오펜의 광화학적 분해반응의 연구)

  • Kim, Jae-Hyoun
    • Environmental Analysis Health and Toxicology
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    • v.14 no.3
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    • pp.121-126
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    • 1999
  • The present paper describes a study of the photochemical kinetics and its oxidation mechanism of DBT. The photolysis of DBT in aqueous solution media have shown to have significant oxidation activities for the photolytic desulfurization of DBT. The oxidation effect was more pronounced in 4 % NaCl solution. A mechanism was proposed that the desulfurization process arise from the substution of sulfur by the hydroxyl radicals in different aqueous medium.

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Characteristics of Sulfur oxidation and the Removal of Hydrogen sulfide by Burkholdera[Pseudomonas] cepacia (Burkholderia[Pseudomonas] cepacia의 황 산화 특성 및 황화 수소 제거)

  • 정성제;이은관;전억한;윤인길;박창호
    • KSBB Journal
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    • v.16 no.5
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    • pp.466-473
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    • 2001
  • A bacterium was isolated from soils in Suwon, Korea for the purpose of H$_2$S removal using a biofilter system. The isolate was gram-negative, rod-shaped, catalase-positive, motile, and the isolated bacterium showed a positve in utilizing energy sources including citrate, mannitol, sucrose, fructors, and trehalsoe. Based on its biochemical characteristics it was identified as Burkholderia(Pseudomonas) cepacia. The growth rate of the bacterium in thiosulfate medium with yeast extract was 0.15 hr$\^$-1/ and generation time was 4.6 hr. The cell productivity was 8.05 mg/L$.$h and the isolate grew logarithmically up to 12 hr. The maximum rate of sulfur oxidation was 0.18 g-S/L$.$h. The optimum pH and temperature for the growth of the bacterium were 7.0 and 30$\^{C}$, respectively. The pH range for the growth of B. cepacia was 5.0-8.0. The oxidation rate of thiosulfate was lowered by a substrate thiosulfate when the concentration was higher than 0.12 M. both growth rate and sulfur oxidation rate of Burkholderia(Pseudomonas) cepacia was enhanced about 1.5 times with the addition of 0.2% yeast extract. The removal of hydrogen sulfide was investigated by immobilized B. cepacia with Ca-alginate. The maximum rate removal for H$_2$S was 6.25 g$.$$.$h$\^$-1/ when 12 L/h of flow rate was supplied. From this study suggest the immobilized B. cepacia could have a potential for H$_2$S removal.

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Photochemical Conversions of Reduced Sulfur Compounds to SO2 in Urban Air (도시의 환원 황 화합물의 이산화황으로의 광화학적 변환)

  • Shon, Zang-Ho;Kim, Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.5
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    • pp.647-654
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    • 2004
  • This study examines the local oxidation chemistry of reduced sulfur compounds (RSC) in the urban air. The chemical conversion of RSC (such as DMS, $CS_2,\;H_2S,\;DMDS,\;and\;CH_3SH)\;to\;SO_2$ was modeled using a photochemical box model. For our model prediction of the RSC oxidation, measurements were carried out from an urban monitoring station in Seoul (37.6$^{\circ}$N, 127.0$^{\circ}$E), Korea for three separate time periods (Sep. 17~18; Oct 23; and Oct. 27~28, 2003). The results of our measurements indicated that DMS and $H_2S$ were the dominant RSC with their concentrations of 370${\pm}$140 and 110${\pm}$60 pptv, respectively. The conversion of DMDS to $SO_2$ can occur efficiently in comparison to other RSC, but it is not abundant enough to affect their cycles. The overall results of our study indicate that the photochemical conversion of the RSC can contribute ≶ 20% of the observed $SO_2$.

Oxidation of Tricarbonylmolybdacarborane.3.1 A New Entry to the First Examples of Sulfido-Bridged Dinuclear molybda(V)carboranes

  • Hwang, Jeong-Wook;Kim, Jae-Hak;Kim, Jin-Kwon;Uhm, Jae-Kook;Do, Young-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.23 no.9
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    • pp.1257-1262
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    • 2002
  • $[(C_2B_9H_{11})Mo(CO)_3]_2PPN_2$ $(2{\cdot}PPN_2)$, a new precursor for the oxidative decarbonylation reaction, was synthesized in high yield by the one-electron oxidation reaction of $[(C_2B_9H_{11})Mo(CO)_3]PPN_2$. $2{\cdot}PPN_2$ was structurally characterized, showing a dimeric nature with long (3.321 ${\AA}$) Mo-Mo bonding. Reaction of $2{\cdot}PPN_2$ with sulfur gave the completely decarbonylated product $[(C_2B_9H_{11})Mo({\mu}-S)(S)]_2PPN_2$ ($3{\cdot}PPN_2$). The ligand substitution of the terminal sulfur ligands in $3{\cdot}PPN_2$ to oxygen ligands was carried out with the use of PhIO to give $[(C_2B_9H_{11})Mo({\mu}-S)(O)]_2PPN_2$ ($4{\cdot}PPN_2$). The structures of $3{\cdot}PPN_2$ and $4{\cdot}PPN_2$ were also studied.

Optimization of the Sulfur-oxidzing Bacteria, Thiobacillus novellus SRM (황 산화 세균인 Thiobacillus novellus SRM 성장 최적화)

  • 권규혁;차월석;고한철;이광연;박돈희;차진명
    • KSBB Journal
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    • v.18 no.6
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    • pp.443-447
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    • 2003
  • The microorganism was isolated from the night soil treatment plant for the removal of sulfur compounds. The growth conditions of the sulfur-oxidizing bacteria were investigated and the isolate characterized as Thiobacillus noveilus SRM. The optimal pH of Thiobacillus novellus SRM on cell growth was pH 7.0 and the optimal temperature was 30$^{\circ}C$ and the optimal air flow rate was 1 vvm, respectively. As a results of cell growth from the Monod plot, the specific growth rate was 0.032 hr$\^$-l/, $V_{max}$ was 1.43 hr$\^$-l/ and $K_{m}$ was 0.32, respectively. The thiosulfate oxidation by Thiobacillus novellus SRM was made of sulfate ion. The sulfate ion reduced pH and decreased cell growth.

A Study on Denitrification by Sulfur-Oxidizing Bacteria for the Industrial Wastewater Contain Fluoride and Nitrogen (불소.질소 함유 폐수의 황산화탈질에 관한 연구)

  • Cho, Nam-Chan;Moon, Jong-Han
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.10
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    • pp.774-781
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    • 2011
  • Nitric acid and hydrofluoric acid are used for acid pickling in zirconium alloy tubing manufacturing process. Nitrate and fluoride in the wastewater were treated by chemical coagulation and SOD (Sulfur Oxidation Denitrification) process. This study is investigated the effect of fluoride concentration and the optimal condition for SOD process. The limited fluoride concentration for SOD process was below 20 mg F-/L. The adjusted pH and alkalinity by NaOH and $NaHCO_3$ was shown to be more effective for removal of nitrate compared with using NaOH. Furthermore, the microbial activator mixed trace elements and ingredient for alkalinity did not only supplement with alkalinity but also enhance the growth and proliferation for sulfur-oxidizing bacteria. As a result, the inorganic industrial wastewater was successfully treated by the microbial activator in SOD process without continuous addition of seed sludge. Finally, SOD process was shown to remove nitrate in industrial wastewater and to contribute the microbial activator for activation of sulfur-oxidizing bacteria.

A Study on the Optimization of Fuel Allocation for the Management of Sulfur Dioxide Pollution (亞黃酸가스 汚染度 管理를 위한 燃料配分의 最適化에 관한 硏究)

  • 安徹;金丁勖
    • Journal of Korean Society for Atmospheric Environment
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    • v.2 no.1
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    • pp.103-110
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    • 1986
  • Since sulfur dioxide is released from the oxidation of sulfur in fuel, the level of $SO_2$ in industrial areas can be effectively managed by optimizing the allocation of fuels: the fuel should be allocated to each industries so as to achieve the air quality goal in the area with minimum fuel cost. The solution for this can be by solved using linear programming technique incorporated with the Gaussian dispersion equation. When this method was applied in Ulsan Industrial Complex, 39.3% of fuel expense could be saved compared with the present uniform fuel policy. With this method, bituminous coal generally was allocated to big emission sources such as power plants or to industries sparsely located in remote areas, and LPG or low-sulfur oils to small or medium-size sources in dense indurstrial aras. However, the particulates emission will increase with this policy, because it maximizes the use of coal within the limit to achieve the air quality goal in the area.

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An Experimental Study on SOx and PM Reduction by Sulfur Content in Light Duty Diesel Engine (소형디젤기관에서 황함유량에 따른 SOx 및 PM저감에 관한 실험적 연구)

  • Han, Yeong-Chul;O, Yong-Seok
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.4
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    • pp.387-392
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    • 1998
  • Recently, among after-treatment devices which have high possibility of utility, diesel oxidation catalyst (DOC) is concerned over the world. DOC oxidizes pollutants by means of activate-reaction during by -passing in the catalyst, in doing so, conversion efficiency of PM, CO and HC is high, and this device does not have an effect on engine performance because back pressure is not nearly increased. But, as a small amount of sulfur content in fuel is oxidized, it makes sulfate, which is absorbed on the surface of catalyst. So, in this study, the experiment is carried out by means of using ordinary fuel (0.1wt%) and low sulfur fuel (0.05wt%) with DOC, and the emission gas of diesel engine is measured.

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동위원소를 이용한 폐금속광산 지역 오염원 추적 연구

  • Yeom Seung-Jun;Lee Pyeong-Gu;Lee In-Gyeong;Lee Uk-Jong
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.209-212
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    • 2006
  • Using sulfur sotope analysis of dissolved sulfate in surface water, we have investigated the source of sulfate in order to identify the abandoned metallic mines, which have the potential of heavy metal contamination within watershed. The range of the sulfur isotope values for dissolved sulfate in stream waters (DD-1 and 2) are similar to those of sulfides from the Dunjun mine, which suggests that oxidation of sulfides is the principal source of $SO_4^{2-}$ in these stream waters. Also, heavier sulfur isotopes in waters near Baekjun and Hamchang mines imply the possibility of contamination in waters by these metallic mines.

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The Effect of Oxidation/Reduction of Sulfide Mineral on Its Recovery by Flotation (산화(酸化)/환원(還元) 조건(條件)에 따른 황화광물(黃化鑛物)의 부유선별(浮游選別)에 의한 회수성(回收性) 변화(變化))

  • Kim, Dong-Su
    • Resources Recycling
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    • v.16 no.2 s.76
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    • pp.12-16
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    • 2007
  • The influence of oxidation on the floatability of sulfide minerals contained in mine failings has been investigated employing chalcopyrite as a target material. The critical surface tension of chalcopyrite was estimated to be about 15.5 dyne/cm based on Zisman plot and the floatability of chalcopyrite was observed to increase with the concentration of collector. The enhanced float-ability of chalcopyrite at its initial stage of oxidation was considered to be due to the transformation of disulfide to elemental sulfur and the decrease in its floatability at further oxidation was presumably caused by the formation of sulfate and/or disulfur trioxide from elemental sulfur. When the oxidized chalcopyrite was reduced, its floatability was increased and the variation of the critical surface tension of chalcopyrite according to tile oxidation/reduction was interpreted by an energy diagram constructed by different bond energies between atoms.