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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Oxidation of DMS (Dimethyl Sulfide) in Waste Gases by Chlorine Oxidation Followed by Activated Carbon Reductive Adsorption

Chen, Chi-Hsien 08 August 2012 (has links)
Optical-electrical, rendering, paper-making, and sewage treatment plants emit odorous waste gases containing dimethyl sulfide (DMS) as one of the major odorous compounds. For the protection of ambient air quality and prevention of odor complaints, DMS should be eliminated from the gases before venting them into the atmosphere. This study aimed to develop a process for eliminating DMS in the waste gases by introducing an enough amount of chlorine gas to oxidize DMS therein to non-odorous dimethyl sulfone (DMSO2). The vented gas from the oxidation step is then contacted with a bed of granular activated carbon (GAC) to convert the residual chlorine to GAC-adsorbed hydrochloric acid and get a nearly odor-free gas. Both lab-scale and field tests were performed in this study. Results from the lab test indicate that the GAC had only an equilibrium DMS adsorption capacity of 4.30 mg/g GAC with 15-30 ppm DMS and no chlorine in the test gas. With an empty-bed gas-GAC contact time (EBCT) of around 0.49 s and no DMS in the test gas, 42 ppm gaseous chlorine could completely be reduced to HCl and the reduction product adsorbed to the GAC. The GAC had a minimum chlorine elimination capacity of around 110 mg/g GAC. Lab tests also indicate that with a molar Cl2/DMS ratio (R) of around 0.9 and a gas-phase reaction time of 5 s, and an EBCT of 0.58 s, the influent 22 ppm DMS could be removed to below detectable limits. Results from field tests in an optical-electrical wastewater plant show that by the developed process, < 1 ppm DMS in the plant¡¦s waste gas could be treated to an odor-free degree with a chlorine dose of 4-10 ppm.
2

The production and removal of dimethyl sulphide by marine micro-organisms

Mogg, Andrew January 2012 (has links)
No description available.
3

Bacterial generation of the anti-greenhouse gas dimethylsulfide kinetic, spectroscopic, and computational studies of the DMSO reductase system /

Polsinelli, Gregory Anthony, January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 113-119).
4

Quantum chemical studies and kinetics of gas reactions

Sayin, Hasan, McKee, Michael L., January 2006 (has links) (PDF)
Thesis (Ph. D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographical references.
5

Epibiosis of red algae and algal metabolites as settlement inhibitors of the barnacle Balanus improvisus Darwin

Nylund, Göran M. January 1999 (has links)
Thesis (master's)--Göteborg University, 1999. / Title from PDF t.p. (viewed on Sept. 25, 2007). At head of title: Tjärno Marine Biological Laboratory. Includes bibliographical references (p. 13-14).
6

Epibiosis of red algae and algal metabolites as settlement inhibitors of the barnacle Balanus improvisus Darwin

Nylund, Göran M. January 1999 (has links) (PDF)
Thesis (master's)--Göteborg University, 1999. / Title from PDF t.p. (viewed on Sept. 25, 2007). At head of title: Tjärno Marine Biological Laboratory. Includes bibliographical references (p. 13-14).
7

Extrapolations of the flux of dimethylsulfide, carbon monoxide, carbonyl sulfide, and carbon disulfide from the oceans /

Kettle, A. James. January 2000 (has links)
Thesis (Ph. D.)--York University, 2000. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 370-416). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ59143
8

Aqueous phase reaction kinetics of organic sulfur compounds of atmospheric interest

Zhu, Lei. January 2004 (has links) (PDF)
Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2005. / Davis, Douglas, Committee Member ; Huey, Greg, Committee Member ; Nenes, Athanasios, Committee Member ; Weber, Rodney, Committee Member ; Whetten, Robert, Committee Member ; Wine, Paul H., Committee Chair. Includes bibliographical references.
9

Quantifying Carbonyl Sulfide and Other Sulfur-Containing Compounds Over the Santa Barbara Channel

Black, Julia 01 January 2017 (has links)
Carbonyl sulfide (OCS) is emitted to the atmosphere through the outgassing of ocean surface waters. OCS is also the primary source of sulfur-containing compounds in the stratosphere and contributes to the formation of the stratospheric sulfate layer, an essential controller of the radiative balance of the atmosphere. During the 2016 Student Airborne Research Program (SARP), 15 whole air samples were collected on the NASA DC-8 aircraft over the Santa Barbara Channel. Five additional surface samples were taken at various locations along the Santa Barbara Channel. The samples were analyzed using gas chromatography in the Rowland-Blake lab at UC Irvine, and compounds associated with ocean emissions including OCS, dimethyl sulfide (DMS), carbon disulfide (CS2), bromoform (CHBr3), and methyl iodide (CH3I) were examined. Excluding OCS, the vertical distribution of marine tracers that were analyzed showed dilution with increasing altitude. For OCS, the surface samples all exhibited elevated concentrations of OCS in comparison to samples taken from the aircraft, with an average of 666 ± 26 pptv, whereas the average concentration of OCS in the aircraft samples was 581 ± 9 pptv. 2016 Surface samples were compared to surface samples from SARP campaigns between 2009-2015 taken near or within the 2016 study region. The 2009-2015 samples exhibited an average OCS concentration of 526 ± 8 pptv. It is evident that the 2016 surface samples measured higher concentrations of OCS than ever recorded during previous SARP campaigns and in comparison to global averages: 525 ± 17 pptv in the Northern hemisphere and 482 ± 13 pptv in the Southern hemisphere (Sturges et al., 2001). OCS emissions should be measured using surface samples if emission estimates from the ocean are to be evaluated since measurements from the aircraft (500 ft) are not sufficiently capturing surface concentrations. Additionally, OCS enhancements seen in 2016 had never before been detected by surface samples, revealing a potential phenomenon at work causing the elevation during this year’s campaign.
10

Dimethyl sulfoxide (DMSO), activated sludge volume loading and correlation of dimethyl sulfide (DMS) conversion rate

Hsu, Han-yu 07 September 2012 (has links)
Abstract DMSO (dimethyl sulfoxide) has merits of a high boiling point and high solution power to most photo-resistant materials used in semiconductor and LCD (liquid crystal displayers) industries. Wastewaters originated from the industries contain hundreds of grams of DMSO per cubic mater. DMSO is easily decomposed to DMS (dimethyl sulfide) and DMSO2 (dimethyl sulfone) by microorganisms in biological reactors. Malodorous DMS has a relatively low water solubility and can easily emit into the atmosphere thus causes nuisance problems. The fraction of conversion of DMSO to DMS is possibly related to the volumetric DMSO loading (F/V) to an aerobic wastewater treatment pond. This study aimed to investigate the volumetric DMSO loading which minimize the DMS production. Sequencing batch reaction tests indicate that with F/V of less than 0.45 kg DMSO-S/m3.day, there was no DMS detected in the treating mixed liquor and the vented gas from the liquor. It was also observed that with sulfate-S of higher than 0.55 kg/m3 in the mixed liquor which corresponded to F/V of 0.55 kg DMSO-S/m3.day, a high conversion of DMSO to DMS resulted in the system failure.

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