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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.
21

Use of Manganese Compounds and Microbial Fuel Cells in Wastewater Treatment.

Jiang, Junli January 2011 (has links)
Manganese compounds have a high potential for treating wastewater, both for utilizing its oxidation, flocculation ability and catalyst ability in anaerobic nitrification. The promising use of manganese compounds (such as permanganate and manganese dioxide) is regarded as an effective method of treating organic compounds in wastewater from municipal and industrial wastewater. Now it is newly realized possibilities to combine manganese compounds with Microbial Fuel Cell technology. Aiming at reusing the biomass in anaerobic digested sludge for degrading organic pollutants and simultaneously recovering electric energy, Single-chamber Microbial Fuel Cell (SMFC) system was developed and investigated during the main experimental part. Considering the electricity generation rate and characteristics of cathode, MnO2 was used as the reactant on the cathode electrode; meanwhile, the substrate types in anode compartment also were investigated and then extra sodium acetate was added to investigate the power generation performance. Two parts of the research were carried out during the whole project. The chemical treatment part was mainly designed to find out the best dosage of KMnO4 in flocculation when concurrent reacted with magnesium and calcium compounds when treating reject wastewater from digester at Hammarby Sjöstadsverk. The other part was studied to see whether it is possible to improve electricity generation by degrading organic pollutants when MnO2 was used as a cathodic reactant in sediment microbial fuel cell which consisted of anaerobic digested sludge from UASB.
22

Impact of Growth Conditions, pH, and Suspension Time on Toxin Release from Microcystis Aeruginosa Upon Exposure to Potassium Permanganate

Roland, David January 2018 (has links)
No description available.
23

Study of the Formation and Control of Disinfection By-Products Originating from a Surface Water Supply on the Volcanic Island of Guam

LaBerge, Erica 01 January 2014 (has links)
Three oxidants have been evaluated for use as alternative chemical pretreatments for Fena Lake, a surface water that supplies the U.S. Navy's Public Water System (PWS) on the volcanic island of Guam. The study consisted of two investigative components. The first and primary component included a bench-scale evaluation to study the effects of different pre-oxidant chemicals on the formation of chlorinated disinfection by-products (DBPs). The second and ancillary component included a series of water treatment and distribution system management studies that analyzed DBP formation within the treatment plant and water distribution system. The goal of this research was to reduce total trihalomethane (TTHM) and the five haloacetic acid (HAA5) formations in the PWS. In the primary component of the research, raw surface water from Fena Lake was collected by U.S. Navy personnel and shipped to University of Central Florida (UCF) laboratories for experimentation. Bench-scale tests that simulated the coagulation, flocculation, sedimentation and filtration (CSF) that comprises the Navy Water Treatment Plant (NWTP) were used to evaluate the use of two alternative pre-oxidants, potassium permanganate (KMnO4) and chlorine dioxide (ClO2) in lieu of gaseous chlorine (Cl2). The research assessed DBP formation by comparing several pretreatment scenarios, namely: (1) no pretreatment, (2) chlorine pretreatment, and (3) alternative oxidant pretreatment. KMnO4 pretreatment resulted in the lowest percent reduction of TTHMs and HAA5 relative to chlorine pretreatment, at 5.7% and 22.7%, respectively; however, this amount was still a reduction from the results demonstrated for the chlorine pretreatment condition. Without using a pre-oxidant, TTHM and HAA5 formation were reduced by 22.8% and 37.3%, respectively, relative to chlorine pretreatment. Chlorine dioxide demonstrated the greatest TTHM and HAA5 reduction relative to chlorine pretreatment at 34.4% and 53.3%, respectively. The second component of research consisted of a series of studies that evaluated distribution system operations and management alternatives to identify opportunities that could achieve DBP reduction within the PWS. Three concerns that were addressed were the NWTP's compliance with the U.S. Environmental Protection Agency's (USEPA's) Stage 2 Disinfectants/Disinfection By-Products (D/DBP) Rule, variable hydraulic detention times within a small subdivision in the distribution system, and severe weather. It was determined that: (1) A decision based on in-plant studies to cease prechlorination at the NWTP resulted in a decrease in TTHMs and HAA5s throughout the distribution system by 62% and 75%, respectively; (2) A fluoride tracer study led to the discovery of a valved pipeline responsible for elevated DBPs because of excessive water age that when exercised and managed resolved intermittent DBP spikes in the PWS; and (3) when the NWTP's ballasted floc clarifier (BFC) was operated in-series prior to the conventional CSF process during severe weather conditions the TTHM and HAA5 were below 39 ug/L and 29 ug/L, respectively, proving BFC in-series is a practical option for the plant during severe weather.
24

An investigation of the oxidative potential of potassium permanganate and chlorine dioxide during the oxidation of reduced manganese

Hair, David Hayne 17 November 2012 (has links)
This project determined the thermodynamic potentials for various reactions between reduced manganese (Mn²), manganese oxide (MnO₂(s)), chlorine dioxide (Cl0₂), and potassium permanganate (KMnO₄). Based on these findings, laboratory analyses were performed to determine if these reactions would occur under simulated water treatment plant conditions. In addition, a speciation procedure was developed to quantify the various species of manganese and chlorine dioxide present in a single sample. The reactions and the speciation procedure were evaluated at TOC concentrations ranging from < 1.0 mg/L to 5.0 mg/L and at pH 6.0 and 8.0. The speciation procedure yielded a reliable measure of Mn², insoluble manganese, and Mn⁺⁷; however, the Mn⁺⁷ evaluation could be disrupted by the presence of free chlorine. The determination of Cl0₂ and Cl0₂- concentrations was also possible; however, the C10₂- concentration was subject to error. The laboratory analyses revealed that Cl0₂ was unable to oxidize either Mn² or MnO₂(s) to Mn⁺⁷ under any of the thermodynamically favored conditions. Both KMn0₄ and Cl0₂ selectively oxidized reduced organic material before reducing the concentration of Mn². When C10₂ and KMnO₄ were added simultaneously, the ClO2 reacted preferentially with the reduced materials. Only after the Cl0₂ concentration was exhausted did the MnO₂⁻ begin to oxidize the reduced species. / Master of Science
25

Treatment of algae-induced tastes and odors by chlorine, chlorine dioxide and permanganate

Buffin, Lisa Webster 11 May 2010 (has links)
Chlorine (Cl₂(sq»' chlorine dioxide (ClO₂ ) and potassium permanganate (KMnO₄) were evaluated as oxidants for the removal of grassy and cucumber odors associated with the pure compounds, cis-3-hexenol and trans-2, cis-6-nonadienal, respectively, and for the removal of fishy odors associated with a culture of an alga, Synura petersenii. The effects of the oxidants on the pure compounds were assessed both by Flavor Profile Analysis (FPA) and gas chromatography/mass spectrometry (GC/MS). The effects of the oxidants on the algae culture were evaluated by FPA only. In addition, an unoxidized sample of Synura petersenii was analyzed by gas chromatography coupled with mass spectrometry (GC/MS) for possible identification of fishy-smelling compounds. Chlorine (1-6 mg/L) and KMn04 (0.25-4 mg/L) markedly reduced grassy and cucumber odors associated with the two compounds. Gas chromatography/mass spectrometry confirmed that these compounds were reduced to below method detection limits. Levels of Cl₂(&q) required (up to 6 mg/L) to reduce the grassy odors associated with cis-3-hexenol were higher than those of KMnO₄ â ¢ The high Cl₂(&q) doses may have contributed to the formation of chemical odors observed by panelists. Two isomers of chlorohexenol were confidently identified as byproducts of cis-3-hexenol chlorination and may have contributed to the chemical odors that developed after CI2(aq) treatment. Chlorine and KMnO₄ (both at 10 mg/L) either reduced or destroyed the fishy odor associated with the culture of Synura petersenii; however, oxidation caused either the development or unmasking of fruity, cucumber, melon and grassy odors. Chlorine dioxide (3 mg/L) did not reduce the grassy and cucumber odors associated with cis-3-hexenol and trans-2, cis-6-nonadienal , respectively. Gas chromatography and mass spectrometry confirmed that concentrations of these compounds were not reduced to below method detection limits. Furthermore, at a concentration of 10 mg/L, Cl₂ did not effectively reduce either the fishy or other objectionable odors associated with Synura petersenii culture. Hexanal, with an odor described as "green" or "like lettuce heart," and trans-2, cis-6-nonadienal (cucumber odor) were confirmed as algal products in a two-week-old culture of Synura petersenii. In addition, decatrienal was confidently identified as a product of Synura and may have contributed to the fishy odor associated with this alga. / Master of Science
26

Design of new activated carbon based adsorbents for improved desulfurization of heavy gas oil: Experiments and kinetic modeling

Nawaf, A.T., Jarullah, A.T., Hameed, S.A., Mujtaba, Iqbal 31 March 2022 (has links)
Yes / In this work, adsorption desulfurization is considered for making cleaner fuel. New efficient adsorbents have been designed by using two active metal oxides mainly potassium permanganate (KMnO4) and potassium phosphate (KPO4·3H2O) on Activated Carbon (AC). Ultrasonic assisted impregnation method (IWI) is used in designing the adsorbents offering high pore volume, pore size, surface chemistry, and high surface area. Use of ultrasonic method increases the dispersion of the active material (groups) on AC leading to increased number of collisions between O-atom on AC-support resulting in high sulfur removal from fuel. KMnO4 on AC shows higher adsorption capacity towards sulfur than KPO4·3H2O at the same operating conditions. New results with respect to sulfur removal has obtained compared with those obtained by previous studies. Finally, the adsorption kinetic parameters of such process are developed. Thomas and Yoon-Nelson models and the experimental data are used for this purpose using linear and non-linear regression analysis. Yoon-Nelson kinetic model fits well with the experiments data better than Thomas kinetic model in the entire adsorption column system.
27

Reactivity studies of arene-cis-diols in cycloadditions and potassium permanganate oxidations: synthesis of the corresponding arene-trans-diols and an approach to the synthesis of (+)-pancratistatin

McKibben, Bryan P. 06 June 2008 (has links)
Potassium permanganate oxidations and novel cycloaddition chemistry of the arene-cis-diols (7) were investigated. It was found that permanganate oxidation of arene-cis-diols yielded a mixture of 2 products, (157a) and (157b) in low yield. The influence of the C1-substituent on the outcome of the reaction was found to be a complex mixture of steric and electronic effects. In the area of cycloaddition chemistry of protected (7), this thesis describes novel [4+2] cycloadditions with quinones along with the first published report of benzyne and nitrile oxide cycloadditions of these homochiral molecules. The structure of the cycloadducts were elucidated by nOe as well as 2D-NMR analysis and were supported by Frontier Molecular Orbital theory. Finally, arene-trans-diols (200) were synthesized from (7) by a multistep stereoselective protection/deprotection sequence utilizing the Diels-Alder reaction. These compounds serve as intermediates in an approach to the amaryllidaceae alkaloid (+)-pancratistatin (12). / Ph. D.
28

Interferência da aplicação do permanganato de potássio conjuntamente ao carvão ativado em pó para a remoção de MIB e Geosmina em águas de abastecimento. / Effect of potassium permanganate on the removal of MIB and geosmin from drinking water by powdered activated carbon.

Andrade, Tássia Brito 17 August 2018 (has links)
MIB e Geosmina são os principais agentes causadores de gosto e odor em águas de abastecimento. O carvão ativado em pó (CAP) desempenha um ótimo papel na remoção de MIB e Geosmina, entretanto, estudos tem comprovado que sua capacidade de adsorção é consideravelmente prejudicada quando em contato com concentrações residuais de agentes oxidantes empregados na etapa de pré-oxidação. Com o objetivo de avaliar o efeito da presença de permanganato de potássio na fase líquida no processo de adsorção de MIB e Geosmina pelo CAP, este estudo foi desenvolvido combinando diferentes dosagens do agente oxidante (zero, 1 e 2 mg L-1 ) e CAP (20 e 40 mg L-1) visando a remoção de MIB e Geosmina. Observou-se uma redução nas concentrações residuais do permanganato de potássio na água, o que evidencia a existência de uma interação entre o agente oxidante e o CAP. A utilização do permanganato de potássio conjuntamente ao CAP mostrou-se prejudicial à remoção de MIB e Geosmina sendo que para a aplicação de 20 mg L-1 de CAP, a presença de 2 mg L-1 de agente oxidante na fase líquida provocou uma redução na remoção de MIB e Geosmina de cerca de 50%. A presença do permanganato de potássio na água, no entanto, não provocou alteração no tempo de contato necessário para a adsorção dos micropoluentes estudados no CAP. Fica evidente, portanto, a necessidade do controle da dosagem do agente oxidante a ser aplicado a fim de se evitar concentrações residuais que possam interagir com o CAP reduzindo sua capacidade de remoção de MIB e Geosmina. / MIB and Geosmin are the main agents causing taste and odor in domestic water supply. Powdered activated carbon (PAC) plays an important role in the removal of MIB and Geosmin, however, studies have shown that its adsorption capacity is considerably impaired when in contact with residual concentrations of oxidizing agents used in the pre-oxidation stage. This study evaluated the effect of adding potassium permanganate in the liquid phase during the adsorption of MIB and Geosmin to PAC. The removal of MIB and Geosmin was evaluated with different dosages of the oxidizing agent, potassium permanganate (zero, 1 and 2 mg L-1) and PAC (20 and 40 mg L-1). The results showed a reduction in the residual permanganate in water, indicating an interaction between the oxidizing agent and the PAC. The use of potassium permanganate together with PAC reduced the MIB and Geosmin removal. The addition of 20 mg L-1 of PAC, in the presence of 2 mg L-1 of oxidizing agent in the liquid phase reduced the removal of MIB and Geosmin by 50%. The contact time required for the adsorption of the micropollutants to PAC, however, was not affected by the presence of potassium permanganate in the water. Therefore, the need to control the oxidizing agent\'s dosage is evident. Dosage control of the oxidizing agent can reduce its residual concentrations, which may interact with the PAC reducing its ability to remove MIB and Geosmin.
29

EFEITOS DA OXIDAÇÃO INDUZIDA COM PERMANGANATO DE POTÁSSIO NA MODIFICAÇÃO DO AMIDO DE PINHÃO

Lazzarotto, Simone Rosa da Silveira 04 March 2016 (has links)
Made available in DSpace on 2017-07-21T18:53:06Z (GMT). No. of bitstreams: 1 Simone Rosa da Silveira Lazzarotto.pdf: 1687996 bytes, checksum: 6af491e1aaa6d51c6be5d21a623c4dc9 (MD5) Previous issue date: 2016-03-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Starch is the main constituent of many plants, widely used in paper, textile, pharmaceutical and food industries. The Araucaria angustifolia, a Brazilian native conifer, there is seeds known as "pinhões" with high starch content. The aim of this study was to modify the “pinhão” starches with different concentrations of potassium permanganate (KMnO4) solutions. The samples were characterized by Thermogravimetry (TG-DTA), Differential Scanning Calorimetry (DSC), Viscoamilografic Analysis (RVA), X-Ray Diffraction, Scanning Electron Microscopy (SEM) and colorimetry. In the TG-DTA curves with synthetic air were observed three mass loss in the samples. In this analysis were changes in the peak temperature and the intensity of thermal events of samples, where in the sample (3) of the “pinhão” starch treated with a concentration of 0.005 mol L-1 KMnO4 were more evident due to consecutive reactions. In the same analysis, but in nitrogen atmosphere, the samples showed two endothermic events of masses losses and only the sample (3) had a last exothermic event of mass loss indicative of the largest oxygen index. The DSC analyzes showed a reduction in gelatinization enthalpy values of all treated samples. These same samples showed less retrogradation tendency (setback) and lower viscosity compared with the native sample in the pasta property analysis (RVA). The X-ray diffraction of the native and treated samples showed similar profiles to the starches A - type pattern. The micrography obtained by SEM showed no significant changes regarding to the diameter and starches granules shape after modification. Through reflectance spectroscopy was showed color change for modified starch samples due to darkening caused by KMnO4.These results showed that the properties of the “pinhão” starches were changed by oxidative action of KMnO4 and future applications will be studied. / O amido é o principal constituinte de diversas plantas, amplamente utilizado em indústrias de papel, têxtil, farmacêutica, e alimentos. A Araucaria angustifolia, uma conífera nativa brasileira, possui sementes conhecidas como “pinhões” com alto teor amiláceo. O objetivo deste estudo foi modificar amidos de pinhão com soluções de diferentes concentrações de permanganato de potássio (KMnO4). As amostras foram caracterizadas por Termogravimetria (TG-DTA), Calorimetria Exploratória Diferencial (DSC), Análise Viscoamilográfica (RVA), Difratometria de Raios X, Microscopia Eletrônica de Varredura (MEV) e colorimetria. Nas curvas TG-DTA com ar sintético foram observadas três perdas de massas nas amostras. Nesta análise houve alterações nas temperaturas de pico e nas intensidades dos eventos térmicos das amostras, sendo que na amostra (3) de amido de pinhão tratado com a concentração de 0,005 mol L-1 de KMnO4, foram mais evidentes devido às reações consecutivas. Na mesma análise realizada em atmosfera de nitrogênio as amostras apresentaram dois eventos endotérmicos de perdas de massas e apenas a amostra (3) apresentou um último evento de perda de massas exotérmico indicativo do maior índice de oxigênio. Nas análises de DSC observou-se uma redução nos valores de entalpia de gelatinização das amostras tratadas. Estas mesmas amostras apresentaram menor tendência a retrogradação (setback) e menor viscosidade, em comparação com a amostra nativa nas análises de propriedade de pasta (RVA). Os difratogramas de raios X das amostras nativa e tratadas mostraram perfis semelhantes ao padrão tipo “A” de amidos. As micrografias obtidas no MEV indicaram que não houve mudanças significativas no diâmetro e na forma dos grânulos de amido após a modificação. Através da espectroscopia de reflectancia foi observada alteração de cor para as amostras de amido modificadas devido ao escurecimento provocado pelo KMnO4. Estes resultados demonstram que as propriedades dos amidos de pinhão foram alteradas pela ação oxidativa do KMnO4 e futuras aplicações poderão ser estudadas.
30

Avaliação da formação de trialometanos considerando o uso de cloro e permanganato de potássio como pré-oxidantes em águas de abastecimento / Evaluation of Formation of Trihalomethanes considering the Use of Chlorine and potassium permanganate as pre-oxidants in drinking water supplies

Agrizzi, Alexandre Demo 25 February 2011 (has links)
Made available in DSpace on 2016-12-23T14:04:32Z (GMT). No. of bitstreams: 1 Alexandre Demo Agrizzi.pdf: 7003943 bytes, checksum: 32fa12e406ceb8e9b8ef241ea1ee79ed (MD5) Previous issue date: 2011-02-25 / O cloro tem sido utilizado como principal pré-oxidante da matéria orgânica, inativando microrganismos patogênicos que vivem em águas naturais há mais de cem anos. A matéria orgânica encontrada em mananciais superficiais contém substâncias húmicas que podem reagir com o cloro, gerando compostos orgânicos halogenados potencialmente cancerígenos, destacando-se os trialometanos. Os principais trialometanos que se formam são o clorofórmio, o bromodiclorometano, o dibromoclorometano e o bromofórmio, e, a soma das concentrações destes quatro subprodutos é denominada trialometanos totais. Nas estações de tratamento de água (ETAs), a etapa de pré-oxidação com o cloro contribui significativamente para a formação desses compostos. A presente pesquisa teve como objetivo avaliar a formação de trialometanos após o tratamento convencional de água a partir da simulação de quatro rotas distintas em ensaios de bancada (jarteste), além de amostras retiradas diretamente das ETAs envolvidas no estudo. Os trialometanos foram quantificados por cromatografia gasosa com detector de captura de elétrons. Foram coletadas amostras de água bruta de dois mananciais do estado do Espírito Santo (Rio Jucu e Rio Sahy), com cor, absorvância em 254 nm e turbidez diferentes. Foram testados dois oxidantes nas análises: o cloro (na forma de hipoclorito de cálcio) e o permanganato de potássio. Os resultados obtidos mostraram que a formação de trialometanos foi menor quando as amostras de água foram tratadas com permanganato de potássio na etapa de pré-oxidação, quando comparadas com as amostras tratadas com cloro. Resultado semelhante ocorreu no potencial de formação de trialometanos de 24 horas. Em relação ao potencial de formação de sete dias, ambos mananciais mostraram ser capazes de formar compostos precursores dos trialometanos. Concentrações de trialometanos acima do limite permitido pela Portaria do Ministério da Saúde nº 518 (2004) foram detectadas somente nas amostras de água tratada do Rio Sahy / Chlorine has been used as the main pre-oxidation of organic matter, inactivating pathogenic microorganisms that live in fresh water for over one hundred years. The organic matter found in surface waters containing humic substances that can react with chlorine, generating potentially carcinogenic halogenated organic compounds, especially trihalomethanes. The main trihalomethanes that are formed are chloroform, bromodichloromethane, bromoform and the dibromochloromethane, and the sum of the concentrations of these four products is called total trihalomethanes. In water treatment plants (WTP), the stage of pre-oxidation with chlorine significantly contributes to the formation of these compounds. This research aimed to evaluate the formation of trihalomethanes after conventional treatment of water from the simulation of four different routes in bench tests (Jar-test), and specimens removed from the water treatment plants in the study. The trihalomethanes were quantified by gas chromatography with electron capture detector. Samples were collected from raw water from two springs of the state of Espirito Santo (Jucu and Sahy River), with different color, absorbance at 254 nm and turbidity. Two Oxidants were tested in analyses: chlorine (as calcium hypochlorite) and potassium permanganate. The results showed that the formation of trihalomethanes was lower when the water samples were treated with potassium permanganate in the pre-oxidation, when compared with samples treated with chlorine. A similar result occurred in the potential for trihalomethane formation for 24 hours. In relation to the potencial formation of seven days, both springs were shown to be capable of forming compounds precursors of trihalomethanes. Concentrations of trihalomethanes above the limit allowed by the Ordinance of Ministry of Health number 518 were only detected in samples of treated water from the Sahy River

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