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Efficiency and Selectivity in the Chlorate ProcessLindberg, Aleksandra January 2021 (has links)
This licentiate thesis presents experimental studies concerning two parts of the electrochemical cell in the chlorate process: a cathode and an anode. Newly synthesized MnOx electrodes were investigated for the cathodic reaction, hydrogen evolution reaction (HER) in the chlorate process. In industry addition of toxic and carcinogenic chromium (VI) as sodium dichromate provides high efficiency. Here undesirable addition of sodium dichromate was avoided while high cathodic efficiency was achieved. Cathodic efficiency and selectivity towards HER, achieved by the MnOx electrodes annealed at different temperatures, were measured by means of mass spectrometry (MS). The second study investigated oxygen evolution in the chlorate process, which is an anodic side reaction. The evolution of oxygen decreases anodic efficiency and also presents a safety risk due to occurrence of HER in the undivided cell. We followed the amount of produced oxygen by two types of the electrode TiRu, similar to that industrially used, and synthesized TiRuSnSb, by means of MS. The produced oxygen amount was compared to the amount produced by Pt. To our best knowledge, this was the first study that successfully disentangles three different sources of oxygen with good time resolution. Oxygen is produced by homogenous hypochlorite decomposition, heterogeneously by different catalysts present in the electrolyte solution and anodically during the electrolysis i.e. electrochemically. Different electrode materials catalyzed hypochlorite decomposition differently and led to a different volume of oxygen produced. / Denna licentiatavhandling redogör för experimentella studier av tvådelar av den elektrokemiska cell som används i kloratprocessen:katoden och anoden. Syntetiserade MnOx elektroder utvärderades för katodreaktionen,vätgasutveckling, i kloratprocessen. Industriellt tillsätts giftigt ochcancerogent krom(IV) som natriumdikromat för hög verkningsgrad. Denna studie uteslöt oönskad tillsats av natriumdikromat samtidigt som hög katodisk effektivitet erhölls. Katodisk effektivitet och selektivitet för vätgasutveckling, med MnOx elektroder,värmebehandlade vid olika temperaturer, uppmättes med masspektrometer. I den andra studien undersöktes syrgasutveckling i kloratprocessen,vilket är en anodisk sidoreaktion. Syrgasutvecklingen minskar den anodiska effektiviteten och utgör en säkerhetsrisk med anledning avden pågående vätgasutvecklingen i den odelade cellen. Vi uppmättemängden producerad syrgas med två olika elektroder TiRu, liknandeden som industriellt används, och syntetiserad TiRuSnSb, med masspektrometer. Den producerade syrgasmängden jämfördes med mängden producerat på Pt. Såvitt vi vet var detta den första studiesom särskiljer på tre olika syrgaskällor med god tidsupplösning. Syrgas produceras homogent av hypokloritsönderfall, heterogent av olika katalysatorer närvarande i elektrolyten och anodiskt vid elektrolys dvs. elektrokemiskt. Olika elektrodmaterial katalyserade hypokloritsönderfall olika och producerade olika volym syrgas. / <p>QC 2021-04-28</p>
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Use of electromagnetic stimulation on an Enterococcus faecalis biofilm in root canal treated teeth in vitroKindler, Justin K. January 2019 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Nonsurgical root canal therapy procedures aim to reduce the total microbial load within an infected root canal system through chemomechanical debridement of the root canal system via instrumentation in conjunction with an antibacterial irrigating solution. The most commonly used irrigant is sodium hypochlorite, often at concentrations toxic to human cells. Electromagnetic wave irradiation is a novel method of disinfection that has been shown to be bactericidal against planktonic microorganisms in solution, but its efficacy against an established biofilm is unknown. Pilot studies have demonstrated a synergistic killing effect with sodium hypochlorite through a process termed electromagnetic stimulation (EMS). If confirmed, lower concentrations of the current gold standard of 6.0-percent sodium hypochlorite could be used to irrigate infected root canals during endodontic treatment, resulting in less toxicity to human cells. There are also regenerative implications as EMS could be used to disinfect the root canals of immature teeth using 1.5-percent sodium hypochlorite, as recommended by the American Association of Endodontists.
Objectives: The purpose of this in-vitro study was to evaluate the anti-biofilm effect of EMS against an established biofilm of Enterococcus faecalis.
Materials and Methods: Single rooted teeth were cut to a standardized length (12 mm) and instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with E. faecalis, which grew for two weeks to form an established biofilm. There were five treatment groups: 1) 6.0-percent sodium hypochlorite; 2) 1.5-percent sodium hypochlorite; 3) 1.5-percent sodium hypochlorite with EMS; 4) 0.9-percent saline with EMS and 5) 0.9-percent saline. Samples were collected, plated, and incubated for two days. The number of CFUs/mL was determined and converted to log10. The effect of treatment group on bacterial counts was made using Wilcoxon Rank Sums Test. One sample per group was scored and split for confocal imaging.
Null Hypothesis: Teeth treated with EMS in combination with 1.5-percent sodium hypochlorite or 0.9-percent saline will not demonstrate a significant anti-biofilm effect in comparison to those treated with 6.0-percent sodium hypochlorite alone.
Results: 0.9-percent saline and 0.9-percent saline with EMS were significantly higher than 6.0-percent NaOCl, 1.5-percent NaOCl, and 1.5-percent NaOCl with EMS. 0.9-percent saline was significantly higher than 0.9-percent saline with EMS. The three groups that included treatment with NaOCl were not significantly different from each other. Confocal imaging confirmed the CFU findings.
Conclusion: Because there was no growth in any of the NaOCl groups, the null hypothesis cannot be rejected. However, there was an antibiofilm effect when comparing the two saline groups, demonstrating that EMS has an antibiofilm effect. Future studies should focus on determining what concentration of NaOCl is most effective in combination with EMS.
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Effectiveness of ozonated water irrigation against an established Enterococcus faecalis biofilm in root canal treated teeth in vitroBroady, Adam B. January 2020 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: One of the main objectives of endodontic therapy is to reduce microbes and remove inflamed pulpal tissue within the root canal system (RCS). This is accomplished through chemomechanical debridement of the RCS using hand and rotary instrumentation along with an antimicrobial irrigant. Today, the most commonly used irrigant is sodium hypochlorite (NaOCl), often at concentrations toxic to human cells. The use of ozone as an endodontic irrigant is a novel technique that has been proven to be antimicrobial against several microorganisms. However, independent research is lacking on ozone’s efficacy against an established endodontic biofilm. If ozone’s efficacy against biofilms is confirmed, the use of toxic and potentially dangerous sodium hypochlorite could be replaced in some clinical situations (i.e., regeneration, immature teeth, resorption) with a safer and effective alternative.
Objective: The aim of the current study was to evaluate the anti-biofilm activity of different concentrations of ozonated water compared to various concentrations of NaOCl against an established endodontic biofilm of Enterococcus faecalis in root canal treated teeth in vitro.
Materials and Methods: The crowns of similarly sized, maxillary anterior teeth were removed, and the roots cut to a standard length (12 mm). All root canals were instrumented to a standard size. Specimens were sterilized and then inoculated with E. faecalis, which were allowed to grow for two weeks to form an established biofilm. There were six treatment groups: 1) 6% NaOCl; 2) 1.5% NaOCl; 3) 16µg/mL ozonated water; 4) 25µg/mL ozonated water; 5) 50µg/mL ozonated water, and 6) saline. Following treatment, samples were collected, plated, and incubated for two days. The number of CFU/mL were determined, and samples visualized using confocal imaging. The effect of treatment group on bacterial counts was made using one-way ANOVA followed by pair-wise comparisons.
Null Hypothesis: Endodontically treated teeth irrigated with ozonated water will not demonstrate a statistically significant decrease in the E. faecalis biofilm compared to those treated with sodium hypochlorite
Results: CFUs were converted to log10 and compared using Fisher’s Exact tests or one-way ANOVA followed by pair-wise tests. In all observations utilizing NaOCl irrigation, no colonies formed following treatment. The two NaOCl groups, with 0 CFU/mL, were significantly different than the other four groups (p=0.009). Saline showed a trend towards higher CFU/mL than 50 µg/ml O3 (p=0.068). None of the other comparisons approached statistical significance (p=0.453 25 µg/ml O3, p=0.606 16 µg/ml O3, p=0.999 25 µg/ml O3 vs 50 µg/ml O3, p=0.990 16 µg/ml O3 vs 50 µg/ml O3, p=1.000 16 µg/ml O3 vs 25 µg/ml O3). Confocal imaging helped illustrate effects of irrigation and confirm CFU findings.
Conclusion: The results of this study failed to reject the null hypothesis. There was a statistically significant difference in the E. faecalis biofilm remaining in the groups treated with ozonated water compared to those treated with NaOCl. However, there was a trend towards higher CFU/mL in the saline group compared to the 50µg/mL ozonated water group. According to this finding, future studies should evaluate the effects of higher concentrations of ozonated water against an established E. faecalis biofilm. In addition, other follow-up studies might include ozonated water’s effect on human cells, such as the stem cells of the apical papilla that are so critical to the success of regenerative endodontic procedures.
Due to university and laboratory closures caused by the COVID-19 pandemic, this project was stopped short and an insufficient sample size did not allow for proper statistical power. Additional occasions should be run upon the university’s re-opening to allow for proper statistical power.
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A Thermometric Titration Study of Acetaminophen and Sodium HypochloriteRelli-Dempsey, Vincent M.T., Relli-Dempsey 14 May 2018 (has links)
No description available.
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Nanopartikel und Ultraschall als Hilfsmittel zur Wurzelkanalreinigung / Nanoparticles and ultrasonic irrigation as adjuvants for root canal disinfectionBeckmann, Christoph 10 November 2016 (has links)
Ziel der Studie: Untersucht wurde die Entfernung von Debris aus präparierten Vertiefungen in der Wurzelkanalwand extrahierter Zähne mit ultraschall- und schallaktivierter Spülung. Als Spüllösungen wurden Natriumhypochlorit und Nanopartikel verwendet.
Material und Methode: Es wurden 74 extrahierte, einwurzelige Zähne in sechs Gruppen (4 Hauptgruppen mit je 15 Zähnen und 2 Kontrollgruppen mit je 7 Zähnen) aufgeteilt. Die Zähne gekürzt und mit Nickel-Titan-Instrumenten maschinell auf eine Größe von ISO 40/.04 präpariert und zwischen den Instrumenten wurde mit jeweils 2 ml 3%igem Natriumhypochlorit mit einer Handspritze gespült. Die Abschlussspülung erfolgte mit 5 ml EDTA (17%) und 5 ml NaOCl (3%). Mit einer Trennscheibe wurden die Zähne eingekerbt und longitudinal in zwei Zahnwurzelhälften gespalten. Anschließend wurde in jede Wurzelhälfte entweder eine Grube von 4 mm Länge oder 3 Löcher von 0,3 mm Durchmesser in die apikalen Anteile der Wurzelkanäle präpariert. Die Vertiefungen wurden mit Debris gefüllt und wieder zusammengesetzt. Die anschließende Spülung erfolgte mit der schallaktivierten Komet SF65-Spülfeile und der ultraschallaktivierten Acteon IrriSafe-Spülnadel der Größe ISO 20 jeweils mit Natriumhypochlorit und Nanopartikeln. Die Handspülung mit Spritze und Kanüle der Größe 30 diente als Spültechnik für die Kontrollgruppen. Die Zähne wurden anschließend wieder getrennt und anhand von Fotografien von zwei Untersuchern anhand eines vierstufigen Score-Systems bewertet. Die statistische Auswertung erfolgte mit einem nichtparametrischen Analyseverfahren.
Ergebnis: Sowohl die ultraschall- als auch die schallaktivierte Spülspitze war in der Lage, mit Natriumhypochlorit alle oder fast alle Vertiefungen sehr gut zu reinigen. Die Nanopartikel reinigten lediglich in der Gruppe der schallbasierten Spülung die Vertiefungen ausreichend gut. Die Handspülung lieferte keine zufriedenstellenden Ergebnisse.
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Análise química do precipitado formado na reação entre hipoclorito de sódio e digluconato de clorexidina / Chemical analysis of the precipitate formed by mixing sodium hypochlorite and chlorhexidine digluconateBrum, Thiago Cardoso Bulhões 14 August 2012 (has links)
O digluconato de clorexidina reage com o hipoclorito de sódio formando um precipitado, que segundo a literatura, é composto por para-cloroanilina (PCA), ou por para-clorofenil uréia (PCU) e para-clorofenilguanidil-1,6-diguanidil-hexano (PCGH). Este estudo visou analisar quimicamente os produtos formados e a presença de PCA no precipitado. Para isso, foi realizada a reação de 50 mL de solução de hipoclorito de sódio a 5% (NaOCl) e de 50 mL de solução de digluconato de clorexidina a 2% (CLX) em proporções iguais (1:1). O precipitado foi separado do sobrenadante e desidratado. A CLX pura, uma amostra do precipitado puro e outra amostra de precipitado com adição de PCA foram diluídas em dimetilsulfóxido deuterado e analisados em ressonância magnética nuclear 1D 1H (RMN) para verificar, por comparação, a presença da PCA no precipitado e para obtenção dos deslocamentos químicos dos produtos presentes no precipitado. Outra amostra do precipitado, de solução de CLX e de PCA foram separadas em cromatografia líquida de alta eficiência e analisadas em espectrômetro de massa (HPLC-ESI-MS) para identificação dos pesos moleculares dos compostos. A comparação do espectro do precipitado puro e do espectro do precipitado com adição de PCA permitiu analisar que o dubleto presente na região dos compostos aromáticos, referente à PCA, não está presente no espectro do precipitado puro demonstrando que não há PCA no precipitado. A análise do espectro de RMN do precipitado puro sugere que há formação de compostos com um e dois anéis aromáticos. Os espectros de massa permitem sugerir que há quebra da molécula de CLX, pelo hipoclorito de sódio, em sítios específicos (grupo biguanidil) que resultam na formação de fragmentos da molécula de clorexidina que se reorganizam formando oligômeros, ou seja, moléculas em que algumas unidades se repetem e, uma vez formadas, são estáveis e insolúveis em água. É possível concluir que no precipitado não há presença de PCA, sugerindo-se que haja PCGH e outros compostos com pesos moleculares maiores que o da clorexidina, denominados, neste estudo, C3, C4, C5, C6 e C7. / The reaction between chlorhexidine digluconate and sodium hypochlorite result in a precipitate, which according to the literature, is composed of para-chloroaniline (PCA), or para-chlorophenylurea (PCU) and para-chlorophenylguanidyl-1,6- diguanidyl-hexane (PCGH). The purpose of this study was to determine the chemical composition, the relative molecular weight of the compounds and whether PCA is formed in the precipitate. A 2% chlorhexidine digluconate solution was mixed in a 1:1 ratio with 5% NaOCl solution producing the precipitate. It was centrifuged, separed from the supernatant and dried. Pure CHX, the precipitate, as well as a mixture of precipitate and pure PCA were dissolved in deuterated dimetilsulfoxide and then analyzed using one-dimensional 1H nuclear magnetic resonance (MNR) to determine whether PCA was formed and to obtain precipitates chemical shifts. Other precipitate, CHX digluconate solution and PCA samples were analized using high performance liquid chromatography - electrospray ionization - mass spectrometry (HPLC-ESI-MS). Comparing the spectrum of the precipitate alone and precipitate with PCA allow to identify that PCA doublet peaks are not present in the spectrum of the precipitate alone, demonstrating that there are no PCA in the precipitate. NMR spectrum of the precipitate alone suggests that there is compounds with one and two aromatic rings. Mass spectra suggests that breaks in chlorhexidine molecule on specific sites (biguanidil groups), by sodium hypochlorite, results in fragments that forms oligomers molecules in wich some units are repeated and, once formed, are stable and insoluble in water. On the basis of this study, there is no PCA in the precipitate and suggesting that there may be other compounds like PCGH and others compounds, all of which are bigger in size than CHX, called, in this study, C3, C4, C5, C6 and C7.
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Eliminación del Biofouling en intercambiadores de calor-condensadores que minimicen el impacto ambiental en el medio marinoRío Calonge, Belén 28 September 1999 (has links)
La presente tesis doctoral tiene por objeto tratar de eliminar el fenómeno no deseable de formación de biofouling en diferentes superficies tubulares de intercambiadores de calor, mediante tratamientos físicos y químicos, intentando minimizar el impacto ambiental creado en los efluentes de las instalaciones industriales.El equipo experimental está compuesto por una planta piloto de intercambiadores de calor condensadores dotada de ocho tubos que funcionan como sistemas independientes, donde se controlan los parámetros de presión, temperatura y caudal, que define indirectamente el biofouling depositado en el interior de dichos tubos a través de los valores de resistencia friccional al flujo y resistencia a la transferencia de calor.También ha sido diseñado y construido otra planta piloto o monitor "MCMDID" (monitor combinado de medición directa e indirecta del biofouling) donde se mide en continuo el espesor del biofouling adherido a la superficie de un tubo del mismo material que los ensayados en la planta descrita anteriormente.
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EFEITO DA IMERSÃO PERIÓDICA EM SOLUÇÕES LIMPADORAS NA RUGOSIDADE SUPERFICIAL, PORCENTAGEM DE VARIAÇÃO DE MASSA E RESISTÊNCIA FLEXURAL DE LIGAS DE COBALTO-CROMO / Co-Cr ALLOY IMMERSION IN CLEANING SOLUTIONS: EFFECTS ON FLEXURAL STRENGTH, SURFACE ROUGHNESS AND PERCENTUAL OF VARIATION OF MASSBorsa, Pedro Carlos Cortiana 22 August 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to evaluate the flexural strength, elastic modulus,
mass changes and surface roughness of two cobalt-chromium alloys, before and
after immersions in four cleaning solutions and distilled water (as control). Co-Cr
alloys (Co-Cr®, Dentsply-DeguDent Industria e Comércio, São Paulo, Brasil; and GM
800+®, Dentaurum GmbH & Co KG, Ispringen, Alemanha) were investigated. Fifty
bar specimens (25 x 3 x 0,5 mm) for the flexural test, 50 quadrangular specimens
(10 x 10 x 1 mm) for mass changes evaluation and 35 cylindrical specimens (10 x 1
mm) for surface roughness measurements were obtained by casting. They were
polished by abrasive paper (#240 to #2500) and diamond polishing paste (3μm).
Specimens were randomly divided into 5 groups according the following cleaning,
solutions: pure white vinegar, 0.2% peracetic acid, sodium perborate - Corega
Tabs®, 0.37% sodium hypochlorite and the control, distilled water. Surface
roughness (Ra parameter) was analyzed using a profilometer (Mitutoyo SJ 410,
Mitutoyo Corp, Kanagawa, Japan) before and after 5, 20 e 90 immersions (10 min
each). Ra changes (ΔRa5, ΔRa20 e ΔRa90) were calculated for the different
intervals. Qualitative surface analyses were performed by Scanning Electron
Microscope (JSM 6360 SEM, JEOL). Both alloys, immersed in pure white vinegar,
0.2% peracetic acid, sodium perborate - Corega Tabs®, 0.37% sodium hypochlorite
had similar roughness changes after 90 immersions (ΔRa from -0,012 to 0,022 μm).
There was a significant surface roughening in hypochlorite (ΔRa90= 0,064 μm for
CoCr®; and ΔRa90 = 0,592 μm for GM 800+). The number of immersions influenced
on the roughness changes only in hypochlorite and there were greater changes in
the GM 800+ alloy. After 90 immersions, GM 800+ alloy showed mass lost in the
hypochlorite solution (-0,3%). This alloy presented higher flexural strength after 90
immersions in SH (σF= 1516 MPa in hypochlorite; 1366 MPa in control). However,
there were no elastic modulus changes. CoCr® alloy did not present differences in
the σF or in elastic modulus in any solution. The only solution that damaged the alloy
surface was 0.37% sodium hypochlorite. / O objetivo deste trabalho foi avaliar a rugosidade superficial,o percentual de variação
de massa, a resistência flexural e o módulo de elasticidade de duas ligas de Cobalto-Cromo
após submetidas à imersões em quatro soluções limpadoras e água (controle). Foram
utilizadas as ligas Co-Cr® DeguDent (Dentsply-DeguDent Industria e Comércio, São
Paulo, Brasil) e Remanium® GM 800+ (Dentaurum GmbH & Co KG, Ispringen, Alemanha).
De cada liga fundiu-se cinquenta corpos de prova, 50 cilíndricos (10 x 1 mm) para a análise
da rugosidade, 50 quadrangulares (10 x 10 x 1 mm) para avaliação da variação de massa e
em formato retangular (25 x 2,5 x 0,75 mm) para o teste flexão 3 pontos. O polimento se deu
por seqüencia de lixas (#400 a 2500) e pasta diamantada (3μm). A distribuição aleatória foi
em 5 grupos, conforme os agentes de limpeza: vinagre branco puro, ácido peracético 0,2% ,
perborato de sódio (Corega Tabs®), hipoclorito de sódio 0,37% e o controle: água destilada.
Foram realizadas avaliações da rugosidade superficial (Parâmetro Ra) através de
rugosímetro (Mitutoyo SJ 410, Mitutoyo Corp, Kanagawa, Japan) antes e após 5, 20 e 90
ciclos de imersão de 10 minutos. As alterações de Ra (ΔRa5, ΔRa20 e ΔRa90) foram
calculadas entre os diferentes interrupções. Análise complementar da superfície foi realizada
em imagens obtidas por microscopia eletrônica de varredura (JSM 6360 SEM, JEOL Ltd.,
Tokyo, Japan). A pesagens dos corpos de prova para cálculo da variação de massa se deu
após 5 e 90 imersões, utilizando-se de balança eletrônica analítica com sensibilidade de
0,0001 g (FA 2004, Coleman E. P. L. Com. e Imp. Ltda. Santo André, São Paulo). Os
ensaios de flexão a 3 pontos para determinação da resistência flexural (σF) e do módulo de
elasticidade foram realizados após 90 imersões. Os dados obtitos foram analisados quanto
a normalidade e testes de comparação entre médias foram aplicados conforme o tipo de
distribuição. As duas ligas, imersas nas soluções vinagre puro, ácido peracético, corega
tabs® apresentaram comportamento semelhante em relação as alterações de rugosidade
superficial (Ra), quando comparadas ao controle, após 90 imersões (ΔRa entre -0,012 e
0,022 μm). Aumento da rugosidade significativo ocorreu na solução de hipoclorito (ΔRa90=
0,064 μm (CoCr®) e 0,592 μm (GM 800+). O número de imersões influenciou na variação de
rugosidade, apenas para a solução de hipoclorito, sendo que as maiores variações
ocorreram na liga GM 800+. Após 90 imersões a liga GM 800+ demonstrou perda de massa
na solução de hipoclorito (-0,3%). Ocorrendo para essa liga aumento da resistência flexural
(σF= 1516 MPa em hipoclorito; 1366 MPa no controle) após 90 imersões, sem modificação
de seu módulo de elasticidade. A liga CoCr® não apresentou diferenças na σF ou no
módulo de elasticidade nas diferentes soluções. A única solução que causou dano à
superfície das ligas foi o hipoclorito de sódio 0,37%.
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Análise química do precipitado formado na reação entre hipoclorito de sódio e digluconato de clorexidina / Chemical analysis of the precipitate formed by mixing sodium hypochlorite and chlorhexidine digluconateThiago Cardoso Bulhões Brum 14 August 2012 (has links)
O digluconato de clorexidina reage com o hipoclorito de sódio formando um precipitado, que segundo a literatura, é composto por para-cloroanilina (PCA), ou por para-clorofenil uréia (PCU) e para-clorofenilguanidil-1,6-diguanidil-hexano (PCGH). Este estudo visou analisar quimicamente os produtos formados e a presença de PCA no precipitado. Para isso, foi realizada a reação de 50 mL de solução de hipoclorito de sódio a 5% (NaOCl) e de 50 mL de solução de digluconato de clorexidina a 2% (CLX) em proporções iguais (1:1). O precipitado foi separado do sobrenadante e desidratado. A CLX pura, uma amostra do precipitado puro e outra amostra de precipitado com adição de PCA foram diluídas em dimetilsulfóxido deuterado e analisados em ressonância magnética nuclear 1D 1H (RMN) para verificar, por comparação, a presença da PCA no precipitado e para obtenção dos deslocamentos químicos dos produtos presentes no precipitado. Outra amostra do precipitado, de solução de CLX e de PCA foram separadas em cromatografia líquida de alta eficiência e analisadas em espectrômetro de massa (HPLC-ESI-MS) para identificação dos pesos moleculares dos compostos. A comparação do espectro do precipitado puro e do espectro do precipitado com adição de PCA permitiu analisar que o dubleto presente na região dos compostos aromáticos, referente à PCA, não está presente no espectro do precipitado puro demonstrando que não há PCA no precipitado. A análise do espectro de RMN do precipitado puro sugere que há formação de compostos com um e dois anéis aromáticos. Os espectros de massa permitem sugerir que há quebra da molécula de CLX, pelo hipoclorito de sódio, em sítios específicos (grupo biguanidil) que resultam na formação de fragmentos da molécula de clorexidina que se reorganizam formando oligômeros, ou seja, moléculas em que algumas unidades se repetem e, uma vez formadas, são estáveis e insolúveis em água. É possível concluir que no precipitado não há presença de PCA, sugerindo-se que haja PCGH e outros compostos com pesos moleculares maiores que o da clorexidina, denominados, neste estudo, C3, C4, C5, C6 e C7. / The reaction between chlorhexidine digluconate and sodium hypochlorite result in a precipitate, which according to the literature, is composed of para-chloroaniline (PCA), or para-chlorophenylurea (PCU) and para-chlorophenylguanidyl-1,6- diguanidyl-hexane (PCGH). The purpose of this study was to determine the chemical composition, the relative molecular weight of the compounds and whether PCA is formed in the precipitate. A 2% chlorhexidine digluconate solution was mixed in a 1:1 ratio with 5% NaOCl solution producing the precipitate. It was centrifuged, separed from the supernatant and dried. Pure CHX, the precipitate, as well as a mixture of precipitate and pure PCA were dissolved in deuterated dimetilsulfoxide and then analyzed using one-dimensional 1H nuclear magnetic resonance (MNR) to determine whether PCA was formed and to obtain precipitates chemical shifts. Other precipitate, CHX digluconate solution and PCA samples were analized using high performance liquid chromatography - electrospray ionization - mass spectrometry (HPLC-ESI-MS). Comparing the spectrum of the precipitate alone and precipitate with PCA allow to identify that PCA doublet peaks are not present in the spectrum of the precipitate alone, demonstrating that there are no PCA in the precipitate. NMR spectrum of the precipitate alone suggests that there is compounds with one and two aromatic rings. Mass spectra suggests that breaks in chlorhexidine molecule on specific sites (biguanidil groups), by sodium hypochlorite, results in fragments that forms oligomers molecules in wich some units are repeated and, once formed, are stable and insoluble in water. On the basis of this study, there is no PCA in the precipitate and suggesting that there may be other compounds like PCGH and others compounds, all of which are bigger in size than CHX, called, in this study, C3, C4, C5, C6 and C7.
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Estudos de remoção de 17 'alfa'-etinilestradiol de aguas para abastecimento, utilizando dioxido de cloro, hipoclorito de sodio, carvão ativado em po (cap) e tratamento fisico-quimico / Studies of 17 'alfa'-etinilestradiol removal from supplying water, using chorine dioxide, sodium hipoclorite, powder activated carbon (cap) and physicist-chemistry treatmentFernandes, Roberto, 1972- 30 August 2007 (has links)
Orientador: Ruben Bresaola Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T06:31:37Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo: O 17'alfa'-Etinilestradiol é um princípio-ativo sintético presente na formulação dos contraceptivos utilizados por parcela expressiva da população feminina. Por ser um composto persistente, o 17'alfa'-Etinilestradiol não absorvido pelo organismo da mulher, fração que pode chegar a 80%, é eliminado pela usuária, principalmente pela urina. Na rede de esgotos, mesmo sobre a existência de tratamento, este não é removido completamente, alcançando, posteriormente, mananciais que podem ser utilizados para abastecimento público. Nesse sentido, o presente trabalho teve por objetivo estudar as eficiências de remoção do 17'alfa'-Etinilestradiol de águas para abastecimento, quando empregadas as tecnologias: pré-oxidação com Hipoclorito de Sódio ou Dióxido de Cloro, adsorção em carvão ativado em pó (CAP) e tratamento físico-químico composto de coagulação, floculação, sedimentação e filtração rápida. A metodologia empregada para as determinações do estrogênio foi a cromatografia líquida de alta eficiência (CLAE), aplicada após processo de extração em fase sólida (EFS) do analito presente na água. O cromatógrafo HPLC utilizado, possuía coluna cromatográfica modelo C18, de fase reversa e detector de arranjo de diodos com UV. O trabalho mostrou que o Hipoclorito de Sódio foi mais efetivo que o Dióxido de Cloro, na oxidação do 17'alfa'- Etinilestradiol. Sua maior ação foi observada sob dosagens de 5 e 10 mg/L e tempos de oxidação entre 3 e 5 horas. Esta combinação de parâmetros experimentais impactou na redução da concentração do estrogênio na água, em níveis superiores a 97,5%. Este nível de remoção também foi observado, quando aplicado carvão ativado em pó, sob dosagens a partir de 50 mg/L e tempo de contato de 60 minutos. O tratamento físico-químico apresentou melhores resultados quando aumentada a dosagem de carvão para 5 mg/L. Os resultados alcançados constituem-se de fundamental importância na formação de base para futuras soluções dedicadas ao problema, dada a escassez de estudos de remoção de fármacos contaminantes da água / Abstract: The 17'alfa'-Etinilestradiol is a synthetic active pharmaceutical ingredient presents in the formulation of contraceptives used by a large amount of the female population. As a bioaccumulative molecule, the 17'alfa'-Etinilestradiol is not completely absorbed by woman organism; up to 80% can be eliminated by user, mainly by urine. Even after sewage treatment, the residual of 17'alfa'-Etinilestradiol it is not totally removed reaching, later, water sources that can be used for public supplying. In this direction, the present work has for objective the study of 17'alfa'-Etinilestradiol removal efficiency in waters supplies, using different technologies such as: pre-oxidizing with Sodium Hypochlorite or Chlorine Dioxide, adsorption in powder activated carbon (CAP) and physic-chemical treatment composed by coagulation, flocculation, sedimentation and fast filtration. The methodology used for the estrogen determination was the High Performance Liquid Chromatography (HPLC), applied after solid phase extraction process (SFE) of the hormone present in water. The HPLC equipment used was composed by a model C18 chromatographic column with reverse phase, and diodes arrangement detector, with UV. The work showed that the Sodium Hypochlorite was more effective than the Chlorine Dioxide, to the 17'alfa'-Etinilestradiol oxidizing. Its higher action was observed when applying 5 and 10 mg/L of oxidants in a time of reaction between 3 and 5 hours. This interaction between concentration of oxidant and time of reaction provided estrogen concentration reduction in water, in levels upper to 97.5%. This same removal level also was observed when applied powder activated carbon, mainly when 50 mg/L in a contact time of 60 minutes was performed. The physic-chemical treatment presented better results when 5 mg/L of activated carbon was applied. The present results consist of fundamental importance in the base formation for future solutions dedicated to the problem, due to lack of studies present now a days in pharmaceutical products removal from water / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil
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