Dissertations / Theses on the topic 'Advanced oxidation processes (AOP)'
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RAMAKRISHNAN, BALAJI. "TREATMENT OF MTBE CONTAMINATED WATERS USING AIR STRIPPING AND ADVANCED OXIDATION PROCESSES." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131024170.
Full textStříteský, Luboš. "Využití oxidačních procesů (AOP) pro odstraňování mikropolutantů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226161.
Full textGraça, Cátia Alexandra Leça. "DEGRADATION OF PERSISTENT PESTICIDES VIA ADVANCED OXIDATION AND REDUCTIVE PROCESSES." Doctoral thesis, Universidade de São Paulo, 2017. http://hdl.handle.net/10362/48570.
Full textNa presente Tese de Doutorado foram abordados tanto processos oxidativos avançados (POA), como processos redutivos por metais de valência zero, na degradação de dois pesticidas considerados persistentes no meio ambiente: amicarbazona (AMZ) e clorpirifós (CP). No capítulo I são apresentados os estudos realizados com diversos POA, mediados por radicais sulfato (SO4o-) e hidroxila (oOH), aplicados da AMZ. Num primeiro estudo foi explorada a ativação do oxidante persulfato (PS), de diferentes formas, tais como radiação UVA, H2O2 e Fe(II), assim como a combinação de radiação UVA com Fe(II), Fe(III) e complexos de Fe(III). Aqui também foram investigados os efeitos de diversas variáveis reacionais, tais como pH, concentração inicial de reagentes e de pesticida, adição de um segundo oxidante (H2O2) e adição de diferentes espécies de ferro. Os testes realizados, para efeito de controle, referentes à irradiação das espécies de Fe(III) na ausência de PS, despertaram o interesse para um estudo mais aprofundado sobre o efeito da fotólise destas espécies na degradação da AMZ, surgindo assim o segundo trabalho. Neste utilizou-se um projeto experimental de Doehlert, para avaliar o efeito de duas variáveis em simultâneo quanto à degradação da AMZ: pH e proporção Fe(III): ligante, sendo o ligante um dos seguintes carboxilatos: oxalato, citrato ou tartarato. Um modelo de superfície de resposta, que correlaciona a taxa de degradação observada (kobs) em função do pH e proporção Fe(III):ligante foi obtido para cada um dos complexos de Fe(III) estudados. Os processos explorados, tanto no primeiro como no segundo estudo, se mostraram eficazes na remoção da AMZ, porém nada se sabe acerca da remoção da toxicidade. Para tal, foi desenvolvido um terceiro estudo dedicado à avaliação da toxicidade da solução de AMZ, antes e após a aplicação de cada um dos processos anteriormente abordados, contra cinco micro-organismos: Vibrio fischeri (toxicidade aguda); Tetrahymena thermophila, Chlorella vulgaris (toxicidade crônica); Escherichia coli e Bacilus subtilis (atividade antimicrobiana). O último estudo abordado no capitulo I é referente à aplicação de metais de valência zero também nos POA, correlacionado assim o capítulo I e o capítulo II. Como tal, foi feito um estudo de ativação de PS por meio de ferro de valência zero (Fe0), em que se investigou a influência de diversas variáveis por forma a inferir sobre a aplicabilidade prática deste processo. Pesticidas organoclorados apresentam maior resistência à degradação por processos oxidativos do que redutivos, sendo preferível o último na degradação desta importante classe de contaminantes. Como tal, o capítulo II se refere à degradação redutiva, por meio de diferentes metais de valência zero e partículas bimetálicas, do pesticida organoclorado CP. Além do amplamente explorado Fe0, outros metais podem ser aplicados neste processo, pelo que, neste estudo, explorou-se a potencialidade de Zn0 e Cu0 comparativamente ao primeiro. Ainda neste estudo foram investigadas duas formas de aumentar a reatividade dos metais: i) no caso do Fe0 e Zn0, revestindo com um metal mais nobre (Cu), por forma a observar o efeito catalisador do último no sistema bimetálico; ii) realizando um pré-tratamento à superfície dos metais.
ROCHA, MANOELA DEMORI LACOMBE PENNA DA. "USE OF ADVANCED OXIDATION PROCESSES FOR PULP MILL WASTEWATER TREATMENT." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=32797@1.
Full textCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
O presente trabalho avalia a utilização de dois diferentes tipos de POA, Fenton-Zero - processo Fenton utilizando ferro zero valente: Fe0/H2O2 - e UV/H2O2 para o tratamento de efluente de indústria de celulose tratado biologicamente. Os parâmetros observados foram DBO, DQO, COT, cor e ABS280nm (medida de compostos ligninícos). Os experimentos foram conduzidos em batelada, em escala de laboratório e utilizando efluente real de indústria de celulose tratado biologicamente. Para os testes com o processo Fenton Zero foram realizados experimentos de acordo com um planejamento fatorial 2 elevado a 3, investigando a influência das variáveis pH, dosagem de peróxido de hidrogênio e massa de ferro zero valente fornecida por volume de solução. Como fonte de ferro foi utilizada lã de aço comercial nas concentrações de 5,5 g/L, 6,5 g/L e 7,5 g/L. As concentrações iniciais de peróxido de hidrogênio estudadas foram de 456,9 mg/L, 913,7 mg/L e 1370,6 mg/L e os valores de pH variaram entre 5.5, 6.5 e 7.5. Foram obtidas médias de remoção de 57,1 por cento de DQO, 67,2 por cento de DBO, 90,5 por cento de Cor, 83,4 por cento de compostos lignínicos e 54 por cento de COT, além de 9,52 mg/L de DBO final e 60,1 mg/L de DQO final. Já os testes com o sistema UV/H2O2 foram conduzidos com o único objetivo de polimento do efluente para reuso pelo processo. Desta maneira, o pH utilizado foi o natural do efluente (7,5) e três doses de H2O2 foram aplicadas, 4,0 g/L, 5,0 g/L e 6,0 g/L estando estas em excesso.
The present work evaluates the use of two different types of AOP: the Zero-Fenton - process using zero valent iron - and UV/H2O2 for the treatment of pulp mill wastewater biologically treated. The observed parameters were BOD, COD, TOC, color and ABS280nm (measure of lignin compounds). The experiments were conducted in batch, lab scale and with real wastewater from biological treatment of a cellulose plant in Brazil. For the Fenton process, experiments were carried out according to a factorial design 23 investigating the influence of the variables pH, hydrogen peroxide dosage and zero-valent iron mass supplied by solution volume. As iron source, commercial steel wool was used in the concentrations of 5.5 g / L, 6.5 g / L and 7.5 g / L. The concentrations of hydrogen peroxide studied were 456.9 mg / L, 913.7 mg / L and 1370.6 mg / L and pH values ranged from 5.5, 6.5 and 7.5. The average removal rate was 57.1 per cent COD, 67.2 per cent COD, 90.5 per cent Color, 83.4 per cent lignin compounds and 54 per cent TOC. Also 9,52 mg/L of final BOD and 60,1 mg/L of final COD. The trials with the UV/H2O2 system, on the other hand, were conducted with the sole objective of polishing the effluent for reuse in the process. The pH used was the effluent s natural (7.5) and three excess doses of H2O2 were applied.
Graça, Cátia Alexandra Leça. "Degradation of persistent pesticides via advanced oxidation and reductive processes." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-03082017-091224/.
Full textNa presente Tese de Doutorado foram abordados tanto processos oxidativos avançados (POA), como processos redutivos por metais de valência zero, na degradação de dois pesticidas considerados persistentes no meio ambiente: amicarbazona (AMZ) e clorpirifós (CP). No capítulo I são apresentados os estudos realizados com diversos POA, mediados por radicais sulfato (SO4o-) e hidroxila (oOH), aplicados da AMZ. Num primeiro estudo foi explorada a ativação do oxidante persulfato (PS), de diferentes formas, tais como radiação UVA, H2O2 e Fe(II), assim como a combinação de radiação UVA com Fe(II), Fe(III) e complexos de Fe(III). Aqui também foram investigados os efeitos de diversas variáveis reacionais, tais como pH, concentração inicial de reagentes e de pesticida, adição de um segundo oxidante (H2O2) e adição de diferentes espécies de ferro. Os testes realizados, para efeito de controle, referentes à irradiação das espécies de Fe(III) na ausência de PS, despertaram o interesse para um estudo mais aprofundado sobre o efeito da fotólise destas espécies na degradação da AMZ, surgindo assim o segundo trabalho. Neste utilizou-se um projeto experimental de Doehlert, para avaliar o efeito de duas variáveis em simultâneo quanto à degradação da AMZ: pH e proporção Fe(III): ligante, sendo o ligante um dos seguintes carboxilatos: oxalato, citrato ou tartarato. Um modelo de superfície de resposta, que correlaciona a taxa de degradação observada (kobs) em função do pH e proporção Fe(III):ligante foi obtido para cada um dos complexos de Fe(III) estudados. Os processos explorados, tanto no primeiro como no segundo estudo, se mostraram eficazes na remoção da AMZ, porém nada se sabe acerca da remoção da toxicidade. Para tal, foi desenvolvido um terceiro estudo dedicado à avaliação da toxicidade da solução de AMZ, antes e após a aplicação de cada um dos processos anteriormente abordados, contra cinco micro-organismos: Vibrio fischeri (toxicidade aguda); Tetrahymena thermophila, Chlorella vulgaris (toxicidade crônica); Escherichia coli e Bacilus subtilis (atividade antimicrobiana). O último estudo abordado no capitulo I é referente à aplicação de metais de valência zero também nos POA, correlacionado assim o capítulo I e o capítulo II. Como tal, foi feito um estudo de ativação de PS por meio de ferro de valência zero (Fe0), em que se investigou a influência de diversas variáveis por forma a inferir sobre a aplicabilidade prática deste processo. Pesticidas organoclorados apresentam maior resistência à degradação por processos oxidativos do que redutivos, sendo preferível o último na degradação desta importante classe de contaminantes. Como tal, o capítulo II se refere à degradação redutiva, por meio de diferentes metais de valência zero e partículas bimetálicas, do pesticida organoclorado CP. Além do amplamente explorado Fe0, outros metais podem ser aplicados neste processo, pelo que, neste estudo, explorou-se a potencialidade de Zn0 e Cu0 comparativamente ao primeiro. Ainda neste estudo foram investigadas duas formas de aumentar a reatividade dos metais: i) no caso do Fe0 e Zn0, revestindo com um metal mais nobre (Cu), por forma a observar o efeito catalisador do último no sistema bimetálico; ii) realizando um pré-tratamento à superfície dos metais.
Cabrera-Codony, Alba. "Siloxane removal in the energy recovery of biogas: sequential adsorption/oxidation processes." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/399731.
Full textAquesta tesi estudia l'eliminació de compostos volàtis de silici (siloxans) per la recuperació energètica del biogàs. Es van estudiar diferents adsorbents per l'adsorció de siloxans, determinants les propietats físico-químiques superficials que en condicionen l'eficiència, permetent millorar el rendiment de l'adsorció i permetent la regeneració en carbons actius i zeolites esgotats. La tesi estudia l'eliminació de siloxans a escala de laboratori en condicions properes a les reals del biogàs, incloent l'adosrció competitiva amb altres compostos orgànics volàtics, en presència d'humitat i amb diferents matrius gasoses, la qual cosa va permetre seleccionar els materials òptims per aquest propòsit.Per tant el coneixement derivat d'aquesta tesi és directament transferible per tal de millorar els sistemes d'eliminació siloxanes
Rani, Rupam. "REMOVAL OF EMERGING CONTAMINANTS FROM AQUEOUS SOLUTION BY OZONE -BASED PROCESSES." Master's thesis, Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/214782.
Full textM.S.Env.E.
The presence of emerging contaminants (ECs) in water and wastewater systems has become a subject of significant concern worldwide. These emerging contaminants are complex organic molecules which potentially affect human health and environment. Conventional wastewater treatment plants are unable to completely remove these contaminants from water and therefore can discharge them into environment. The need to develop effective methods for ECs removal is essential. This study assess the potential of ozone based advanced oxidation processes (AOP) to oxidize number of emerging contaminants. Different combinations of ozone with hydrogen peroxide and sodium persulfate were tested. For this study 1-4, dioxane, perfluorinated compounds (PFCs), N,N-Diethyl-metatoluamide, and three pharmaceuticals sulfamethoxazole, trimethoprim and carbamazepine have been selected. The effect of different process parameters such as chemical dosages, ozone weight percent, ozone flow rates, etc. on destruction of ECs were examined. It was observed that 1, 4-dioxane were persistent to direct ozone reaction, however were easily oxidized by hydroxyl radical. However, ozonation was solely very effective (> 99 %) in removing pharmaceuticals such as sulfamethoxaole, trimethoprim and carbamazepine. It was not very efficient for the removal of perfluorinated compound and N,N-Diethylmeta-toluamide. The operational conditions were optimized for maximum removal of every compound and their influence on the degradation process is discussed.
Temple University--Theses
Hansson, Henrik. "TREATMENT OF WASTEWATER GENERATED BY WOOD-BASED DRY INDUSTRIES: ADVANCED OXIDATION PROCESSES & ELECTROCOAGULATION." Doctoral thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-36437.
Full textTrä är ett material med ett stort antal möjliga användningsområden. Inom träindustrin har utvecklingen av vattenbehandlingsmetoder varit inriktat på de branscher som har vatten som en del av produktionen, såsom papper- och massaindustrin. Men det finns en stor och potentiellt växande sektor inom träindustrin som har försummats, den utgörs av industrier som inte har vatten som en del av produktionen, t.ex. trägolv och trämöbel industrier. Trots detta så producerar dessa industrier fortfarande relativt kraftigt förorenade avloppsvatten med t.ex. COD-värden upp till 30000 mg/l men i relativt låga volymer. Dessa avloppsvatten uppkommer vid rengöring av maskiner och städning av lokaler, varefter de oftast efter utspädning med dricksvatten skickas till det kommunala reningsverket. Väl där späds det förorenade vattnet vidare ut med annat inkommande vatten men passerar dock till stor del obehandlat och släpps ut i mottagande vattendrag eller så fastnar föroreningarna i avloppsslamet. Dagvatten är en annan typ av förorenat vatten från dessa "torra industrier" som ofta genereras i stora volymer och innehåller föroreningar som lakats från de trämaterial som förvaras i de stora upplag som ofta förekommer vid denna typ av industrier. Det övergripande syftet med avhandlingen var att öka kunskapen och kompetensen för att kunna miljömässigt riktigt och ekonomiskt billigt behandla industriavloppsvatten lokalt på plats inom trävaruindustrin, genom att använda en trä-golvsindustri som fallstudie. Fokus lades på kombinerade behandlingsmetoder och lösningar som skulle kunna vara lämpliga både för industriavloppsvatten och dagvatten. Ett antal behandlingstekniker har undersökts; elektrokoagulering studerades både som en fristående behandling och i kombination med aktivt kol. Den kombinerade behandlingen gav en COD-reduktion på ungefär 70 %. Flera avancerade oxidationsprocesser (AOP) studerades också, och en COD-reduktion på cirka 70% uppnåddes med en kombination av UV-ljus och Fenton behandling. Den mest framgångsrika behandlingen var ozon i kombination med UV-ljus där en COD-reduktion runt 90 % uppnåddes varvid en avsevärd förbättring av den biologisk nedbrytbarhet på det behandlade avloppsvattenet erhölls. Ozon visade sig också vara effektivt för nedbrytning av organiska föreningar (ca 70% COD reduktion) och förbättrade den biologiska nedbrytbarheten av föroreningarna i dagvattnet från den studerade industrin. Resultaten har visat att ozon kan anses vara ett lämpligt alternativ för att behandla industriavloppsvatten inom trävarusektorn och möjligen för att öka den biologiska nedbrytbarheten av dagvattnet från dessa industrier
Integrated Approach for Handling of Industrial Wastewater and Stormwater
Triple Helix Collaboration on Industrial Water Conservation in Småland and the Islands
Han, Hyungjin Civil & Environmental Engineering Faculty of Engineering UNSW. "Mechanisms and modelling of sonochemically-mediated free radical degradation of contaminants." Awarded by:University of New South Wales. Civil & Environmental Engineering, 2009. http://handle.unsw.edu.au/1959.4/43485.
Full textDemir, Duz Hande. "Application of Advanced Oxidation Processes in the Reclamation of Wastewaters from the Oil & Gas Sector." Doctoral thesis, Universitat Rovira i Virgili, 2020. http://hdl.handle.net/10803/670759.
Full textEsta tesis se enmarca dentro de dos proyectos relacionados con la recuperación (tratamiento + reutilización) de aguas residuales generadas por la industria del petróleo y gas. El objetivo del primer proyecto fue la reutilización de agua residual generada por la industria del petróleo y gas mediante el tratamiento de los denominados efluentes "downstream" con procesos de oxidación avanzados (AOPs). Para ello, se estudiaron varios procesos AOPs fotocatalíticos y basados en ozono, los cuales se aplicaron, en primer lugar, para el tratamiento de un agua sintética con una composición compleja representativa de agua residual de refinería (SRW). Tras los resultados obtenidos con SRW, se investigó el rendimiento del tratamiento en tres aguas residuales reales diferentes con el objetivo de alcanzar los requisitos para la reutilización del agua en la planta. El segundo proyecto se enfocó en el tratamiento de agua residual procedente del proceso de arenas petrolíferas (OSPW), que actualmente se encuentra almacenada en estanques debido a la política de descarga cero en la región de Alberta, en Canadá. En primer lugar, se compararon los tratamientos de ozonización y UV con diferentes oxidantes y pH. El tratamiento con UV/Fenton resultó ser un método eficaz para eliminar los componentes orgánicos presentes en el efluente que causan toxicidad aguda. También se investigaron las actividades catalíticas de catalizadores de carbón activado granulado previamente dopados con N o N/S y Fe (III). Se realizó una selección de los catalizadores más prometedores mediante diseño factorial fraccional en la ozonización catalítica de un agua sintética. Posteriormente, los materiales seleccionados se investigaron más a fondo para el tratamiento de OSPW real. Se estudiaron, además, procesos AOP basados en ozono en combinación con H2O2 y UVC con el objetivo de alcanzar la mineralización de los contaminantes orgánicos, incluidos los ácidos nafténicos presentes en el efluente. Un aumento en la mineralización repercute positivamente en la reducción de la toxicidad. Por primera vez se presenta el estudio de la combinación de UVC con tratamientos basados en O3 para tratar la OSPW.
This thesis has been developed within two projects dealing with the reclamation of wastewater generated by the oil & gas industry. The first project aimed at water reuse in the oil & gas sector treating the downstream effluents by advanced oxidation processes (AOPs). For this, several photo-based and ozone-based AOPs were assessed in detail starting from a synthetic refinery wastewater (SRW) with a complex composition. After the initial screening on SRW, the treatment performance of the different AOPs was investigated with three different real wastewaters, aiming at reaching the requirements for water reuse in the plant. The second project considered the treatment of oil sands process water (OSPW) currently stored in tailing ponds because of the zero-discharge policy in Alberta region, in Canada. Firstly, catalytic ozone-based and UV-based treatments with different oxidants and operating pH were compared. UV/Fenton treatment was considered as an effective method for removing the organic components present in the effluent that cause acute toxicity. The catalytic activities of granular activated carbon-based materials previously doped with heteroatom (N or N/S) and Fe (III) were also investigated. For catalytic ozonation of a synthetic water, a catalyst selection was performed based on the fractional factorial design. Afterwards, the selected materials were investigated further for the treatment of real OSPW. The use of ozone-based AOPs including H2O2 and UVC to achieve mineralization was examined in detail, while also aiming at reduction in toxicity arising from the organic components including naphthenic acids present in the effluent. UVC combination to O3-based treatments was studied for the first time to treat OSPW.
Badmus, Kassim Olasunkanmi. "Treatment of persistent organic pollutants in wastewater with combined advanced oxidation." University of the Western Cape, 2019. http://hdl.handle.net/11394/6785.
Full textPersistent organic pollutants (POPs) are very tenacious wastewater contaminants with negative impact on the ecosystem. The two major sources of POPs are wastewater from textile industries and pharmaceutical industries. They are known for their recalcitrance and circumvention of nearly all the known wastewater treatment procedures. However, the wastewater treatment methods which applied advanced oxidation processes (AOPs) are documented for their successful remediation of POPs. AOPs are a group of water treatment technologies which is centered on the generation of OH radicals for the purpose of oxidizing recalcitrant organic contaminants content of wastewater to their inert end products. Circumvention of the reported demerits of AOPs such as low degradation efficiency, generation of toxic intermediates, massive sludge production, high energy expenditure and operational cost can be done through the application of the combined AOPs in the wastewater treatment procedure. The resultant mineralisation of the POPs content of wastewater is due to the synergistic effect of the OH radicals produced in the combined AOPs. Hydrodynamic cavitation is the application of the pressure variation in a liquid flowing through the venturi or orifice plates. This results in generation, growth, implosion and subsequent production of OH radicals in the liquid matrix. The generated OH radical in the jet loop hydrodynamic cavitation was applied as a form of advanced oxidation process in combination with hydrogen peroxide, iron (II) oxides or the synthesized green nano zero valent iron (gnZVI) for the treatment of simulated textile and pharmaceutical wastewater.
Sable, Shailesh Subhashrao. "Development of novel catalytic materials for removal of emerging organic pollutants by advanced oxidation processes (AOPS)." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/284945.
Full textEl objetivo principal de nuestro trabajo es el desarrollo de nuevos materiales catalíticos y métodos prometedores, eficientes y respetuosos con el medio ambiente para la degradación y la mineralización de contaminantes orgánicos por medio de Procesos de Oxidación Avanzada (POA) para el tratamiento de aguas residuales. Con este propósito, varias familias de catalizadores han sido sintetizados por diferentes métodos y se ha evaluado su actividad catalítica en los procesos de oxidación avanzada de ozonización catalítica y el proceso Fenton heterogéneo, tanto para la eliminación de compuestos farmacéuticos emergentes como el ácido clofíbrico (CFA), como compuestos recalcitrantes de origen industrial, como fenol, en condiciones ambientales. Entre todos los catalizadores estudiados en el proceso de ozonización catalítica, el catalizador de óxido de Cu-Al preparado por un método de co-precipitación, ha mostrado una excelente actividad y estabilidad en la ozonización catalítica de CFA, alcanzando un 82% y 96% de mineralización en 2 y 6 h, respectivamente. En cuanto al proceso Fenton, catalizadores de óxido de Fe conteniendo fases de hematita y maghemita y a los que se le ha añadido pequeñas cantidades de Pd (Pd/FeOOH) han mostrado muy buenos resultados en la eliminación de CFA mediante un proceso Fenton heterogéneo. En el proceso combinado de adsorción+oxidación, la zeolita ZSM5 conteniendo Fe y Pd (Pd/Fe-ZSM5) ha presentado un buen desempeño en la eliminación de fenol mediante adsorción y oxidación por un proceso Fenton heterogéneo.
The main aim of our work is to develop new catalytic materials and promising, efficient and environmental-friendly methods for the degradation and mineralization of organic pollutants by means of Advanced Oxidation Processes (AOPs) for wastewater treatment. For this purpose various families of catalysts were synthesized by different methods and their potential catalytic activity have been evaluated in Advanced Oxidation Processes (AOPs) such as ozonation and Fenton-like process for treating emerging pharmaceutical compounds like clofibric acid (CFA) and recalcitrant compounds like phenol at ambient conditions. Among all the catalysts screened, the Cu-Al oxide catalyst prepared by a co-precipitation method, showed an excellent activity and stability in catalytic ozonation of CFA, achieving 82% and 96% mineralization in 2 and 6h, respectively. As for the Fenton process, catalysts containing Fe oxides presenting hematite and maghemite phases, and to which small amounts of Pd were added (Pd/FeOOH) have shown very good results in the removal of CFA by means of heterogeneous Fenton process. In the combined process of adsorption+oxidation, ZSM5 zeolite containing Fe and Pd (Pd/Fe-ZSM5) has presented good performance in the removal of phenol by adsorption and oxidation by heterogeneous Fenton-like process.
Andrade, Juliano de Almeida. "Otimização da reação de fenton visando aplicações na remediação in-situ e ex-situ de aguas subterraneas." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249632.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Mestrado
Quimica Analitica
Mestre em Química
Wong, Kit Iong. "Chemical removal of dichloromethane (DCM) from contaminated water using advanced oxidation processes (AOPs) :Hydrogen Peroxide Ozone UV." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3868740.
Full textAcar, Ebru. "Oxidation Of Acid Red 151 Solutions By Peroxone (o3/h2o2) Process." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605527/index.pdf.
Full textPeroxone process&rdquo
. The aim of the study is to enhance the ozonation efficiency in treating the waste dye solution. The effects of pH, initial dye and initial ozone concentrations and the concentration ratio of initial H2O2 to initial O3 on color and COD removals were investigated. Also, the kinetics of O3-dye reaction in the presence of H2O2 was approximately determined. As a result of the experimental study, it was seen that an increase in the initial dye concentration at a constant pH and initial ozone concentration did not change the COD % removal significantly, from a statistical analysis of the data. The results obtained at pH values of 2.5 and 7 gave higher oxidation efficiencies in terms of color and COD removals compared to those at pH of 10. The best initial molar ratio of H2O2 to O3 was found to be 0.5, which yielded highest treatment efficiency for each pH value studied. The results of the excess dye experiments suggest that the ozonation of Acid Red 151 follows an average first order reaction with respect to ozone at pH=2.5 and pH=7 whereas it is around 0.56 at pH=10. By Initial Rate Method, the orders with respect to individual reactants of O3 and dye were determined as one, the total order of the reaction being two for all the studied pH. As a conclusion, a further study of the peroxone process at a pH of 10 can be recommended to determine the reaction kinetics and mechanism at this pH, where radicals play an important role.
Filho, Saulo Afonso de Almeida. "Processos oxidativos com hidroperóxidos, persulfatos ou perácidos, catalisados por espécies de cobre e de ferro com potencial aplicação em química ambiental." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-29072015-111500/.
Full textIn this work, iron and copper complexes were synthesized, with imine ligands obtained from 2-acetylpyridine and 2-(2-aminethylpiridine) (apyepy), or 2- acetylpyridine and 2- (aminomethyl)benzimidazole (apyambi) and commercial ligands (nitriletriacetic and picolinic acids) that are able to catalyze the oxidation of pollutant compounds as benzene, , ethylbenzene and xilenes (BTEX). Toluene was used as model compound of those pollutants, and its degradation was verified by using hydrogen peroxide, alkaline peroxide, sodium persulfate, or peracetic acid as oxidant agent. The imine ligands were obtained from adequate carbonyl and amine precursors, in condensation reactions, and the corresponding copper(II), iron(II) and iron(III) complexes were isolated by usual methods developed in our laboratory. Their characterization was carried out by analytical and spectroscopic techniques (UV/Vis, IR and EPR). Those complexes were then inserted in inorganic matrices (niobates) e its reactivity were compared to that of the analogous species in solution. Toluene degradation by hydrogen peroxide was monitored by gas chromatography, and the results showed good catalytic activity of all the complexes, both in solution and inserted into niobate matrices. In solution, the imine complexes were more efficient than the species with commercial ligands. The iron compounds with both imine ligands acted as better catalysts than the corresponding copper species, and for both metals those with the ligand apyepy were the most efficient in both cases. The insertion in niobates apparently preserves the catalyst and maintains its activity for longer, attesting that the insertion ameliorated the process.
Silva, Marcos Erick Rodrigues da. "Tratamento AnaerÃbio de Efluentes Contendo Corantes e Estudos de PÃs-Tratamento e Ecotoxicidade." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5790.
Full textO descarte de efluentes tÃxteis em Ãguas superficiais representa um sÃrio problema ambiental e de saÃde pÃblica devido, principalmente, à presenÃa de corantes na sua composiÃÃo, muitos dos quais sÃo potencialmente tÃxicos e carcinogÃnicos. A remoÃÃo de cor e a mineralizaÃÃo de seus subprodutos à uma das maiores dificuldades enfrentadas pelas estaÃÃes de tratamento de efluentes das indÃstrias desse segmento. Nesta pesquisa, buscou-se avaliar o tratamento de efluentes tÃxteis em sistemas anaerÃbios de um e dois estÃgios, estudar opÃÃes de pÃs-tratamento por processos biolÃgicos aerÃbios e de oxidaÃÃo avanÃada, e utilizar testes de ecotoxicidade no estudo dos diversos efluentes produzidos. Foram realizados experimentos com sistemas anaerÃbios de um (R1) e dois estÃgios (R2) tratando esgotos tÃxteis real e sintÃticos. Nestes experimentos, foram avaliados o efeito da concentraÃÃo do corante, concentraÃÃo do doador de elÃtrons externo, o tempo de detenÃÃo hidrÃulica (TDH) e o efeito do mediador redox antraquinona-2,6-dissulfonato (AQDS) na eficiÃncia de descoloraÃÃo. Outros dois sistemas anaerÃbios de um estÃgio (R3 e R4) foram operados em paralelo, alimentados com esgoto tÃxtil real com TDH de 12h a fim de avaliar o efeito do AQDS na descoloraÃÃo de efluentes reais. Durante o pÃs-tratamento aerÃbio, foi avaliada a aplicaÃÃo de um reator de lodos ativados em batelada seqÃencial com ciclo total de 24h, operando com os efluentes, sintÃtico e real, previamente tratados no reator UASB. Avaliou-se, tambÃm, a aplicaÃÃo do processo de oxidaÃÃo avanÃada (POA) do tipo UV/H2O2 como opÃÃo de pÃs-tratamento dos efluentes tÃxteis tratados no reator UASB, tanto em relaÃÃo à descoloraÃÃo quanto na mineralizaÃÃo dos subprodutos gerados na reduÃÃo dos corantes. A avaliaÃÃo da toxicidade dos efluentes foi realizada pelos ensaios de toxicidade aguda utilizando a Daphnia magna como organismo teste. Os resultados dessa pesquisa revelaram que o sistema anaerÃbio de dois estÃgios mostrou-se mais estÃvel que o sistema de um estÃgio quando operado como o esgoto real e sintÃtico com os corantes Congo Red (CR) e Reactive Black 5 (RB5) e mais eficiente para o corante RR2 na ausÃncia de AQDS. Entretanto, na presenÃa do AQDS a eficiÃncia de descoloraÃÃo do Reactive Red 2 (RR2) foi elevada para os dois sistemas, mascarando o efeito da separaÃÃo de fase. Para o efluente tÃxtil real, nÃo foi verificado efeito algum da aplicaÃÃo do AQDS no R3, mesmo em baixo TDH e limitada concentraÃÃo de doador de elÃtrons. O pÃs-tratamento dos efluentes real e sintÃticos no reator aerÃbio foi capaz de reduzir a DQO abaixo de valor exigido pela portaria 154/02 da SEMACE. O processo de oxidaÃÃo avanÃada com UV/ H2O2 mostrou-se eficaz na remoÃÃo de cor e DQO dos efluentes tÃxtil real e sintÃticos. Os testes de toxicidade aguda ratificaram o potencial tÃxico dos efluentes tÃxteis e os subprodutos de sua degradaÃÃo assim como a capacidade de mineralizaÃÃo das aminas em sistemas seqÃenciais anaerÃbio/aerÃbio.
Disposal of textile effluents in surface waters represents a serious environmental and public health problem mainly due to the presence of dyes in their composition, many of which are potentially toxic and carcinogenic. The color removal and mineralization of byproducts is the major difficulty faced by the wastewater treatment plants of these industries. This thesis studied the treatment of textile effluents in one-stage and two-stage anaerobic systems, post-treatment options by using aerobic biological and advanced oxidation processes, and use the ecotoxicity tests for the various effluents produced. Experiments were performed in one-stage (R1) and two-stage (R2) anaerobic systems treating real and synthetic textile wastewaters. In these experiments, we evaluated the dye concentration effect, as well as external electron donor concentration, hydraulic retention time (HRT) and the redox mediator anthraquinone-2,6-disulfonate (AQDS) effect on color removal efficiency. Two other one-stage anaerobic systems (R3 and R4) were operated in parallel at the HRT of 12 hours and fed with real textile wastewater to assess the AQDS effect on the decolourisation of real textile effluents. During the aerobic post-treatment, we evaluated the application of sequencing batch reactor (SBR) with 24 hours total cycle to treat synthetic and real textile wastewaters pre-treated in the UASB reactor. We also evaluated the application of UV/H2O2 advanced oxidation process (AOP) to treat real textile wastewaters pre-treated in the UASB reactor, both in terms of color removal and mineralization of byproducts generated upon dye reduction. The evaluation of the effluents toxicity was performed by acute toxicity tests using Daphnia magna as test organism. The results revealed that the two-stage anaerobic system was more stable than the one-stage system for both real and the synthetic dyes Congo Red (CR) and Reactive Black 5 (RB5), and more efficient for the dye RR2 in absence of AQDS. However, in the presence of AQDS, color removal efficiency of RR2 was higher for both systems, masking the effect of phase separation. For real textile wastewater, it was not observed any effect of the AQDS application on R3, even when a short HRT or low electron donor concentration was applied. The aerobic and AOP post-treatments were able to reduce the effluents COD to values lower than the limits defined at the Legislation n 154 of SEMACE. The UV/H2O2 AOP-type was effective in removing color and COD from both real and synthetic textile effluents. The acute toxicity tests revealed the toxic potential of textile effluents and their by-products as well as the aromatic amines mineralization in anaerobic/aerobic systems.
Santos, Rodrigo Morais Menezes dos [UNESP]. "Materiais derivados de hidróxidos duplos lamelares: síntese, caracterização e aplicação em adsorção e processos avançados de oxidação." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/132959.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A contaminação de recursos hídricos por diversos poluentes orgânicos, como os corantes têxteis, tem causado sérios problemas ambientais. Alguns processos de descontaminação utilizam materiais sólidos para adsorção/sorção, com características apropriadas para a implantação em escala industrial, apresentando alta eficiência e baixo custo. Os Processos Avançados de Oxidação (AOP), como a fotocatálise heterogênea, também têm sido empregados na descontaminação de águas, convertendo os poluentes orgânicos em substâncias mais facilmente degradáveis, inertes ou inofensivas. Materiais multifuncionais como os Hidróxidos Duplos Lamelares (HDL) e seus derivados se mostram promissores tanto em processos adsortivos como fotocatalíticos. No presente trabalho foi dado enfoque ao processo de adsorção de um azocorante têxtil, utilizando HDL do sistema ZnAl-CO3 e o óxido misto obtido no tratamento térmico a 450°C. Os materiais apresentaram características interessantes e alta capacidade de remoção do corante. As isotermas de adsorção apresentaram boa correlação com o modelo de Langmuir e o cálculo de seus parâmetros revelou que a capacidade máxima adsortiva do material calcinado foi cerca de 6 vezes superior ao material não calcinado, 1587,1 mg⋅g-1 e 261,8 mg⋅g-1, respectivamente. A maior capacidade de adsorção/sorção foi atribuída ao melhoramento das propriedades texturais e ao comportamento da “regeneração” da estrutura HDL pelo precursor calcinado. Os resultados revelaram que o controle cinético do processo é uma etapa de adsorção química, e os parâmetros termodinâmicos calculados mostraram que o processo de adsorção é espontâneo e endotérmico. Os experimentos de conversão fotocatalítica de corante mostraram que os derivados da calcinação dos HDL são materiais promissores para serem utilizados nos AOP. A formação do nanocompósito ZnAl2O4/ZnO no material calcinado a 850°C, mostrou os melhores resultados de conversão, pela estratégia de acoplamento de bandas para separação de cargas, que diminui os problemas relacionados com a recombinação dos portadores de carga, além da maior absorbância no UV. Dessa forma, os resultados obtidos mostram a multifuncionalidade desses materiais, e fornecem novas evidências sobre a reconstrução de HDL pelo “efeito memória”, tópico de intensa discussão na literatura.
The contamination of water resources by several organic pollutants, including textile dyes, which have caused serious environmental problems. Solid materials for adsorption with appropriate features to be employed in industrial scale, such as high efficiency and low cost have been used in some decontamination processes. The Advanced Oxidation Processes (AOP) including heterogeneous photocatalysis, have also been used in water treatment, converting the organic pollutants into easily degradable, inert or harmless substances. Multifunctional materials, such as the Layered Double Hydroxides (LDH) and their derivatives, show potential in both adsorptive and photocatalytic processes. In this work the textile azo dye adsorption process using a ZnAl-CO3 LDH and the mixed oxide obtained from thermal treatment at 450 °C were focused. The materials presented interesting features and high removal capacity for the dye. The adsorption isotherms showed good correlation with the Langmuir isotherm model and the calculated parameters revealed that the maximum adsorption capacity of the calcined material was about 6 times higher than the non-calcined material, 1587.1 mg⋅g-1 and 261.8 mg⋅g-1, respectively. The higher adsorption capacity was assigned to the improvement of the textural properties and to the LDH-structure recovery from the calcined precursor. The results showed kinetic control of the process is a chemical adsorption step, and the calculated thermodynamic parameters showed the adsorption process is spontaneous and endothermic. The dye photocatalytic conversion experiments presented that the derivatives of the LDH calcination are promising materials to be used in the AOP. The formation of a ZnAl2O/ZnO nanocomposite from calcination at 850 °C showed the best conversion results from the coupling semiconductors for charge separation strategy that diminish some problems associated with charge carrier recombination and its higher UV absorbance. Thus, the results show the multi-functionality of these materials, giving some light to the discussion about LDH recovery by "memory effect" that remains a topic of intense debate in the literature.
FAPESP: 2013/25043-4
Gasparini, Mirthys Cozzett. "Águas de processo da REPLAN = qualidade e aplicação de processos oxidativos avançados." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257779.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: No presente trabalho foi realizada a caracterização de várias correntes de águas de processo da REPLAN (Refinaria de Paulínia), bem como a avaliação dos processos de fotólise (UV), peroxidação (H2O2), peroxidação assistida por radiação ultravioleta (H2O2/UV), reagente de Fenton (H2O2/Fe2+) e foto-Fenton (H2O2/Fe2+/UV) no tratamento de um dos efluentes, principalmente na degradação dos compostos orgânicos. Analisando-se os dados de caracterização dos diferentes efluentes foi possível sugerir alternativas de reuso no processo de refino, como também selecionar a corrente de água ácida retificada para aplicação dos processos físico-químicos de tratamento. A eficiência dos ensaios de tratabilidade foi baseada na redução da concentração do carbono orgânico dissolvido (COD). Dentre os processos estudados, os processos oxidativos avançados (POA) H2O2/UV e foto-Fenton apresentaram 95 % de eficiência após 150 minutos de ensaio. As condições ótimas foram obtidas na relação mássica COD: H2O2 de 1:7 para o processo peroxidação assistida por radiação UV, e de 1:5 e concentração de Fe2+ de 31 mg/L para o processo foto-Fenton. O efluente tratado pelo processo H2O2/UV poderia ser reutilizado como água de reposição no sistema de resfriamento, já que esta é responsável por 49 % do total de água utilizada na refinaria
Abstract: In the present study was performed the characterization of various process water from REPLAN (Paulínia Refinery) as well as an assessment of 5 processes to treat one of the effluents: photolysis (UV), peroxidation (H2O2), peroxidation assisted by ultraviolet radiation (H2O2/UV), Fenton reagent (H2O2/Fe2+) and photo-Fenton (H2O2/Fe2+/UV), in order to degrade the organic compounds. Effluents characterization results provided reuse possibilities in the process refining and also selected the stripped sour water stream for application of physical-chemical treatments. The processes efficiency was evaluated by the dissolved organic carbon (DOC) reduction. Among the processes studied, the advanced oxidation processes (AOPs) H2O2/UV and photo-Fenton reached 95 % efficiency after 150 minutes of reaction. The optimum conditions were obtained in a mass ratio COD: H2O2 of 1:7 for peroxidation assisted by UV radiation, and of 1:5 with 31 mg/L of Fe2+ for photo-Fenton. The effluent treated by AOP H2O2/UV could be reused as make-up water in cooling systems, since it is responsible for 49 % of the total water used in the refinery
Mestrado
Saneamento e Ambiente
Mestre em Engenharia Civil
Matysíková, Jana. "Znovu-užití vyčištěných odpadních vod v papírenském a textilním průmyslu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225374.
Full textPirgalioglu, Saltuk. "Catalytic Ozonation Of Dye Solutions In A Semi-batch Reactor." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12610158/index.pdf.
Full textMetolina, Patrícia. "Degradação do antibiótico bacitracina zíncica em meio aquoso através de processos oxidativos avançados." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-24092018-082606/.
Full textThe presence of antibiotics in ecosystems represents a serious risk to human and animal health, caused by the increase in bacterial resistance. Since most antibiotics resist to biological degradation, advanced oxidation processes are pointed out as the most effective technologies for degrading these compounds in wastewater. Zinc bacitracin (Bc-Zn) is a potent antibiotic with a complex mixture of non-biodegradable peptides conjugated to zinc. Despite being a widely used antibiotic in human and animal medicine, the scarcity of studies dealing with its degradation and environmental fate is a matter of concern. In this work, Bc-Zn degradation by direct photolysis and the UV/H2O2 process was investigated for different UVC radiation conditions and initial H2O2 concentrations. Kinetic parameters, namely the photolysis quantum yield, pseudo-first order kinetic constants and second-order kinetic constants, were satisfactorily estimated from experimental data by modeling the photochemical system. The results showed that all the congeners of the Bc-Zn mixture were photolyzed at the highest UVC doses applied, while no TOC removal was observed after 120 minutes of irradiation. The addition of H2O2 substantially accelerated Bc-Zn photodegradation, with pseudo-first order kinetic constants of one order of magnitude higher than those observed under direct photolysis. In addition, a remarkable removal of up to 71% of TOC was achieved. Statistical analyses showed that UV radiation had a much more important effect on Bc-Zn photodegradation in comparison with initial H2O2 concentration, with the best process conditions achieved for the highest specific photon emission rate (1.11×10-5 Einstein L-1 s-1). Biological assays carried out with the solutions treated by direct photolysis and UV/H2O2 revealed no residual antimicrobial activity, though photodegradation products remained non-biodegradable. In addition, toxicity analyses indicated that the zinc metal present in the antibiotic is responsible for the toxic effect on the test microorganism Vibrio fischeri. Finally, further studies should be performed to identify the by-products formed and to investigate Bc-Zn degradation in real industrial wastewater.
Oliveira, Clélia Aparecida da Silva 1972. "Tratamento de corante têxtil por eletrólise, fotólise e fotocatálise utilizando LED UV = Treatment of textile dye by electrolytic, photolytic and photocatalytic processes." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267750.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
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Resumo: A indústria têxtil gera elevados volumes de efluentes com alta carga orgânica e compostos recalcitrantes, os quais são tratados por sistemas baseados em processos físicos, químicos e biológicos convencionais. Entretanto, o caráter não destrutivo dos tratamentos convencionais representa um sério problema no setor. Nos últimos 20 anos, os Processos Oxidativos Avançados (POA) têm estado em evidência devido à sua capacidade em degradar inúmeros compostos orgânicos contidos em águas e efluentes. Uma grande quantidade de trabalhos utilizando luz UV a partir de lâmpadas de vapor de mercúrio tem resultado em elevada eficiência de degradação de substratos recalcitrantes incluindo efluentes têxteis; entretanto, demandam elevado consumo de energia elétrica, encarecendo o tratamento. Em contrapartida, o surgimento de Diodos Emissores de Luz Ultravioleta (LED UV) abre novas fronteiras de aplicação no campo de tratamento de águas residuárias, quanto a custo, operacionalidade e tamanho dos sistemas. Nesse trabalho estudou-se a degradação de um efluente têxtil simulado contendo o corante Remazol Azul Brilhante (C.I. Reactive Blue 19) através de processos eletroquímicos e fotoeletroquímicos que utilizam LED UV, utilizando-se dois reatores: um operando em batelada contendo o fotocatalisador TiO2 e o outro, em fluxo, contendo um cátodo (tela cilíndrica de aço-inoxidável), um tubo de quartzo contendo os LED UV e o Anodo Dimensionalmente Estável (ADE 70%TiO2/30%RuO2). Os resultados demonstraram que, no reator de bancada, a eficiência de remoção de cor foi de 100% para concentração inicial de 50 mg L-1 do corante, em 24 horas de tratamento. No reator em fluxo, utilizando Na2SO4 como eletrólito, o processo eletrolítico resultou em eficiência de 65%; o fotoeletrocatalítico, em 68%, operando a 750 L h-1 e em 57,3 mA cm-2. Quando foi utilizado o eletrólito NaCl, obteve-se remoção de 100% da cor em 5 minutos de tratamento a 750 L h-1, independente da concentração inicial do corante utilizada (50 mg L-1 ou 100 mg L-1), da concentração do eletrólito (0,05 M ou 0,1 M), da densidade de corrente (14,3 mA cm-2 , 28,7 mA cm-2 ou 57,3 mA cm-2) e do processo utilizado
Abstract: The textile industry generates large amount of wastewater containing significant organic load and recalcitrant compounds, which in most cases are treated by conventional systems involving physical, chemical and biological processes, the latter represented mainly by activated-sludge treatment. However, the non-destructive profile of conventional treatments is a serious problem for textile-based industry. Over the past 20 years, the study of Advanced Oxidation Processes (AOP) has been carried out due to its high capacity degradation of numerous organic pollutants contained in waters and wastewaters. Research using UV light from mercury vapor lamps usually has resulted in high efficiency degradation of recalcitrant substrates including textile effluents but requires high electrical power consumption besides other drawbacks. In contrast, the emergence of Ultraviolet Light Emitting Diodes (UV LED) opens new perspectives for application on wastewater treatment, concerning efficiency, footprint and costs of the systems. In this work we studied the degradation of a simulated wastewater containing a textile dye, Remazol Brilliant Blue (C.I. Reactive Blue 19) through electrochemical and photoelectrochemical processes using UV LED as ultraviolet radiation source. The experimental apparatus consisted of two systems: the first, a bench-scale reactor containing TiO2 photocatalyst (P25 DEGUSSA) in solution, and another pilot-scale system operated in batch recirculation mode composed of an tubular stainless-steel screen cathode, a quartz tube containing the UV LED and a oxide-coated titanium anode (DSA©30%TiO2/70%RuO2). The results showed total decolorization of a solution containing 50 mg L-1 of RB in 24-hour treatment in the bench-scale reactor. Tests on flow reactor using Na2SO4 as supporting electrolyte resulted in 65% of color removal using electrolytic process and 68% for photoelectrocatalytic process operating at 750 L h-1 and 57.3 mA cm-2. In experiments using the electrolyte NaCl it was obtained 100% in the color degradation within 5 minutes of treatment at 750 L h-1, regardless of the: initial concentration of dye used (50 mg L-1; 100 mg L-1), concentration of the electrolyte (0.05 M; 0.1 M) and current density value (14.3; 28.7; 57.3 mA cm-2)
Mestrado
Tecnologia e Inovação
Mestra em Tecnologia
Fujimoto, Tânia Miyoko 1985. "Oxidação de compostos orgânicos voláteis em fase gasosa por fotocatálise heterogênea com TiO2 e TiO2/Pd." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266077.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Compostos orgânicos voláteis (COV) representam uma categoria de substâncias poluentes que geram diferentes impactos ambientais. Eles são responsáveis pelo aumento das concentrações de ozônio ao nível do solo e pela formação de aerossóis orgânicos secundários. Além disso, alguns deles contribuem para a degradação do ozônio estratosférico e a ampliação do efeito estufa. Alguns componentes têm um caráter carcinogênico, teratogênico ou mutagênico. Há estudos envolvendo o tratamento dos COV pelos mais diversos métodos, tais como: incineração, adsorção e absorção. Reatores fotocatalíticos, muito estudados em aplicação em fase aquosa e com grande sucesso na oxidação de contaminantes orgânicos, aparecem como uma alternativa pouco estudada. A fotocatálise em fase gasosa usando o TiO2 como catalisador se apresenta como uma solução interessante para o tratamento de compostos orgânicos voláteis, por não requerer operação em altas temperaturas, pelo baixo custo do TiO2, por ser seletiva na absorção de radiação e por gerar como produtos da reação CO2 e água, o que dispensa demais tratamentos. Estudos demonstram que a adição de metais nobres ao TiO2 comprova uma melhoria na eficiência fotocatalítica das reações de oxidação de compostos orgânicos voláteis. Dentro deste escopo, este trabalho tem como objetivo testar a eficiência do processo de oxidação de COV em fase gasosa por fotocatálise heterogênea com catalisador de dióxido de titânio (TiO2) impregnado com 1% de paládio (Pd) sob luz ultravioleta. O método de impregnação de paládio em TiO2 pela redução com NaBH4 mostrou-se adequado pelas técnicas de caracterização por DRX, XPS, UV ¿Vis, BET, MEV e Quimissorção de H2, pois há a impregnação do metal na superfície do catalisador sem promover modificações estruturais no TiO2 e não ocorreu alterações na razão de anatase/rutilo. Por XPS indicou a presença de metal em sua forma elementar. Além disso, os resultados da oxidação dos compostos n-hexano, ciclohexano, metil-ciclohexano, n-octano e iso-octano demonstraram aumento significativo na eficiência da conversão, pois foram obtidos valores acima de 90% em tempos de residência de aproximadamente 35 s
Abstract: Volatile organic compounds (VOCs) represent a category of pollutants substances that generate different impacts. They are responsible for increase concentrations of tropospheric ozone and also the formation of secondary organic aerosols. In addition, some of them contribute to the degradation of stratospheric ozone and greenhouse gas intensification. Some components have a carcinogenic, teratogenic or mutagenic character. There are studies involving the treatment of VOCs with various methods, such as: incineration, adsorption and absorption. Photocatalytic reactors, extensively studied in aqueous and with great success to destroy organic contaminants, appears as an alternative understudied. The photocatalysis gas phase using TiO2 as catalyst shows an interesting solution for the treatment of volatile organic compounds, because does not require operation at high temperatures, the low cost of TiO2, being selective in absorbing radiation and the products of reactions are CO2 and water, which eliminates other treatments. Studies prove that the addition of noble metals on TiO2 can improve the photocatalytic efficiency in the oxidation of volatile organic compounds. Therefore, this paper aims to test the efficiency of oxidation of volatile organic compounds (VOC) in gas phase catalysts through heterogeneous photocatalysis with titanium dioxide (TiO2), and their impregnation with 1% palladium (Pd) and UV light. The method for impregnate palladium on TiO2 with NaBH4 reduction was appropriated according to techniques for characterization like XRD, XPS, UV-vis, BET, SEM and H2 chemisorption, because all analysis confirmed that the impregnation of the metal on the catalyst surface do not structurally modify TiO2, neither changes occurred in the ratio of anatase/rutile. XPS indicated the presence of metal in elemental form. The results the oxidation of compounds n-hexane, cyclohexane, methyl cyclohexane, n-octane and iso-octane indicated a significant increase in conversion efficiency; the values were above 90% at residence times around 35 s
Mestrado
Desenvolvimento de Processos Químicos
Mestra em Engenharia Química
Nogueira, Maria Ionete Chaves. "Tratamentos adsortivos e de oxidaÃÃo avanÃada de fenol, 2-nitrofenol e 4-nitrofenol em soluÃÃo aquosa." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=4106.
Full textNeste trabalho foram realizados estudos de adsorÃÃo em batelada e de oxidaÃÃo avanÃada para a remoÃÃo de fenol (F), 2-nitrofenol (2NF) e 4-nitrofenol (4NF) em soluÃÃo aquosa. Nos estudos de adsorÃÃo foram empregados como adsorventes o pà de bagaÃo da casca de coco in natura (BIN), pà de bagaÃo in natura tratado com HCl 1,0 M (BT) e carvÃo ativado (CA) proveniente da carbonizaÃÃo a 250ÂC do pà de bagaÃo tratado com Ãcido. Experimentos de equilÃbrio e cinÃtica de adsorÃÃo foram realizados nas temperaturas de 28, 40 e 50ÂC. Isotermas de Langmuir e Freundlich correlacionaram bem os dados de equilÃbrio, indicando capacidades de adsorÃÃo (qmÃx) que aumentaram na ordem: CA >>> BT > BIN. Este comportamento denota uma adsorÃÃo caracterizada pelas interaÃÃes entre os elÃtrons dos anÃis aromÃticos e os elÃtrons das camadas grafÃticas do carvÃo, a qual à mais intensa que a verificada nos materiais celulÃsicos onde predomina a formaÃÃo de complexos doador-receptor entre os sÃtios oxigenados localizados na superfÃcie do adsorvente e o anel aromÃtico dos compostos fenÃlicos. Os melhores resultados de qmÃx em carvÃo ativado e pà de bagaÃo tratado com Ãcido foram obtidos para a adsorÃÃo de 2-nitrofenol à temperatura ambiente (28ÂC), correspondentes aos valores de 17,1 e 1,39 mg/g, respectivamente. Do ponto de vista cinÃtico o modelo de pseudo-segunda ordem apresentou melhor ajuste dos dados experimentais. Por outro lado, processos oxidativos avanÃados (POAs) das molÃculas fenÃlicas foram conduzidos para os tratamentos fotolÃtico (UV), fotoquÃmico (UV/H2O2), Fenton (Fe2+/H2O2) e eletroquÃmico com anodos dimensionalmente estÃveis (ADEs) de Ru0,3Ti0,7O2, Ru0,3Ti0,4Sn0,3O2 e Ru0,3Sn0,7O2. Os processos Fenton e fotoassistidos apresentaram condiÃÃes Ãtimas nas concentraÃÃes de 1,0 mM em Ãons Fe2+e 3,0 mM em H2O2 e taxa de radiaÃÃo (I0) de 64 mW/cm2. Os Ãxidos eletrocatalÃticos foram preparados por termodecomposiÃÃo de cloretos precursores a 500oC atà a formaÃÃo de filmes com 2,0 Âm de espessura sobre um suporte de titÃnio. A caracterizaÃÃo pelas tÃcnicas de EDX, MEV e Voltametria CÃclica mostrou composiÃÃes praticamente estequiomÃtricas, morfologia estrutural tipo cracked mud e elevado sobrepotencial para a reaÃÃo de desprendimento de oxigÃnio (RDO). Estudos de oxidaÃÃo para as molÃculas fenÃlicas mostraram o 2-nitrofenol como a espÃcie mais oxidÃvel e o fenol comum como a espÃcie menos reativa. As eficiÃncias de degradaÃÃo dos processos fotoassistidos foram particularmente elevadas (superiores a 80%) enquanto o sistema Fenton apresentou taxas de remoÃÃo entre 60 e 78%. A modelagem cinÃtica segundo o modelo de pseudo-primeira ordem adotado permitiu um bom ajuste dos dados experimentais. Os valores da constante cinÃtica 1/ (min-1) a 28ÂC mostraram a seguinte ordem: Fenton (8,16 min-1) > fotoquÃmico (6,95 min-1) >> fotolÃtico (1,98 min-1). Em adiÃÃo, estudos usando anodos eletrocatalÃticos (ADEs) a potencial constante de eletrÃlise de 2,0 V mostraram degradaÃÃes superiores a 93% para os nitrofenÃis e entre 65 e 86% para o fenol. Em termos, considerado o tipo de ADE empregado, a eficiÃncia de eletrooxidaÃÃo à temperatura ambiente obedece a seguinte ordem de eficiÃncia: Ru0,3Ti0,7O2 > Ru0,3Ti0,4Sn0,3O2 > Ru0,3Sn0,7O2. A anÃlise espectroscÃpica para identificaÃÃo de co-produtos indicou completa mineralizaÃÃo dos compostos fenÃlicos nos processos fotoquÃmico e eletroquÃmico, enquanto que nos processos Fenton e fotolÃtico foram detectados traÃos de produtos hidroxilados. Em geral, os resultados obtidos confirmam os processos adsortivos e oxidativos como tratamentos promissores para a despoluiÃÃo de sistemas aquosos contendo fenÃis e nitrofenÃis
In the present work the batch adsorption and advanced oxidation of phenol (F), 2-nitrophenol (2NF) and 4-nitrophenol (4NF) in aqueous phase has been studied. The adsorption experiments were conducted onto coconut shell powder (BIN), coconut shell powder treated with HCl 1.0M (BT) and coconut shell-based activated carbon (CA) obtained from carbonization at low temperature (250ÂC). Equilibrium and kinetic studies were carried out at temperatures of 28, 40 and 50ÂC. Langmuir and Freundlich isotherms correlated well the equilibrium data, indicating the adsorption capacity (qmax) increased in the order: AC>>> BT> BIN. This behavior denotes an adsorption characterized by dispersive interactions between the -electrons of the graphitic carbon basal planes and those of the aromatic rings of the adsorbate, which is more intense when compared to the cellulose materials where are dominant the donor-acceptor complex formation between the oxygenated sites onto adsorbent and aromatic rings of phenol compounds. The best results of qmax in activated carbon and coconut shell powder treated with acid were obtained for the adsorption of 2-nitrophenol at room temperature (28ÂC), corresponding to values of 17.1 and 1.39 mg/g, respectively. In all cases, the adsorption kinetics could be satisfactorily fitted by a pseudo-second order model. Advanced oxidation processes (AOP) were carried out for treatments such photolytic (UV), photochemical (UV/H2O2), Fenton (Fe2+/H2O2) and electrochemical oxidation with dimensionally stable anodes (DSA) type Ti/Ru0.3Ti0.7O2, Ti/Ru0.3Ti0.4Sn0.3O2 and Ti/Ru0,3Sn0,7O2. The Fenton and photoassisted tests were performed to optimized conditions of 1.0 mM of Fe2+ ions, 3.0 mM of H2O2 and radiation intensity (I0) of 64 mW/cm2. Particularly, electrocatalytic oxides were prepared by thermal decomposition of chloride precursors to 500oC until the formation of films with thickness constant of 2μm on titanium support. The characterization by EDX, SEM and Cyclic Voltammetry techniques showed a nearly stoichiometric composition, morphology type âcracked mudâ and elevated overpotencial from oxygen evolution reaction (OER). Degradation efficiencies in photoassisted processes were particularly high (> 80%) while in the Fenton system this values ranged between 60 and 78%. The kinetic modelling using the equation of pseudo-first order adopted allowed a good fit of experimental data. The values of kinetic constant 1/ (min-1) at room temperature showed the following order: Fenton (8.16 min-1) > Photochemical (6.95 min-1) >> photolytic (1.98 min-1). In addition, studies using the electrocatalytic anodes at constant potential electrolysis of 2.0 V showed almost total degradation for the nitrophenols (> 93%) and moderate removal efficiencies for phenol (between 65 and 86%). In terms, considered the type of anode employed the electrooxidation efficiency at room temperature increase in the following order of reactivity: Ru0.3Ti0.7O2 > Ru0.3Ti0.4Sn0.3O2 > Ru0.3Sn0.7O2. Thus, the results confirm the applicability of adsorption and advanced oxidation processes as promising treatments in the remediation of aqueous systems containing phenol and nitrophenols
Acosta, Arlen Mabel Lastre. "Processos de tratamento não convencionais para degradação do antibiótico sulfadiazina em meio aquoso." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-22082016-102752/.
Full textThe potential impacts of antibiotic residues in the environment have become an emerging concern during recent years due to their relation with the development of resistant bacteria, and in some cases to their ability to cause toxic and endocrine disrupting effects in humans and other living organisms. Highlighted among the commonly used antibiotics are the sulfonamides, detected in groundwater and surface water. Advanced oxidation processes (AOP) might constitute an important alternative to deal with pharmaceuticals degradation. Among them, the photo-Fenton process has been widely used. One of its major drawbacks is the highly acidic pH needed (2,5-4,0) to avoid the formation of photochemically inactive iron oxides and hydroxides. The ability of soluble bio-organic substances (SBO) to complex metal cations such as iron is useful for the development of photo-Fenton at mild acidic conditions (pH 5). In turn, the use of ultrasonic energy has been less studied. In this context, the aim of this work is to study the degradation of the antibiotic sulfadiazine (SDZ) by the photo-Fenton process in the presence of soluble bio-organic substances (UV-vis/Fe3+/H2O2/SBO) and by ultrasonic cavitation (US). The results confirm that SDZ is effectively degraded by highfrequency ultrasound. Higher SDZ percent removals and removal rates were observed for the lowest operating frequency (580 kHz), higher dissipated power, and in slightly acidic solution (pH 5.5). On the other hand, SDZ degradation is highly improved in the case of the US/ Fe(II)/H2O2 system. The use of the SBO as Fenton additives in turn has a remarkable influence in SDZ photodegradation at slightly acid conditions (pH 5). This could be ascertained to the complexation of iron by the SBO, hence maintained in the reaction medium as a photoactive species. Under the studied conditions, the BOS CVT230 was more efficient than FORSUD, probably due to differences in the functional groups present in the composition of these substances. Finally, the figures-of merit electrical energy per order (EEO) and collector area per order (ACO) were calculated for the ultrasound (1572 kW h m-3 ordem-1) and photo-Fenton (8,07 m2 m-3 ordem-1) processes respectively.
Baptistucci, Cíntia Bardauil. "Degradação do antibiótico ciprofloxacina em solução aquosa por meio de processo oxidativo avançado baseado em ozônio." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-03052012-122334/.
Full textConventional wastewater treatment processes are not generally efficient for the degradation of persistent substances like pharmaceutical compounds. In this work, the treatment of aqueous solutions containing the antibiotic ciprofloxacin (CIP) by means of the ozone-based advanced oxidation process is studied. With this aim, experiments were carried out in semi-batch mode with liquid circulation in a bubble column reactor with gas-liquid counter flow. Liquid samples were analyzed for CIP and total organic carbon (TOC) concentrations; ozone concentration in the gas was measured by UVvisible spectrophotometry. The effects of the following variables on CIP degradation were studied according to a Doehlert experimental design: inlet ozone concentration (8 to 25 mgO3 L-1), pH (3.5 to 10.5), initial CIP concentration (5 to 26 mg L-1). The following dependent variables were investigated by response surface analysis: variation in CIP concentration after 2 minutes; CIP initial degradation rate and variation in TOC concentration after 30 minutes. The results showed total degradation of ciprofloxacin in less than 15 minutes either by direct reaction with molecular ozone in acidic medium, or by indirect attack of hydroxyl radicals in alkaline medium. Compounds resulting from CIP degradation showed to be recalcitrant, yielding larger TOC removals after 30 minutes only in alkaline or neutral medium (maximum of 72.8% for pH=7, [O3]=24.9 mgO3 L-1, and [CIP]0=15.8 mg L-1). Despite the persistence of remaining organic compounds, respirometric assays suggested that degradation products are less toxic than the parent compound, exhibiting lower inhibition of microbial activity. Overall, the results indicate that the ozonation process can be used in the pre-treatment of aqueous effluents containing ciprofloxacin in low concentrations, and could be associated with biological treatment processes in wastewater treatment plants prior to final disposal.
D\'Avila, Alexandre Coelho da Silva. "Degradação do pesticida amicarbazona em meio aquoso pelo processo TiO2/UV irradiado por luz solar." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-03072013-105850/.
Full textAdvanced oxidative processes (AOP) have been considered as an efficient alternative for the degradation of recalcitrant pollutants. Photocatalysis using solar radiation has been studied for the treatment of wastewaters containing pesticides. In this work, the degradation of the herbicide amicarbazone (AMZ) by the TiO2/UV process was studied in a reactor equipped with compound parabolic collectors irradiated by solar light. The experiments were carried out according to a Doehlert matrix to study the effects AMZ initial concentration (20-100 mg L-1), catalyst concentration (0.1-1 g L-1), and number of tubes exposed to solar light (1-9). Samples were analyzed for AMZ and total organic carbon (TOC) concentrations. Radiometric measurements indicated that UVB-UVA radiation corresponded in average to about 4% of the solar radiation between 310-2800 nm; ferrioxalate actinometry resulted in an average photonic flux of 3.58×10-5 mol fótons m-2 s-1 for typical sunny days. The TiO2/UV process showed to be efficient for the degradation of the pesticide, which was completely removed before 45 minutes of treatment, for the following conditions: [AMZ]0=21.3 mg L-1; [TiO2]=0.5 g L-1; and 7 tubes. However, in this case only ca. 24% of mineralization was achieved, and in most cases TOC values remained practically constant, indicating the formation of recalcitrant by-products whose toxicity and biodegradility should be characterized. Statistical analysis of the results confirmed important effects of pesticide initial concentration and number of tubes exposed (irradiated volume), whose increase enables to compensate the lower incidence of solar radiation. Some experimental results suggested that AMZ degradation was favored by higher TiO2 concentrations. In most cases the values of ACM were lower than 50 m2 kg-1, in such a way that this parameter is interesting for scale-up of solar irradiated photocalytic processes used in the treatment of amicarbazone-containing wastewaters.
Ferrando, Climent Laura. "Analysis of chemotherapy drugs and related compounds in aquatic environment: removal, transformation and risk evaluation in eco-friendly and advanced technologies." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/400719.
Full textPer tal d'avaluar l'augment de risc ambiental i humà de medicaments contra el càncer en el medi ambient, més informació necessita ser recopilada sobre la seva presència, la seva toxicitat, bioacumulació i persistència. A més, la seva capacitat d'eliminació d'aigües residuals en plantes de tractament convencionals i en tractaments alternatius necessita a investigacions addicionals. L'objectiu d'aquesta tesi és omplir els buits de coneixement i proporcionar eines per a una millor avaluació de la presència i el destí dels medicaments contra el càncer en el cicle urbà de l'aigua. El treball presentat per aquest mitjà inclou tres objectius principals: i) desenvolupar metodologies analítiques per a la meta i anàlisi que no són objecte de medicaments contra el càncer a medi aquàtic, ii) per avaluar l'ocurrència de medicaments contra el càncer en els sistemes urbans i iii) per avaluar diferents alternatives tecnològiques a eliminar medicaments contra el càncer d'efluents contaminats
Abouzlam, Manhal. "Optimisation d'un procédé de traitement des eaux par ozonation catalytique." Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2251/document.
Full textThe main goal of the PhD thesis focuses on the optimization of an advanced oxidation process by implementing the modern control tools.The considered process is a lab-scale pilot of industrial wastewater treatment by catalytic ozonation. The optimization of this process is achieved by controlling the pollutant abatement while minimizing the high operating costs. The online measurement of the pollutant concentration is provided by the absorbance which is correlated with COD. Therefore, the process is considered as a system with one input, the ozone generator power, and two outputs, the ozone gas concentration at the top of the reactor and the absorbance.A linear model of the process was identified. It allowed calculating the control laws. And a nonlinear model, with a so-called Wiener model structure, was also identified to test the controllers in simulation before the experiments.The three control methods applied, the internal model control, the optimal control and the H∞ control, allow rejecting disturbance on the pollutant concentration of the effluent to be treated.The stability of closed-loop system with delayed control input was analyzed.The experimental results show the significant benefits provided by this closed-loop system.The methodology developed for this application can be extended to other processes to facilitate the industrial development of advanced oxidation processes
Autin, Olivier. "Micropollutant removal by advanced oxidation processes." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7883.
Full textMirjana, Petronijević. "Uticaj oksidacionih procesa na bazi ozona, vodonik-peroksida i UV zračenja na sadržaj i reaktivnost prirodnih organskih materija u vodi." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2019. https://www.cris.uns.ac.rs/record.jsf?recordId=110672&source=NDLTD&language=en.
Full textThe aim of the research of this PhD thesis was to determine the effects of various oxidation processes based on ozone, hydrogen peroxide and UV irradiation on the content and reactivity of natural organic matter (NOM) in different water matrices. The tests were carried out on a) groundwater from the territory of Kikinda and Temerin (natural matrix) and b) synthetic aqueous matrix (solution of commercially available humic acid), which differ in the composition and structure of NOM present and the content of bromide. For the oxidation process (ozonation, UV photolysis, oxidation with H 2O2 , combined O 3 /UV process and combined H 2O2 /UV process), the influence of different doses of oxidants and reaction conditions was examined individually. Particular attention was paid to the influence of the above treatment on the formation of inorganic bromate, as well as the effect on the content of precursors of disinfectant by-products after chlorination (THM, HAA, HAN, HK and CP).Analysis of the chemical parameters of the synthetic matrix (5.44±0.30 mg C/L; 0.255±0.015 cm -1 ; 4.68±0.41 lm -1 mg -1 ) shows that the high-hydrophobic humic compounds predominate in this water. Also, high NOM content of predominantly hydrophobic character was recorded in Kikinda water (5.170.72 mg C/L; 0.2010.001 cm -1 ; 3.88±0.70 lm -1 mg -1 ), while NOM content in raw water from Temerin (2.060.38 mg C/L; 0.0500.001 cm -1 ; 2.43±0.21 lm -1 mg -1 ) significantly lower and predominate NOM of hydrophilic character. A higher degree of hydrophobicity of the synthetic matrix in comparison with natural matrices, resulted in higher reactivity of organic matter with chlorine, which can be concluded on the basis of high PFDBP values after chlorination. The PFTHM value in the synthetic matrix was 544±85.9 µg/L, while the PFTHM in the raw waters from Kikinda and Temerin was significantly lower (279±32.3 and 180±44.0 µg/L, respectively). The PFHAA value in the synthetic matrix was 484±77.5 µg/L, while PFHAA in the Kikinda water was 223 244±11.1 µg/L and in the Temerin water was 165±32.5 µg/L. The content of precursors of HK (8.05±3.63 µg/L synthetic matrix; 14.91.38 µg/L Kikinda; 7.400.25 µg/L Temerin) was significantly lower compared to precursors of THMs and HAAs, while precursors of HANs and chloropicrin were not detected in raw water. The by- products that were predominantly formed in all the tested water matrices were chlorinated THMs and HAAs, while the brominated DBPs were formed at substantially lower concentrations. The presence of brominated DBPs in Temerine water were significantly higher compared to Kikinda water as a result of the presence of higher bromide content in raw water (0.05±0.01 mg Br -/L Temerin; 0.03±0.01 mg Br -/L Kikinda). By examining the influence of oxidation processes (UV photolysis, ozonation,hydrogen peroxide oxidation) on the content and reactivity of NOM in the tested water matrix, it was found that the UV irradiation and treatment by hydrogen peroxide, when used as an independent treatment, did not show significant efficacy in reducing the NOM content. Water treatment by ozone proved to be very effective in eliminating NOM and reducing the content of DBP precursors in all tested water matrices, as a result of the reduction of NOM reactivity to the formation of these DBPs. Reduction of NOM content in water during treatment increased with increasing the applied dose of ozone, with the best results achieved at the highest dosage of 3.0 mg O 3/mg DOC (up to 32% DOC, 92% UV 254 synthetic matrix, up to 17% DOC, 76% UV 254 Kikinda, up to 15% DOC and 66% UV254 Temerin). In the synthetic matrix the highest reduction in PFTHM (76%) and PFHAA (by 80%) compared to raw water content was achieved at a dosage of 1.0 mg O 3/mg DOC. The highest reduction in PFTHM (38%) and PFHAA (42%) in Kikinda water was achieved at a dose of 3.0 mg O3 /mg DOC. In Temerin water, the highest reduction in PFTHM (27%) was at a dose of 3.0 mg O 3/mg DOC, while the dose of 1.0 mg O3 /mg DOC was best shown for removing PFHAA (by 54%). The content of the precursors of HKs and HANs (Temerin water) was very low after treatment. Water treatment by ozone led to the formation of DBPs with more substituted bromine atoms, while in waters with a mean bromide content (50 μg Br -/L) led to bromate formation.Combination of ozonation with UV irradiation can greatly accelerate the effectiveness of NOM removal achieved by the use of ozonation alone. The highest reduction in NOM content in the synthetic matrix (by 85% DOC, 98% UV 254 and 87% SUVA), in Kikinda water (by 23% DOC, 83% UV 254 , 77% SUVA) and water from Temerin (by 15% DOC, 80% UV 254 and 75% SUVA), compared to the values in raw water, was achieved at the highest dose of 3.0 mg O 3 /mg DOC and 6000 mJ/cm 2 . The efficiency of the process was growing in the waters where NOM predominates of hydrophobicity. Although the O 3 /UV process achieved a high degree of reduction in PFTHM in the synthetic matrix the ozonation (1.0 mg O3 /mg DOC) was proved as more efficient, while the highest reduction in PFHAA (82%) was achieved at a ozone dose of 1.0 mg O 3/mg DOC and UV irradiation of 6000 mJ/cm 2 . In the water from Temerin, in case to removal of precursors of THM and HAA, ozonation was proved to be an optimal process. High alkalinity of natural waters inhibits the radical mechanism during AOP and favors NOM oxidation with molecular ozone. HKs precursors were formed at very low concentrations and their content did not vary significantly during the treatment. In natural matrices during the AOP at a ozone dose of 3.0 mg O3 /mgDOC, HANs were formed, however, there was no clear trend with increasing UV irradiation. The treatment contributed to the formation of brominated THM species, while during the AOPs, brominated HANs were formed at the maximum dose of ozone of 3.0 mg O3/mg DOC. 224 The largest decrease in NOM content by the combination of oxidation with H2O2 and UV irradiation in the synthetic matrix (for up to 17% DOC, 70% UV 254 ), in Kikinda water (up to 22% DOC, 53% UV 254), and water from Temerin (7% DOC, 68% UV 254 ), compared to the values in raw water, were obtained at a dose of H 2O2 and UV irradiation of 3.0 mg O3 /mg DOC and 6000 mJ/cm 2 . The highest PFTHM reduction of 54% in the synthetic matrix was achieved at a dosage of 1.0 mg H2O2/mg DOC and 6000 mJ/cm 2 , while a decrease in PFHAA (35%) was achieved using a dose of hydrogen peroxide and UV irradiation of 1.0 mg H2O2/mg DOC and 3000 mJ/cm 2 . In the water from Kikinda, the H2O2 /UV process did not significantly affect on the THM precursors content, while the highest reduction in PFHAA (35%) was achieved at a dose of 3.0 mg H2O2/mg DOC and 600 mJ/cm 2 . The H 2O2 /UV process led to a decrease in PFTHM in the Temerin water by 74% at a dose of 3.0 mg 2O2 /mg DOC and 600 mJ/cm 2 , whereas the treatment applied had no significant effect on PFHAA. HKs precursors were detected in synthetic matrix and the Temerin water at low concentrations. In the water after the AOP at a dose of 3.0 mg H 2O2 /mg DOC of hydrogen peroxide, HANs and chloropicrin were formed. The applied treatment led to the formation of brominated DBPs.All the results obtained during the research indicate the necessity of optimization the process in the treatment of the examined water matrices and determination of the optimal process taking into account the characteristics of raw water and the efficiency to be achieved. By combining two or more conventional treatments and optimizing the reaction conditions, high NOM removal efficiency can be achieved, as well as removal of the targeted precursor material of the selected DBPs, but the treatment of ozone water at a dose of 1.0 mg O3 /mg DOC was proved to be an optimal process.
Sevilla, Esparza Cindy Jocelyn. "Efficacy of Catalytic Ozonation Advanced Oxidation Processes Compared to Traditional Ozone-Based Advanced Oxidation Processes for Degradation of Recalcitrant Compounds." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2207.
Full textEscalona, Hernández Ivonne Graciela. "Membrane-assisted advanced oxidation processes for wastewater treatment." Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/284445.
Full textBisfenol A (BPA) y tartrazina (TAR) pertenecen al grupo de compuestos que son potencialmente dañinos para la recuperación de aguas residuales. BPA es un perturbador del sistema hormonal o disruptor endocrino, mientras que la TAR es un colorante azo. Variedad de industrias, especialmente la industria papelera y textil producen un gran volumen de aguas residuales que están contaminadas con BPA y colorantes. Por lo tanto, los efluentes que contiene tanto BPA como colorantes, deben ser gestionados de manera eficiente con la finalidad de evitar problemas ambientales vinculados a ellos. Durante la última década, varios métodos para la eliminación de BPA y TAR de aguas residuales han sido probados, resultando ser eficaces y potencialmente aplicables a gran escala. Sin embargo, la mayoría de ellos todavía enfrentan problemas de costes, lo cual exige su desarrollo. La nanofiltración (NF) ofrece una solución adecuada para la eliminación de BPA y colorantes de las soluciones acuosas debido a su capacidad para remover sustancias orgánicas disueltas. Es por ello que en esta tesis, la NF en flujo cruzado usando membranas poliméricas fue utilizada para remover BPA y TAR de soluciones acuosas. Adicionalmente, la degradación de BPA y TAR durante los tratamientos por Fenton, ozonación y enzimático bajo diferentes condiciones de operación, en combinación con su posterior NF fueron ensayados. Resultados indican que tanto el BPA como la TAR pueden ser eficientemente degradados por estos procesos. El uso de un sistema integrado membrana-reactor mostró el potencial y las limitaciones del uso de los procesos de oxidación avanzada en conjunto con membranas de NF para la remoción del BPA y de la TAR. En general elevadas eficiencias de remoción fueron alcanzadas con las diferentes membranas de NF utilizadas.
Bisphenol A (BPA) and tartrazine (TAR) belong to the compounds which are potentially harmful during wastewater reclamation. BPA is a typical Endocrine Disrupting Chemical and TAR is an azo dye. Variety of industry, especially paper and textile industries produces a large volume of wastewater that is polluted with BPA and dyes. Therefore, BPA and dyes-charged effluents need to be efficiently managed in order to avoid environmental problems linked to them. During the last decade, several methods for BPA and TAR removal of wastewater have been found effective and potentially applicable for scaling up. However, most of them still face cost problems, thus demanding further development. It is generally accepted that nanofiltration (NF) offers an adequate solution for the removal of BPA and dyes from the aqueous solutions owing to its capacity to remove dissolved organics. In the present thesis, crossflow NF using thin film composite polymeric membranes were applied to reject BPA and TAR from aqueous solutions. Additionally, the degradation of BPA and TAR during Fenton’s, ozonation and enzymatic processes under different operational conditions, in combination with subsequent NF of low concentration remnant BPA and TAR and compounds derived from oxidation was investigated. Results indicate that BPA and TAR could be degraded efficiently in aqueous phase by Fenton, ozonation and enzymatic processes. The use of a membrane-reactor integrated system for BPA and TAR degradation demonstrated the potential and limitations of using advance oxidation processes, operated in a recycling mode coupled to a NF membrane. In general, high BPA and TAR removal efficiencies for several NF membranes were achieved.
Yalfani, Mohammad Sadegh. "New catalytic advanced oxidation processes for wastewater treatment." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/34768.
Full textRegarding to the improvement of Advanced Oxidation Processes for wastewater treatment, new catalytic Fenton process and catalytic ozonation were designed and studied in the removal of organic pollutants from water. Fenton process was performed using in situ generated hydrogen peroxide, which was produced from formic acid and oxygen over alumina-supported palladium catalyst. Then, the system was fully heterogenized by using bimetallic Pd-Fe catalyst and applied successfully for different categories of organic pollutants. The combination of the above oxidation process with hydrodechlorination led to high efficiency in the degradation of chlorophenols. The performance of different hydrogen substitutes in the Fenton process using in situ generated hydrogen peroxide showed higher efficiency of hydroxylamine for neutral solutions. Concerning the development of new catalytic materials for catalytic ozonation, the degradation of pharmaceutical compounds was performed using dawsonite-derived copper catalysts. The copper incorporated into the structure of dawsonite indicated higher activity in catalytic ozonation with respect to the calcined sample, soluble copper and aluminasupported copper oxide.
Bach, Altai. "Water purification by advanced oxidation processes using nano particles." Online version, 2010. http://dds.crl.edu/CRLdelivery.asp?tid=13238.
Full textRomero, Olarte Rossmary Violette. "Degradation of metoprolol by means of advanced oxidation processes." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/294150.
Full textEn este trabajo se ha estudiado la eficacia de varios Procesos de Oxidación Avanzada (UVC/H2O2, fotocatálisis, Fenton, foto-Fenton, bicarbonato/H2O2 con y sin catalizador) para degradar el fármaco Metoprolol (MET). Además se ha comparado la eficiencia energética de los diferentes procesos y diferentes instalaciones en la eliminación de MET. Los experimentos se realizaron con 50 mg/L iniciales de MET en agua Mili-Q, pH libre y 25ºC. En el caso de la fotólisis, se usaron cuatro instalaciones (solarbox (SB), concentradores parabólicos compuestos (CPC), lámparas black light blue (BLB) y UVC254 nm (UVC)) y el mejor resultado obtenido fue (UVC: 93,5%). Los experimentos UVC se realizaron a diferentes pH y concentraciones de H2O2 con una eliminación de MET de 98%. Los experimentos de fotocatálisis se llevaron a cabo con luz natural y artificial, variando la concentración de TiO2 (0,05, 0,10 y 0,40 g/L). También se realizaron experimentos con 0,4 g/L TiO2 pero variando la concentración inicial del MET (25, 50 y 100 mg/L), el pH, la matriz acuosa y adicionando peróxido de hidrógeno. Los mejores resultados fueron (CPC: 81,5% y SB: 100%). Los experimentos de Fenton se realizaron a pH 3,0 en un reactor de 2 L. Para mejorar el proceso, la adición del Fe (II) se dividió en 5 adiciones realizadas a intervalos constantes de tiempo durante 60 minutos. La mejor degradación de MET fue 87%. Los experimentos de foto-Fenton se realizaron a pH 3,0 y temperaturas de 14ºC y 25ºC en cuatro instalaciones diferentes (BLB, SB, CPC y UVC). Los mejores resultados obtenidos para la eliminación de MET fueron (BLB: 100%; SB: 97,3% y CPC: 98,3%). Los experimentos con bicarbonato/H2O2 se realizaron con 5 mg/L iniciales de MET en agua potable, pH libre y temperatura ambiental en un reactor de 0,5 L. Adicionalmente se utilizó Co (II) y Fe (II) como catalizadores. Eliminación de MET de 100%. Se realizó la identificación de los diferentes intermedios y se han establecido los posibles caminos de degradación del MET. Finalmente se realizó un estudio de un método actinométrico para poder realizar mediciones de radiación en un reactor fotocatalítico en presencia de un catalizador en suspensión.
Philippe, Karine K. "The role of advanced oxidation processes in drinking water treatment." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6782.
Full textLaw, Cheuk Fung Japhet. "Catalytic advanced oxidation processes for degradation of environmental emerging contaminants." HKBU Institutional Repository, 2019. https://repository.hkbu.edu.hk/etd_oa/610.
Full textTummolo, Mauro. "Advanced Oxidation Processes for water remediation by crude oil pollution." Lyon 1, 2009. http://www.theses.fr/2009LYO10005.
Full textLe pétrole, probablement le mélange organique le plus complexe, est un liquide naturel et inflammable constitué de composés organiques ayant des propriétés chimiques différentes: hydrocarbures saturés et insaturés, composés hétéro‐atomiques (N S et O) et une petite quantité de métaux. La pollution de l’eau et du sol causée par le pétrole est un problème mondial. Les hydrocarbures arrivent dans l'environnement par des épanchements accidentels ou des fuites industrielles ou, encore, comme sous‐produits de l’activité commercial et domestique. Quelque soit le type de pollution (primaire ou secondaire, c'est‐à‐dire directe ou occasionnel) les hydrocarbures du pétrole arrivent sur la surface du sol et dans l’eau et peuvent arriver dans les nappes aquifères et entrer dans la chaîne alimentaire. L’irradiation solaire représente un procédé naturel d’atténuation des polluants organiques à la surface des sols pouvant servir par exemple à la décontamination de sites contaminés par le pétrole. Ce procès peut être accéléré avec l’utilisation de catalyseurs (photocatalyse) tel que le bioxyde de titane (TiO2) qui semble être le catalyseur le plus efficace et économique. Depuis quelques années on étudie, aussi, l’application soit des ultrasons (sonolyse) soit le couplage sonolyse‐photocatalyse afin de dégrader les polluants organiques dans l’eau. Toutefois la littérature ne reporte pas des articles scientifiques qui appliquent ce couplage pour la purification de l'eau contaminée par les hydrocarbures dérivés du pétrole. Le but de ce travail, pourtant, a été d’étudier la possibilité d'appliquer des méthodes d’oxydation extrême (AOPs, Advanced Oxidation Processes) pour la purification d'eau polluée par le pétrole. Pour les essais de dégradation on a préparé une suspension eau/pétrole dans un récipient en Pyrex (10 L). Dans le récipient on a introduits 7,0 L d'eau distillé et pétrole en rapport 1/20 (pétrole/eau). La solution a été maintenue en agitation à l’obscurité pour 30 jours pour permettre à l'eau de se saturer d’hydrocarbures. La dégradation du pétrole dissous dans l’eau a été menée par sonolyse à 20 kHz, par photocatalyse et par sonophotocatalyse. La dégradation photocatalytique à été menée en utilisant une lampe HPK 125 W et TiO2 comme catalyseur alors que pour la sonolyse on à utilisé un ultrason de puissance électrique enregistrable entre 7 e 100 W. Les échantillons du pétrole ont été analysés par chromatographie gazeuse couplée à la spectrométrie de masse (GC‐MS), par résonance magnétique nucléaire sur le proton liquide (1H RMN), par spectrométrie de masse à Résonance Cyclotronique Ionique et Transformée de Fourier (FT‐ICR‐MS) et par fluorescence. L’étude en GC‐MS des composés non polaires du pétrole irradiés dans le simulateur solaire, a montré, après l’irradiation, une augmentation de la quantité relative de la fraction C13‐C23 et une réduction de la fraction C7‐C12. L’analyse des mêmes échantillons en FT‐ICR‐MS à montré l'oxygénation des doubles liaisons et une augmentation des produits d’oxydation. Les analyses en GC‐MS des composes non polaires, présents dans la fraction soluble du pétrole naturel, ont montrés une forte présence d'alcanes complexes et une grande quantité d'alcanes linéaires et aromatiques. En général, les trois méthodes de dégradation utilisées (sonolyse, photocatalyse, et sonophotocatalyse) ont produit une augmentation des composée en C5 et une diminution de la fraction C6‐C9. Les analyses en FT‐ICR des composés polaires ont relevé rien de remarquable après la sonolyse, une légère diminution des composes oxygénés après les photocatalyse et une évidente réduction des mêmes composes après la sono‐photocatalyse. Les diagrammes de Kendrick et van Krevelen confirment ces résultats: on observe, en effet, une augmentation des composés avec bas poids moléculaire et une légère augmentation d'atomes d’oxygène. En conclusion on peut affirmer que les ultrasons ont une influence remarquable sur la dégradation photocatalytique des polluants organiques. La sonophotocatalyse, pourtant, grâce à la synergie d’action, augmente l'efficacité du procès de dégradation
Brienza, Monica. "Solar Advanced Oxidation Processes for removing emerging contaminants in wasterwater." Thesis, Perpignan, 2015. http://www.theses.fr/2015PERP0001.
Full textWastewater effluents are the major source of micropollutants in the environment. These recalcitrant compounds that can be escape from wastewater treatment plant (WWTP) are called emerging contaminants. It is necessary to improve the efficiency of wastewater treatment plants. In fact, Water Framework Directive required a “good chemical and biological status” of all water bodies until 2015. The major aim of the dissertation was to contribute to improve the evaluation of solar advanced oxidation processes, and more specifically heterogeneous and homogeneous photocatalysis, for removing emerging contaminants from wastewater effluents. In this objective, the efficiency of AOPS was not only evaluated with the degradation and/or mineralization rates of the micropollutants. This necessary criterion was completed with the identification of the by-products and the associated transformation pathways, but also with toxicity measurements. This last point was explored with standard ecotoxicity tests and also estrogenic activity that represent a specific test relevant to characterize an identified risk associated to the discharge of effluents into the environment.All the experimental results obtained during this dissertation tends to demonstrate that solar advanced oxidation processes has the potential to open new feasible remediation strategies for WWTPs effluent tertiary treatment before wastewater reuse in irrigation for instance. All the tested molecules have systematically been degraded, high number of micro-organic pollutants initially presented in a mixture were removed even at very low concentration, environmental compatibility is systematically improved
Hantoosh, Mohammed, and Mohammed Hantoosh. "Advanced Oxidation Processes of Trace Organics in Water by Solar Photolysis." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/620873.
Full textSanly, Chemical Sciences & Engineering Faculty of Engineering UNSW. "Applications of advanced oxidation processes for the treatment of natural organic matter." Publisher:University of New South Wales. Chemical Sciences & Engineering, 2009. http://handle.unsw.edu.au/1959.4/43624.
Full textZhang, Tianqi, and Tianqi Zhang. "Modeling Photolytic Advanced Oxidation Processes for the Removal of Trace Organic Contaminants." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625878.
Full textBernat, Camí Xavier. "Treatment of biorefractory wastewater through membrane-assisted oxidation processes." Doctoral thesis, Universitat Rovira i Virgili, 2010. http://hdl.handle.net/10803/8583.
Full textWater scarcity is one of the major challenges for assuring a sustainable development. Among other measures, research into efficient wastewater treatment systems to deal with biorefractory wastewaters, which need to be amended before their biological degradation, is required. The Fenton process is an advanced oxidation process that can be used as potential pre-treatment for this purpose. However, the pre-treatment presents two main limitations: the use of iron salts as homogeneous catalyst, which are continuously thrown away in the reactor effluent, and the high consumption of oxidant, which is partially wasted. The present thesis aims at studying the improvement of the Fenton process applied on phenolic wastewater through its coupling with membrane technologies such as nanofiltration, membrane emulsification or membrane reactors. The coupling allows confining the catalyst and increasing the oxidation efficiency, thus enhancing the treatment efficiency in environmental and economic terms.
Gutmann, Emanuel. "Nasschemisch synthetisierte, oxidische Nanomaterialien mit pyroelektrokatalytischen und photokatalytischen Eigenschaften für Anwendungen in der Desinfektionstechnologie." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2013. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-102099.
Full textThis thesis deals with two classes of oxidic nanomaterials that were synthesized by chemical solution routes and characterized with respect to structure and morphology. Sols of TiO2, TiO2/SiO2, Ag/TiO2 and Pd/TiO2 containing the photocatalytically active modification anatase in nanocrystalline form were prepared via a solvothermal sol-gel process. With regard to potential application in disinfection and environmental remediation technology the photocatalytic activity of powders and coatings on textile was investigated by means of E. coli decomposition and organic dye degradation. Further the antimicrobial activity of pyroelectric LiNbO3 and LiTaO3 powder materials under cyclical thermal excitation was demonstrated. In this context the application of the pyroelectric effect in a catalytic or electrochemical process – termed as pyroelectrocatalysis – is of fundamental novelty. Based on the physico-chemical principles of the phenomenon a hypothesis of the mechanism was developed and discussed in analogy with photocatalysis
Paiva, Frederico José de Vaz e. "Redução de carga orgânica recalcitrante de efluente de indústria gráfica por reação de fenton." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2960.
Full textThe Brazilians Mint (CMB) is a national enterprise, with more than 300 years of experience in the production of values and security printings. The production of banknotes, carried out by the Departamento de Cédulas (DECED), consists of three printing stages: off-set, intaglio and typography, followed by finishing and semiautomated packing. The intaglio impression consumes cleaning solution, composed by caustic soda and sulfonated castor oil, for cleaning of the printing cylinder, producing an ink saturated wastewater. This wastewater presents low biodegradability, showing a BOD / COD ratio of approximately 1:4. In terms of treatability, the effluent treatment stations (ETS) has presented a conventional configuration, for biological means, has showed a low efficiency in the organic matter degradation of this effluent. With recalcitrant compounds, its necessary the inclusion of a tertiary stage that allows its degradation by chemical means, allowing discarding it with less harmful characteristics to the environment. In this work, the Fenton reaction was applied in the DECED industrial wastewater due to its capacity of converting the organic matter into carbonic gas and water or, if it is used in pay-treatment, turn them into biodegradable (AGUIAR et al., 2007). Different conditions have been studied to measure the influence of different parameters in the reaction efficiency. The Fenton reaction consists in the hidroxyl radicals (HO) generation, by different means, in sufficient quantities for the organic matter degradation. These radicals are produced from of peroxide hydrogen (H2O2) in reactions with different precursors like ozone (O3), UV light, ultrasound and iron salts (GOGATE and PANDIT, 2004). Here we restricted ourselves to the reactions with iron salts. Among the obtained results, it has been verified the minimun time for reaction in 10 minutes. The ratio between iron ions and hydrogen peroxide is lower than suggests the literature (1:2), against (1:3). Since the ferrous sulphate solution is very unstable, because the ferrous ions turn into ferric ions, straight addition of the salt was used. In industrial scale, the ferrous sulfate solution must be prepared in little quantities so that it has low time of stock, in order to not be degraded. The temperature, in the studied range, is a parameter that has little influence, since the efficiency reduction of the reaction was low. The iron used in the reaction did not demonstrate itself a new source of damages for the environment. In the used conditions, the iron concentration was near to maximum limit allowed by the legislation in the effluent treatment, just needing some adjustments to sort out the problem
Santana, Caroline Martins. "Estudo da degradação de corante têxtil em matrizes aquosas por meio dos processos oxidativos avançados O3-H2O2/UV e foto-Fenton." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-11082010-143735/.
Full textThe textile industry generates large volumes of wastewater with high organic load, strong coloration and toxicity. In this work, the treatment of an aqueous solution containing the dye Solophenyl Yellow Arle 154% was studied by the O3-H2O2/UV and photo-Fenton processes, in order to evaluate the responses color removal after 5 minutes; color removal after 60 minutes; maximum rate of color removal; and TOC removal after 60 minutes. The experiments were carried out in the semi-batch mode with circulation using a photochemical reactor with annular coaxial radiation field, consisting of a cylindrical stainless steel support with an aluminum internal reflector with 12 lamps fixed symmetrically in the internal reflecting surface, and a quartz tube reactor of 0.7 L, positioned vertically along the axis of the reflector. For the O3- H2O2/UV process, Phillips TUV lamps (36 W, 254 nm) were used; the gas stream containing zone was introduced into the reactor through a diffuser. For the photo- Fenton process, Sylvania lamps (12 W each, 300 - 400 nm) and a concentration of Fe (II) of 0.25 mmol/L were used. In both cases, the hydrogen peroxide solution was added in the first 30 minutes of treatment. The samples were analyzed by the measurement of total organic carbon (TOC) and color removal (absorbance measured at 405 nm in a UV-visible spectrophotometer). In both cases the Doehlert experimental design was used, defining the minimum and maximum values of each variable adopted. In the case of O3-H2O2/UV process (PHASE I), the effects of the total electric power of the lamps (144 - 432 W), H2O2 concentration (5 - 30 mmol/L), initial dye concentration (20 - 100 mg/L), ozone concentration (10 - 40 mg/L), and pH (3 - 10) were studied. For the photo-Fenton process, the studied variables were: total electric power of the lamps (160 - 480 W), H2O2 concentration (5 - 30 mmol/L), and initial dye concentration (20 - 100 mg/L). The results of PHASE I indicated that the increase of dye concentration in acidic conditions increases color removal after 5 and 60 minutes, thus suggesting the efficiency of molecular ozone action upon the chromophore group of the dye. The best results showed color removal above 95% after 5 and 60 minutes of treatment. However, for the TOC removal the process was not efficient, with maximum removal after 60 minutes of only 35.6%. In PHASE II less satisfactory results for color removal were obtained in comparison with PHASE I (56.1% after 5 minutes and 78% after 60 minutes of treatment), but with higher TOC removal after 60 minutes, achieving over 45.1%. The highest color removal rates were observed within the first 5 minutes of treatment for all runs. Additional experiments carried out in PHASE III showed that the oxidation by O3 followed by the photo-Fenton process enabled to achieve suitable results for both color (97.2%) and TOC removals (69.5%). The study of the O3 process in the continuous mode and a preliminary economic evaluation suggests a high potential for the use of the integrated O3-photo-Fenton process in textile industries.
劉偉藻 and Wai-cho Ivan Lau. "Removal of refractory chemicals in landfill leachate by UASB and advanced oxidation processes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31240471.
Full textRossouw, Arnoux. "Modified track-etched membranes using photocatalytic semiconductors for advanced oxidation water treatment processes." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80276.
Full textENGLISH ABSTRACT: The purpose of this study was to develop modi ed tract-etched membranes using nanocomposite TiO2 for advanced water treatment processes. Photocatalytic oxidation and reduction reactions take place on TiO2 surfaces under UV light irradiation, therefore sunlight and even normal indoor lighting could be utilised to achieve this effect. In membrane ltration, caking is a major problem, by enhancing the anti-fouling properties of photocatalysts to mineralise organic compounds the membrane life and e ciency can be improved upon. In this study the rst approach in nanocomposite membrane development was to directly modify the surface of polyethylenetherephthalate (PET) track-etched membranes (TMs) with titanium dioxide (TiO2) using inverted cylindrical magnetron sputtering (ICMS) for TiO2 thin lm deposition. The second approach was rst to thermally evaporate silver (Ag) over the entire TM surface, followed by sputtering TiO2 over the silver-coated TM. As a result a noble metal-titania nanocomposite thin lm layer is produced on top of the TM surface with both self-cleaning and superhydrophilic properties. Reactive inverted cylindrical magnetron sputtering is a physical vapour deposition method, where material is separated from a target using high energy ions and then re-assimilated on a substrate to grow thin lms. Argon gas is introduced simultaneously into the deposition chamber along with O2 (the reactive gas) to form TiO2. The photocatalytic activity and other lm properties, such as crystallinity can be in uenced by changing the sputtering power, chamber pressure, target-to-substrate distance, substrate temperature, sputtering gas composition and ow rate. These characteristics make sputtering the perfect tool for the preparation of di erent kinds of TiO2 lms and nanostructures for photocatalysis. In this work, the utilisation of ICMS to prepare photocatalytic TiO2 thin lms deposited on track-etched membranes was studied in detail with emphasis on bandgap reduction and TM surface regeneration. Nanostructured TiO2 photocatalysts were prepared through template directed deposition on track-etched membrane substrates by exploiting the good qualities of ICMS. The TiO2-TM as well as Ag-TiO2-TM thin lms were thoroughly characterised. ICMS prepared TiO2 lms were shown to exhibit good photocatalytic activities. However, the nanocomposite Ag-TiO2 thin lms were identi ed to be a much better choice than TiO2 thin lms on their own. Finally a clear enhancement in the photocatalytic activity was achieved by forming the Ag-TiO2 nanocomposite TMs. This was evident from the band-gap improvement from 3.05 eV of the TiO2 thin lms to the 2.76 eV of the Ag-TiO2 thin lms as well as the superior surface regenerative properties of the Ag-TiO2-TMs.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om verbeterde baan-ge etste membrane (BMe) met behulp van nano-saamgestelde titaandioksied (TiO2) vir gevorderde water behandeling prosesse te ontwikkel. Fotokatalitiese oksidasie- en reduksie reaksies vind plaas op die TiO2 oppervlaktes onder UV-lig bestraling, en dus kan sonlig en selfs gewone binnenshuise beligting gebruik word om die gewenste uitwerking te verkry. In membraan ltrasie is die aanpaksel van onsuiwerhede 'n groot probleem, maar die verbetering van die self-reinigende eienskappe van fotokatalisators deur organiese verbindings te mineraliseer, kan die membraan se leeftyd en doeltre endheid verbeter word. In hierdie studie was die eerste benadering om nano-saamgestelde membraan ontwikkeling direk te verander deur die oppervlak van polyethylenetherephthalate (PET) BMe met 'n dun lagie TiO2 te bedek, met behulp van reaktiewe omgekeerde silindriese magnetron verstuiwing (OSMV).Die tweede benadering was eers om silwer (Ag) termies te verdamp oor die hele BM oppervlak, gevolg deur TiO2 verstuiwing bo-oor die silwer bedekte BM. As gevolg hiervan is 'n edelmetaal-titanium nano-saamgestelde dun lm laag gevorm bo-op die oppervlak van die BM, met beide self-reinigende en verhoogde hidro liese eienskappe. OSMV is 'n siese damp neerslag metode, waar materiaal van 'n teiken, met behulp van ho e-energie-ione, geskei word, en dan weer opgeneem word op 'n substraat om dun lms te vorm. Argon gas word gelyktydig in die neerslag kamer, saam met O2 (die reaktiewe gas), vrygestel om TiO2 te vorm. Die fotokatalitiese aktiwiteit en ander lm eienskappe, soos kristalliniteit, kan be nvloed word deur die verandering van byvoorbeeld die verstuiwingskrag, die druk in die reaksiekamer, teiken-tot-substraat afstand, substraattemperatuur, verstuiwing gassamestelling en vloeitempo. Hierdie eienskappe maak verstuiwing die ideale hulpmiddel vir die voorbereiding van die verskillende soorte TiO2 lms en nanostrukture vir fotokatalisasie. In hierdie tesis word OSMV gebruik ter voorbereiding van fotokatalitiese TiO2 dun lms, wat gedeponeer is op BMe. Hierdie lms word dan in diepte bestudeer, met die klem op bandgaping vermindering en BM oppervlak hergenerasie. Nanogestruktureerde TiO2 fotokataliste is voorberei deur middel van sjabloongerigte neerslag op BM substrate deur die ontginning van die goeie eienskappe van OSMV. Die TiO2-BM dun lms, sowel as Ag-TiO2-BM dun lms, is deeglik gekarakteriseer. OSMV voorbereide TiO2 dun lms toon goeie fotokatalitiese aktiwiteite. Nano-saamgestelde Ag-TiO2 dun lms is egter ge denti seer as 'n veel beter keuse as TiO2 dun lms. Ten slotte is 'n duidelike verbetering in die fotokatalitiese aktiwiteit bereik deur die vorming van die Ag-TiO2 nano-saamgestelde BMe. Dit was duidelik uit die bandgapingverbetering van 3,05 eV van TiO2 dun lms in vergelyking met die 2,76 eV van Ag-TiO2 dun lms. 'n Duidelike verbetering is behaal in die fotokatalitiese aktiwiteit deur die vorming van die Ag-TiO2 nano-saamgestelde TMs.