Cette thèse avait pour but d’étudier les phénomènes physico-chimiques se produisant à l’interface solide minéral/solution en présence d’un oxydant et d’un polluant organique. L’apport du fer comme catalyseur pour l’oxydation du polluant était évalué en sélectionnant deux types d’oxydes mixtes (FeII, FeIII) de fer. Il s’agit d’interactions solide/polluant, oxydant/solide et oxydant/polluant dont les mécanismes réactionnels sont loin d’être compris. Les mécanismes d’oxydoréduction des composés organiques dans la phase aqueuse en contact avec ces minéraux sont fortement influencés par leurs propriétés de surface, leur réactivité vis-à-vis des polluants et la nature des oxydants utilisés. En effet, les phénomènes se produisant à l’interface minéral/solution pourraient avoir un impact significatif d’une part sur l’efficacité de l’oxydation et d’autre part sur la stabilité du système solide. Des caractérisations spectroscopiques couplées à des analyses chimiques ont permis à la fois de décrire les mécanismes d’oxydoréduction à l’interface solide/liquide et de suivre l’efficacité de l’oxydation ainsi que l’évolution structurale du solide. L’influence de l’oxydation sur la nature minéralogique du solide a été abordée. De même, l’effet de la présence des agents chélatants agissant comme pièges des radicaux hydroxyles libres (•OH) sur la performance de l’oxydation a été également étudié. Les résultats présentés dans ce manuscrit contribuent à la bonne compréhension des mécanismes se produisant à l’interface oxyde/solution lors de l’oxydation par Fenton modifiée. Ce travail a permis de mettre en évidence les paramètres optimums durant la dégradation d’un polluant organique comme le pentachlorophénol (PCP) dans le système magnétite/H2O2. De plus, les facteurs influençant le contact oxydant-polluant en comparant deux polluants (RhodamineB et Pentachlorophénol) et deux types d’oxydes mixtes de fer ont été déterminés. Parmi ces facteurs, on peut citer l’hydrophobicité, l’équilibre acido-basique et l’adsorptivité de la molécule, et le contenu en FeII, surface spécifique, minéralogie et propriétés de surface du solide. Il s’agit alors d’une étape significative dans l’évaluation et le suivi de la réaction d’oxydation des polluants organiques dans les sols et les eaux contaminés. L’utilisation de ces données expérimentales a permis une bonne description de la réactivité intrinsèque des oxydes de fer et aussi une optimisation de la réaction d’oxydation. L’utilisation d’un agent complexant fort du fer comme l’EDTA conduit à de meilleurs résultats en phase homogène à pH7. Cependant, l’utilisation de l’oxalate comme les cyclodextrines devient plus intéressante en phase hétérogène. Ces résultats mettent en évidence le rôle important des interactions physico-chimiques à l’interface catalyseur solide/solution dans la détermination de la performance de la réaction d’oxydation du Fenton hétérogène. / Firstly, PCP was chosen as a model pollutant, to investigate the oxidation of PCP on the surface of magnetite used as heterogeneous catalyst. Oxidation experiments were carried out under various experimental conditions at neutral pH and correlated with the adsorption behavior. The surface reactivity of magnetite was evaluated by conducting the kinetic study of both H2O2 decomposition and PCP oxidation experiments. The occurrence of the optimum values of H2O2 and magnetite concentrations for the effective degradation of PCP could be explained by the scavenging reactions with H2O2 or iron oxide surface. All batch experiments indicate that Fenton-like oxidation of PCP was controlled by surface mechanism reaction and the species compete with each other for adsorption on a fixed number of surface active sites. The apparent degradation rate was dominated by the rate of intrinsic chemical reactions on the oxide surface rather than the rate of mass transfer. Raman analysis suggested that the sorbed PCP was removed from magnetite surface at the first stage of oxidation reaction. All X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Mössbauer spectroscopy and chemical analyses showed that the magnetite catalyst exhibited low iron leaching, good structural stability and no loss of performance in second reaction cycle. Secondly, Rhodamine B (RhB) was chosen as a model compound pollutant. Two types of iron (II, III) oxides were used as heterogeneous catalysts and characterized by XRD, Mössbauer spectroscopy, BET surface area, particle size and chemical analyses. The catalytic efficiency of iron (II, III) oxide to promote Fenton-like reaction was examined at neutral pH. The adsorption to the catalyst changed significantly with the pH value and the sorption isotherm was fitted using the Langmuir model for both solids. Both sorption and FTIR results indicated that surface complexation reaction may take place in the system. The variation of oxidation efficiency against H2O2 dosage and amount of exposed surface area per unit volume was evaluated and correlated with the adsorption behavior in the absence of oxidant. There is also an optimum amount of H2O2 value for the degradation of RhB. The phenomena could also be explained by the scavenging effect of hydroxyl radical by H2O2 or by iron oxide surface (like the oxidation of PCP). Sorption and decolourization rate of RhB as well as H2O2 decomposition rate were found to be depended on the surface characteristics of iron oxide. The kinetic oxidation experiments showed that structural FeII content strongly affect the reactivity towards H2O2 decomposition and therefore RhB decolourization. Finally, the effect of chelating agent on the heterogeneous Fenton reaction rate of pentachlorophenol in the presence of magnetite was investigated. Six kinds of chelating agents including oxalate, EDTA, CMCD, tartarate, citrate and succinate were chosen. The PCP oxidation rate in this system was significantly improved by using chelating agents at neutral pH. The kinetic rate constant was increased by 5.7, 4, 3.2, 2.4, 2.5 and 1.7 times with oxalate, EDTA, CMCD, tartarate, citrate and succinate, respectively. The enhancement factor of heterogeneous oxidation rate was found to be not correlated with that of dissolved iron dissolution amount. In homogeneous Fenton system (dissolved Fe2+ or Fe3+), EDTA-driven reaction showed the highest oxidation rate, while oxalate seems to be more efficiency in heterogeneous Fenton system (Fe3O4). This observation could be explained by the inactivation of iron surface sites which become unavailable for the interactions with H2O2 to initiate Fenton-like reactions. These results demonstrated that the chelating agent-promoted dissolution of magnetite did not play the key role in determining the efficiency of heterogeneous Fenton oxidation.

Thesis (M.A.)--Cornell / Copy of typescript. "Program of unveiling of the statue of Governor Reuben E. Fenton ..." inserted between leaf 199 and 200. Includes bibliographical references (leaf 201-218). Also issued in print and microfiche.

Thesis (Ph. D.)--University of Pennsylvania, 1937. / "Bibliography of works cited": p. [6-8].

Made available in DSpace on 2014-06-12T18:06:33Z (GMT). No. of bitstreams: 2 arquivo7835_1.pdf: 2328800 bytes, checksum: bb8d807908d8dccb56d923ffe5cc0978 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / O crescimento urbano e a industrialização vêm provocando o aumento da geração de resíduos sólidos contribuindo para a poluição do ar, da água e do solo. A decomposição desses resíduos gera um líquido denominado lixiviado, cuja composição é variada e complexa. A presença de diversos poluentes no lixiviado impõe a necessidade de um tratamento adequado antes de seu lançamento no corpo receptor. Uma grande variedade de processos físicos, químicos e biológicos é empregada no tratamento desses lixiviados. O lixiviado de aterros sanitários é geralmente tratado por processos biológicos para remoção da carga orgânica presente no efluente. Algumas vezes se faz uso de tratamento por combinação dos processos biológico e avançado. Nos últimos 20 anos, os processos oxidativos avançados (POA) têm merecido destaque devido a sua alta eficiência na degradação de inúmeros compostos orgânicos e custo operacional baixo. Através de um estudo de um planejamento fatorial em sistema de batelada avaliou-se as variáveis ( pH, peróxido de hidrogênio e tempo) em 2 níveis, mais um ponto central em triplicata em ordem aleatória, com o objetivo de se obter uma estimativa do erro experimental puro. A resposta estudada foi a quantidade de matéria orgânica degradada em mg por Litro de grama de lixiviado. Para a otimização do processo, foi realizado um planejamento experimental, onde se buscou como respostas a maximização do percentual de redução da DQO e do teor de carbono orgânico total (TOC). Esta redução variou de 21,3 a 77,6% e 38,2 a 69,2%, respectivamente, para a DQO e para o TOC

Esta dissertação teve como objetivo estudar o acoplamento das micro-ondas ao processo Fenton para o tratamento de uma solução de um corante azóico, tartrazina, 300 mg L-1. Para isso, foi realizado um planejamento fatorial 24 para a determinação dos efeitos dos fatores quantitativos: pH, concentração (razão) de Fe2+/H2O2 e vazão; e do uso das micro-ondas como fator qualitativo, sobre o tratamento. A variável-resposta utilizada foi a porcentagem de descoramento obtida pela área sob o espectro de absorção na região do visível (400 a 700 nm). Os resultados indicaram que o único fator estatisticamente significativo foi o pH. A partir dessa informação, outras avaliações foram realizadas a fim de se reforçar o resultado obtido. Realizaram-se análises de mineralização, ecotoxicidade e cromatografia liquida de alta eficiência, nas melhores condições de tratamento a fim de se comparar os processos Fenton e Fenton acoplado às micro-ondas: [Fe2+] = 1,2 mmol L-1, [H2O2] = 12 mmol L-1, pH 6 e tempo de reação de 25 min. Não foram observadas diferenças significativas de mineralização entre os processos Fenton e Fenton acoplado às micro-ondas, assim como na cromatografia liquida de alta eficiência e na ecotoxicidade. Em condições intermediárias utilizadas no planejamento experimental [Fe2+] = 1,0 mmol L-1, [H2O2] = 10 mmol L-1 e pH 7, variou-se a potência do forno de micro-ondas de 244,2 a 628,0 W e o tempo de residência de 7 a 90 s. Também não houve diferença significativa, tanto no desempenho de descoramento quanto na mineralização. Usando-se uma lâmpada de descarga sem eletrodo por 25 min após a reação de Fenton, mais uma vez não houve diferença significativa entre os processos Fenton e foto-Fenton. Conclui-se, portanto, que dentro da faixa estudada as micro-ondas não interferiram no processo. / This thesis aimed at studying the coupling of microwaves to the Fenton process for the treatment of an azo dye solution, tartrazine, 300 mg L-1. For that, a 24 factorial design was performed to determine the effects of the quantitative factors: pH, Fe2+/ H2O2 concentration (ratio) and flow rate; and the use of microwaves as a quali-tative factor on the treatment. The response-variable was the percentage of color removal obtained by the area under the visible absorption spectra (400 to 700 nm). The results indicated pH as the sole statistically significant factor. Further investiga-tions were performed in order to corroborate the previous result. Mineralization, eco-toxicity, and high performance liquid chromatography analyses were performed with the best treatment conditions in order to compare the Fenton process with the one coupled to microwaves: [Fe2+] = 1.2 mmol L-1, [H2O2] = 12 mmol L-1, pH 6, and reac-tion time of 25 min . No significant differences were observed in mineralization by both processes, as well as in high performance liquid chromatography and ecotoxici-ty analyses. With other conditions also used in the factorial design, [Fe2+] = 1.0 mmol L-1, [H2O2] = 10 mmol L-1, and pH 7, the microwave oven power (244.2 to 628.0 W) and residence time (7 to 90 s). No significant differences, both in color removal and in mineralization were noriced. By using a discharge electrodeless lamp for 25 min after the Fenton reaction, once again no significant difference between Fenton and photo-Fenton processes were noticed. Therefore, it can be concluded that, within the studied range, the microwaves did not interfere in the process.

Advanced oxidation processes (AOPs) have been used to treat drinking water and wastewater but their application to greywater is limited to photocatalysis. Therefore, three homogeneous AOPs were investigated in this project: Fenton, photo-Fenton, and UVC/H2O2 processes. Alum and ferrous sulphate coagulation were also compared and their supernatants were treated by UVC/H2O2. The process comparisons were based on the removal of chemical oxygen demand (COD), treatment type (physical separation versus chemical oxidation), sludge formation, complexity in operation, required pH, visual aesthetic of effluent and energy requirement. Treating greywaters collected from the researcher's home or laboratory, alum coagulation achieved 73% COD removal and was more effective than ferrous sulphate coagulation (49%) and the Fenton process (45%). The photo-Fenton process removed 83% COD, compared with 87% by overnight settlement and subsequent UVC/H2O2 treatment. Using ferrous sulphate and alum, sequential coagulation and UVC/H2O2 treatment removed 91% and 98% COD, respectively. Overnight settlement generated little sludge and the subsequent UVC/H2O2 treatment removed most organic contaminants by oxidation. All other processes produced a large quantity of chemical sludge from coagulation which requires appropriate disposal. Also, the residual iron in some treated water was not aesthetically desirable. The Fenton and photo-Fenton processes were complex and involved the optimisation of multiple parameters. Their requirement for different procedures according to the greywater type presents a major challenge to process design and operation. Due to the non-selectivity of the hydroxyl radicals (●OH), the UVC/H2O2 process was capable of treating all greywaters collected by the researcher, and its operation was moderate in complexity. The COD removal was modelled as a pseudo first-order reaction in terms of H2O2 dosage: The rate constant (k´) increased linearly up to 10 mM H2O2, above which the excess H2O2 scavenged the ●OH and reduced the rate. The overall kinetics of COD removal followed a second-order equation of r = 0.0637 [COD][H2O2]. In contrast to the literature, operation of UVC/H2O2 in acidic conditions was not required and the enhanced COD removal at the initial pH of 10 was attributed to the dissociation of H2O2 to O2H-. Maintaining the pH at 10 or higher resulted in poorer COD removal due to the increased decomposition rate of H2O2 to O2 and H2O. The performance of the UVC/H2O2 treatment was unaffected for initial pH 3 - 10 with the initial total carbonate concentration (cT) of 3 mM. For initial cT ≥ 10 mM, operating between pH 3 and 5 was essential. After 3 hours of the UVC/H2O2 treatment, the effluent met the requirement of Class B reclaimed water specified by the Environment Protection Authority of Victoria, and less than 1 org/100 mL of Escherichia coli survived. A subsequent treatment such as filtration may be required to meet more requirements for biochemical oxygen demand (BOD5), turbidity and total suspended solids. Since the biodegradability (as BOD5:COD) of the greywater was increased from 0.22 to 0.41 with 2 hours of UVC/H2O2 treatment, its integration with a subsequent biological treatment may be viable to reduce the costs and energy consumption associated with the UVC/H2O2 process.

Esta dissertação teve como objetivo estudar o acoplamento das micro-ondas ao processo Fenton para o tratamento de uma solução de um corante azóico, tartrazina, 300 mg L-1. Para isso, foi realizado um planejamento fatorial 24 para a determinação dos efeitos dos fatores quantitativos: pH, concentração (razão) de Fe2+/H2O2 e vazão; e do uso das micro-ondas como fator qualitativo, sobre o tratamento. A variável-resposta utilizada foi a porcentagem de descoramento obtida pela área sob o espectro de absorção na região do visível (400 a 700 nm). Os resultados indicaram que o único fator estatisticamente significativo foi o pH. A partir dessa informação, outras avaliações foram realizadas a fim de se reforçar o resultado obtido. Realizaram-se análises de mineralização, ecotoxicidade e cromatografia liquida de alta eficiência, nas melhores condições de tratamento a fim de se comparar os processos Fenton e Fenton acoplado às micro-ondas: [Fe2+] = 1,2 mmol L-1, [H2O2] = 12 mmol L-1, pH 6 e tempo de reação de 25 min. Não foram observadas diferenças significativas de mineralização entre os processos Fenton e Fenton acoplado às micro-ondas, assim como na cromatografia liquida de alta eficiência e na ecotoxicidade. Em condições intermediárias utilizadas no planejamento experimental [Fe2+] = 1,0 mmol L-1, [H2O2] = 10 mmol L-1 e pH 7, variou-se a potência do forno de micro-ondas de 244,2 a 628,0 W e o tempo de residência de 7 a 90 s. Também não houve diferença significativa, tanto no desempenho de descoramento quanto na mineralização. Usando-se uma lâmpada de descarga sem eletrodo por 25 min após a reação de Fenton, mais uma vez não houve diferença significativa entre os processos Fenton e foto-Fenton. Conclui-se, portanto, que dentro da faixa estudada as micro-ondas não interferiram no processo. / This thesis aimed at studying the coupling of microwaves to the Fenton process for the treatment of an azo dye solution, tartrazine, 300 mg L-1. For that, a 24 factorial design was performed to determine the effects of the quantitative factors: pH, Fe2+/ H2O2 concentration (ratio) and flow rate; and the use of microwaves as a quali-tative factor on the treatment. The response-variable was the percentage of color removal obtained by the area under the visible absorption spectra (400 to 700 nm). The results indicated pH as the sole statistically significant factor. Further investiga-tions were performed in order to corroborate the previous result. Mineralization, eco-toxicity, and high performance liquid chromatography analyses were performed with the best treatment conditions in order to compare the Fenton process with the one coupled to microwaves: [Fe2+] = 1.2 mmol L-1, [H2O2] = 12 mmol L-1, pH 6, and reac-tion time of 25 min . No significant differences were observed in mineralization by both processes, as well as in high performance liquid chromatography and ecotoxici-ty analyses. With other conditions also used in the factorial design, [Fe2+] = 1.0 mmol L-1, [H2O2] = 10 mmol L-1, and pH 7, the microwave oven power (244.2 to 628.0 W) and residence time (7 to 90 s). No significant differences, both in color removal and in mineralization were noriced. By using a discharge electrodeless lamp for 25 min after the Fenton reaction, once again no significant difference between Fenton and photo-Fenton processes were noticed. Therefore, it can be concluded that, within the studied range, the microwaves did not interfere in the process.

Les procédés dits d'oxydation avancés (POA) permettent la dégradation totale (minéralisation) en milieu aqueux des polluants organiques persistants et/ou toxiques pour l'homme et pour l'environnement. Cette étude porte sur l'application de deux POA principaux : électro-Fenton et photo-Fenton, au traitement des eaux polluées par des colorants de textile. La particularité de ces procédés tient à la génération dans le milieu d'entités oxydantes très réactives, les radicaux hydroxyles (●OH) qui sont capables d'oxyder n'importe quelle polluant organique ou organométallique jusqu'au stade ultime d'oxydation, c'est-à-dire la minéralisation (transformation en CO₂ et H₂O). Dans le cas des colorants étudiés (BB41, BR46 et BY28), il a été montré que le taux de minéralisation par le procédé électro-Fenton dépend des paramètres expérimentaux tels que la concentration du catalyseur, l'intensité du courant appliqué, le pH du milieu, etc.. Cette étude a montré que l'électrolyse du colorant suit une cinétique de pseudo premier ordre. Dans les conditions expérimentales optimales (I = 225 mA et [Fe³⁺]₀ = 0,1 mM), les taux de minéralisation obtenus pour des solutions aqueuses des trois colorants étudiés étaient de 93, 82 et 73% pour le BB41, BR46 et BY28 respectivement après 6 h de traitement. Le taux de minéralisation par le procédé photo-Fenton (UV/Fe³⁺/H₂O₂) est fonction des doses des réactifs utilisés et des rapports R = [H₂O₂]/[Fe³⁺] et R' = [Fe³⁺]/[substrat]. Ainsi, les taux de minéralisation obtenus sont de l'ordre de 93% pour le BB41, 85% pour le BR46 et de 95% pour le BY28 pour une durée de traitement de 5 heures avec des rapports R = 10 et R' = 40. L'étude de la dégradation du colorant BB41 sur une unité pilote utilisant le rayonnement solaire a montré que le procédé hélio-photo-Fenton est très efficace. Ce procédé s'inscrit dans une perspective de développement durable et son fonctionnement est basé sur une énergie renouvelable. Une comparaison des performances de minéralisation d'un mélange de colorants par les deux procédés étudiés par l'estimation de l'énergie électrique consommée a montré que les procédés photo-Fenton et électro-Fenton permettent d'atteindre des taux de minéralisation très importants et que le procédé électro-Fenton semble être favorisé avec non utilisation de réactifs chimiques et une faible consommation d'énergie électrique / Advanced oxidation processes (AOPs) permit the total degradation (mineralization) in aqueous solutions of hazardous organic molecules for human being and for the environment. This study concerns the application of two main AOPs: electro-Fenton, and photo-Fenton, to treatment of wastewater containing toxic and/or persistent organic pollutants such as textile dyes. The characteristic of these processes is due to the generation of very reactive and highly oxidizing species, hydroxyl radicals (●OH) which are able to oxidize any organic pollutant until the ultimate oxidation stage, i.e. mineralization (transformation into CO₂ and H₂O).In the study the aqueous solutions of dyes BB41, BR46 and BY28 have been treated by two selected AOPs. It has been shown that the mineralization rate by electro-Fenton process depends on operating parameters such as catalysis concentration, applied current intensity, pH, etc. It was also observed that e dyes degradation obeys to a pseudo first-order reaction. Under the optimal operating conditions ([Fe³⁺] = 0.1mM, I = 225 mA, pH = 3), electro-Fenton process can lead to an almost mineralization of dyes solutions: 93, 82 and 73% of TOC abatement are obtained for BB41, BR46 and BY28 respectively.The rate of mineralization by the photo-Fenton (UV/Fe³⁺/H₂O₂) is a function of used reagents doses, the ratio R = [H2O2]/[Fe³⁺] and R' = [Fe³⁺]/[substrate]. Thus, mineralization rates obtained are around 93% for the BB41, 85% for BR46 and 95% for BY28 for a treatment time of 5 h with a ratios R = 10 and R' = 40. The study of the degradation of the dye BB41 on a pilot plant using solar radiation showed that the process Helio-photo-Fenton is very effective. This process is part of a sustainable development perspective and its operation is based on renewable energy.A comparison of the mineralization performances of different studied processes in terms of mineralization degree and energy efficiency showed that photo-Fenton and electro-Fenton processes permit to reach high mineralization rate and that the electro-Fenton process can be considered the more efficient technique with no use of chemicals and low energy consumption

É consenso entre os cientistas que as Estações de Tratamento de Esgoto são as principais formas de entrada de fármacos no ambiente aquático. Isso acontece porque os processos biológicos convencionais utilizados para o tratamento do esgoto sanitário não são eficientes quanto à remoção de muitos desses compostos sintéticos. Neste contexto, o pós-tratamento utilizando um Processo Oxidativo Avançado (POA) pode degradar os compostos pouco biodegradáveis e produzir água para reúso seguro. Portanto, esta Tese estuda o acoplamento entre um processo biológico anaeróbio-aeróbio e compara dois POA, foto-Fenton e Fenton heterogêneo, como alternativas de pós-tratamento. Os experimentos foram feitos utilizando-se esgoto sanitário real como matriz. Sendo assim, na primeira etapa deste trabalho, um método SPE-HPLC-MS/MS foi desenvolvido e validado para a quantificação dos fármacos Ranitidina, Diclofenaco e Sinvastatina naquela matriz complexa. Na segunda etapa, a degradação dos fármacos por processos biológicos foi estudada em reatores operados em batelada e de escoamento contínuo. Desenvolveu-se uma metodologia para a identificação dos produtos de biodegradação e encontrou-se que tais metabólitos são recalcitrantes e possuem potencial poluidor. Observou-se que os fármacos e seus metabólitos causam efeito tóxico crônico sobre a biomassa, pois a produção de metano foi prejudicada quando comparada à da biomassa que não foi exposta a esses compostos. Na terceira etapa, os POA foram estudados em batelada para se determinar as melhores condições de operação que seriam testadas nas etapas seguintes. Encontrou-se, para o processo foto-Fenton, que os fármacos foram completamente degradados quando se utilizavam duas lâmpadas (16 W de potência elétrica total), ferro (III) e peróxido de hidrogênio nas concentrações de 3,0 e 40 mg L−1, respectivamente, e tempo de detenção hidráulica de 10 min. Zeólita natural foi utilizada como suporte na síntese de um catalisador para Fenton heterogêneo. O catalisador foi estável em condições críticas de reação, porém não pôde degradar os compostos cujas dimensões moleculares eram maiores do que os seus poros. Os processos foram acoplados e operados em modo contínuo durante dez dias, período no qual permaneceram estáveis. Os custos foram estimados e verificou-se que, embora o processo Fenton heterogêneo necessite de 1/3 do capital comparado ao foto-Fenton, o processo heterogêneo não é interessante porque o custo operacional é 4 vezes maior e o processo é limitado para a degradação de moléculas pequenas. Já o processo foto-Fenton degradou todos os fármacos e metabólitos com remoção de carbono orgânico dissolvido e produzindo água potencialmente segura para seu reúso ao custo operacional de US$ 0,27 m−3. Portanto, o processo foto-Fenton foi a melhor alternativa de pós-tratamento avaliada nesta Tese. O processo Fenton heterogêneo seria atrativo apenas para a degradação de moléculas pequenas. / Scientists generally agree that Sewage Treatment Plants are the main inputs of pharmaceuticals into the aquatic environment. That happens because the conventional biological processes used for treating sewage are not efficient in removing many of those synthetic compounds. In this context, Advanced Oxidation Processes (AOP), used as post-treatments, can degrade the poorly biodegradable compounds and produce water for safe reuse. Therefore, this Thesis studies the coupling between an anaerobic-aerobic biological process and compares two AOP, photo-Fenton and heterogeneous Fenton, as post-treatment alternatives. The experiments were performed using real sewage as a matrix. Thus, in the first step of this work, an SPE-HPLC-MS/MS method was developed and validated for the quantification of the pharmaceuticals Ranitidine, Diclofenac, and Simvastatin in that complex matrix. In the second step, the pharmaceuticals degradation by biological processes was studied in batch and continuous flow reactors. A methodology was developed for identifying the biodegradation products and these metabolites were found to be recalcitrant and to have polluting potential. It was observed that the pharmaceuticals and their metabolites caused a chronic toxic effect on biomass, as methane production was impaired when compared to the biomass not exposed to these compounds. In the third step, the AOP were studied in batch mode to determine the best operating conditions that would be tested in the following steps. In the photo-Fenton process, the pharmaceuticals were completely degraded when two lamps (16 W total electric power), iron (III), and hydrogen peroxide were used in the concentrations of 3.0 and 40 mg L−1, respectively, with hydraulic detention time of 10 min. Natural zeolite was used as a support for the synthesized catalyst for heterogeneous Fenton. The catalyst was stable under critical reaction conditions, but it was not able to degrade compounds whose molecular dimensions were larger than its pores. The processes were coupled and operated in continuous mode for ten days, during which they remained stable. Considering the involved estimated costs, although the heterogeneous Fenton process requires 1/3 of the capital costs when compared to the photo-Fenton process, the heterogeneous one is not interesting because its operating cost is 4 times higher and it is limited to the degradation of small molecules. On the other hand, the photo-Fenton process degraded all pharmaceuticals and their metabolites, removed dissolved organic carbon, and produced water potentially safe for reuse at the operational cost of US$ 0.27 m−3. Therefore, the photo-Fenton process was the best post-treatment alternative assessed in this Thesis. The heterogeneous Fenton process would be suited only for the degradation of small molecules.

É consenso entre os cientistas que as Estações de Tratamento de Esgoto são as principais formas de entrada de fármacos no ambiente aquático. Isso acontece porque os processos biológicos convencionais utilizados para o tratamento do esgoto sanitário não são eficientes quanto à remoção de muitos desses compostos sintéticos. Neste contexto, o pós-tratamento utilizando um Processo Oxidativo Avançado (POA) pode degradar os compostos pouco biodegradáveis e produzir água para reúso seguro. Portanto, esta Tese estuda o acoplamento entre um processo biológico anaeróbio-aeróbio e compara dois POA, foto-Fenton e Fenton heterogêneo, como alternativas de pós-tratamento. Os experimentos foram feitos utilizando-se esgoto sanitário real como matriz. Sendo assim, na primeira etapa deste trabalho, um método SPE-HPLC-MS/MS foi desenvolvido e validado para a quantificação dos fármacos Ranitidina, Diclofenaco e Sinvastatina naquela matriz complexa. Na segunda etapa, a degradação dos fármacos por processos biológicos foi estudada em reatores operados em batelada e de escoamento contínuo. Desenvolveu-se uma metodologia para a identificação dos produtos de biodegradação e encontrou-se que tais metabólitos são recalcitrantes e possuem potencial poluidor. Observou-se que os fármacos e seus metabólitos causam efeito tóxico crônico sobre a biomassa, pois a produção de metano foi prejudicada quando comparada à da biomassa que não foi exposta a esses compostos. Na terceira etapa, os POA foram estudados em batelada para se determinar as melhores condições de operação que seriam testadas nas etapas seguintes. Encontrou-se, para o processo foto-Fenton, que os fármacos foram completamente degradados quando se utilizavam duas lâmpadas (16 W de potência elétrica total), ferro (III) e peróxido de hidrogênio nas concentrações de 3,0 e 40 mg L−1, respectivamente, e tempo de detenção hidráulica de 10 min. Zeólita natural foi utilizada como suporte na síntese de um catalisador para Fenton heterogêneo. O catalisador foi estável em condições críticas de reação, porém não pôde degradar os compostos cujas dimensões moleculares eram maiores do que os seus poros. Os processos foram acoplados e operados em modo contínuo durante dez dias, período no qual permaneceram estáveis. Os custos foram estimados e verificou-se que, embora o processo Fenton heterogêneo necessite de 1/3 do capital comparado ao foto-Fenton, o processo heterogêneo não é interessante porque o custo operacional é 4 vezes maior e o processo é limitado para a degradação de moléculas pequenas. Já o processo foto-Fenton degradou todos os fármacos e metabólitos com remoção de carbono orgânico dissolvido e produzindo água potencialmente segura para seu reúso ao custo operacional de US$ 0,27 m−3. Portanto, o processo foto-Fenton foi a melhor alternativa de pós-tratamento avaliada nesta Tese. O processo Fenton heterogêneo seria atrativo apenas para a degradação de moléculas pequenas. / Scientists generally agree that Sewage Treatment Plants are the main inputs of pharmaceuticals into the aquatic environment. That happens because the conventional biological processes used for treating sewage are not efficient in removing many of those synthetic compounds. In this context, Advanced Oxidation Processes (AOP), used as post-treatments, can degrade the poorly biodegradable compounds and produce water for safe reuse. Therefore, this Thesis studies the coupling between an anaerobic-aerobic biological process and compares two AOP, photo-Fenton and heterogeneous Fenton, as post-treatment alternatives. The experiments were performed using real sewage as a matrix. Thus, in the first step of this work, an SPE-HPLC-MS/MS method was developed and validated for the quantification of the pharmaceuticals Ranitidine, Diclofenac, and Simvastatin in that complex matrix. In the second step, the pharmaceuticals degradation by biological processes was studied in batch and continuous flow reactors. A methodology was developed for identifying the biodegradation products and these metabolites were found to be recalcitrant and to have polluting potential. It was observed that the pharmaceuticals and their metabolites caused a chronic toxic effect on biomass, as methane production was impaired when compared to the biomass not exposed to these compounds. In the third step, the AOP were studied in batch mode to determine the best operating conditions that would be tested in the following steps. In the photo-Fenton process, the pharmaceuticals were completely degraded when two lamps (16 W total electric power), iron (III), and hydrogen peroxide were used in the concentrations of 3.0 and 40 mg L−1, respectively, with hydraulic detention time of 10 min. Natural zeolite was used as a support for the synthesized catalyst for heterogeneous Fenton. The catalyst was stable under critical reaction conditions, but it was not able to degrade compounds whose molecular dimensions were larger than its pores. The processes were coupled and operated in continuous mode for ten days, during which they remained stable. Considering the involved estimated costs, although the heterogeneous Fenton process requires 1/3 of the capital costs when compared to the photo-Fenton process, the heterogeneous one is not interesting because its operating cost is 4 times higher and it is limited to the degradation of small molecules. On the other hand, the photo-Fenton process degraded all pharmaceuticals and their metabolites, removed dissolved organic carbon, and produced water potentially safe for reuse at the operational cost of US$ 0.27 m−3. Therefore, the photo-Fenton process was the best post-treatment alternative assessed in this Thesis. The heterogeneous Fenton process would be suited only for the degradation of small molecules.