The purpose of this study was to characterize the leachate from a landfill in Pennsylvania that had been pretreated by activated sludge and propose the most efficient treatment for this effluent. These samples had been pretreated in a sequencing batch reactor that also was operated to remove nitrogen by nitrification/denitrification. The SBR samples were found to have low BOD, high COD, high TOC and a very low BOD/COD ratio. These SBR decant samples have poor UV transmittance and hence quench UV light. Five treatment methods were evaluated, coagulation, ultrafiltration, combined coagulation/ultrafiltration, combined ultrafiltration/oxidation and combined filtration/fentons. These processes were tested for their ability to remove BOD and TOC and also to evaluate the improvement in UV transmittance. It was found that coagulation; Ultrafiltration and Ultrafiltration combined with coagulation do not work in improving the transmittance properties though there is a significant BOD and TOC removal with these processes. Ultrafiltration combined with oxidation was found to work the best in terms of TOC removal. In this study, four oxidants, KMnO?, H?O?, NaOCl and Fenton's reagent were used. It was observed that Fenton's reagent was capable of removing 90% TOC at a dose of 1g/L each of iron salt and hydrogen peroxide at a pH of 4.5. Since Fentons reagent was found to be the most effective method, hence, efforts were made to optimize the oxidation process with Fenton's. The two parameters which were studied were the initial pH and the chemical dosage. The initial pH was varied from a value of 2.5 to 6.5. The range of iron salt and peroxide dose used was from 0.05 to 0.1 g/L. Additional studies were conducted using samples filtered through a 0.45 um filter and oxidized with Fenton's reagent. The Fenton's process for oxidation of filtrates from the 0.45?m filter was also optimized with respect to pH and chemical dosage to determine the most economical operating conditions. The maximum transmittance of 57% was obtained for an iron dose of 0.075 g/L and a peroxide dose of 0.075 g/L at a pH of 4.5. This is in comparison to the transmittance of unoxidized 1K ultrafiltrate which was found to be 21.5%. There was a significant difference in the performance of 1K and 0.45um filtrates in terms of TOC removal and percentage transmittance. The oxidation process for improving the UV transmittance of leachate can therefore be economically optimized depending upon the desired efficiency by varying the operational parameters. / Master of Science

Landfill leachate is considered as a complex wastewater with various organic and inorganic species which must meet strict discharge standards before its release. Due to such high concentration of diverse pollutants, leachate is low in biodegradation; therefore, a proper usage of physicochemical treatments is required. In this study, membrane distillation (MD) has been used along with Fenton treatment process for pre-coagulation to achieve an effective removal of contaminants. MD is a technology derived with vapor pressure difference across the hydrophobic membrane which traps the feed-wastewater vapor at the entrance of the hydrophobic side before permeation. In order to modify and assist in membrane technology's common drawback, which is dealing with foulants, Fenton oxidation is coupled in the leachate treatment process. Fenton is reserved to be the most effective for leachate treatment and is widely used due to its simple operation and low costs. Fenton oxidation was able to lessen the chemical oxygen demand (COD) concentration of leachate up to 55% while increasing the conductivity and reducing the concentration of NH4-N. The membrane flux and volume had a significant increase with a use of lower COD leachate after Fenton treatment coupled with MD. / Master of Science / Landfilling has been recognized as a principal disposal process of municipal solid wastes globally over the past decades, and this disposal method has been one of the leading concerns for a continuous production of landfill leachate. Leachate is considered as a complex wastewater with a variety of organic and inorganic species which must meet strict discharge standards before its release. Due to such high concentration of diverse pollutants, leachate is low in biodegradation; therefore, a proper usage of physicochemical treatments is required. In this study, membrane distillation (MD) has been used along with Fenton treatment process for pre-coagulation to achieve an effective removal of contaminants. MD is a technology derived with vapor pressure difference across the hydrophobic membrane which traps the feed-wastewater vapor at the entrance of the hydrophobic side before permeation. MD has several advantages which include reduced operating temperature compared to conventional distillation processes, fewer requirements of membrane cleaning, and lower operating hydraulic pressure than other conventional pressure-driven membrane processes such as reverse osmosis (RO). This technology has a common drawback along with other membrane-required technologies which is dealing with foulants. For a reduction in membrane fouling, Fenton oxidation is coupled in the leachate treatment process. Fenton is reserved to be the most effective for leachate treatment and is widely used due to its simple operation and low costs.

AN ABSTRACT OF THE DISSERTATION OFElizabeth W. Salako, for the Doctor of Philosophy degree in Chemistry, presented on March 27, 2024, at Southern Illinois University Carbondale. TITLE: SYNTHESIS OF NOVEL PERFLUORINATED ION EXCHANGE MEMBRANES AGAINST HYDROGEN PEROXIDE DEGRADATION IN ELECTROCHEMICAL ENERGY STORAGE DEVICES MAJOR PROFESSOR: Dr. Yong GaoThe continuous burning of fossil fuels to meet the energy needs of the ever-growing population has extensive and enduring effects on the environment, human health, and the economy. Adopting cleaner and more sustainable energy sources is crucial to reducing the impact and tackling the difficulties posed by climate change. Renewable energy, which is derived from sources that are naturally replenished, presents a compelling solution to address these pressing challenges. Due to the inherent intermittency of renewable energy available, which relies on weather conditions and daylight hours, incorporating energy storage technology into the power grid can effectively handle unforeseeable power demands.An ion exchange membrane (IEM) is an important part of electrochemical energy storage and conversion devices like fuel cells, flow batteries, and electrolyzers. Without it, these devices would not work properly. The IEM has significantly enhanced these devices by enabling higher operating temperatures and improving their durability and efficiency. The proton exchange membrane (PEM) has been greatly studied, with Nafion® (a product of DuPont) as the state-of-the-art membrane. Even though Nafion®, which belongs to the perfluorosulfonic acid (PFSA) group, has been commercialized, it suffers from low working temperatures, high cost, low tolerance to fuel impurities, and most importantly, degradation of the membrane over a short period of time. The membrane undergoes three main types of degradation: mechanical, thermal, and chemical degradation. Although the mechanical and thermal degradation of the membranes can be managed, the chemical degradation is a more intricate and challenging issue to address. The degradation of Nafion® occurs through the process of radical-induced disintegration of the polymer structure. This selectively targets the weakest points in the polymer structure, thereby fragmenting the polymer and leading to a loss of ionic conductivity. These vulnerable sites include carboxylic acid groups, C-S linkages, tertiary carbons, and fluoro-ether groups. Studies have shown the fluoro-ether groups to be more susceptible to hydroxyl radical attacks. In our aim to reduce membrane degradation, we designed and synthesized novel fluoro-monomers void of the fluoro-ether groups. We used the emulsion polymerization process in a high-pressure reactor to polymerize our synthesized monomers with a commercially available monomer to make different ionomers with -SO3H and -PO3H2 ion exchange groups. We measured the molecular weight of the polymers through the viscometry method. The mechanical properties of the polymers were not as great, and it became difficult to cast them into a thin film. Polytetrafluoroethylene (PTFE) films were used as a support for the polymers to make them stronger and to also measure their ion conductivities in comparison with NafionTM 115. Fenton’s test was employed to measure the susceptibility of the polymers to hydroxyl radical attack. Our polymers were not as good at conducting ions as NafionTM 115, but they were better at protecting against hydroxyl radical attacks, both at room temperature and higher temperatures. The results showed an inverse relationship between the number of fluoroalkyl ether groups present in the polymers and their resistance to hydroxyl radical attacks.

Por meio das mudanças de paradigmas relacionados à gestão ambiental e elevação dos custos de lançamento de efluente, captação e tratamento de água, as indústrias passam por processos de inovação que resultam em melhor utilização dos recursos e maior diminuição dos custos. Além disso, as empresas estão sujeitas a maiores exigências quanto à legislação ambiental vigente impulsionando-as a implantar sistemas de reúso de efluentes. Apesar de representar uma importante atividade econômica, a indústria de laticínios é responsável pela geração de efluentes líquidos com alto potencial poluidor. O presente trabalho teve como objetivo a redução de contaminantes e melhoria da biodegradabilidade de efluentes de laticínios utilizando tratamentos combinados, em destaque, coagulação/floculação, processos com membranas e oxidação/redução química fotocatalítica. Os efluentes foram provenientes de uma indústria da região, oriundos da etapa de nanofiltração do soro ultrafiltrado. Eles foram divididos em duas correntes, denominadas de concentrado de nanofiltração (corrente 1) e permeado de nanofiltração (corrente 2). Para o tratamento da corrente 1 foi proposto inicialmente coagulação/floculação utilizando diferentes agentes coagulantes naturais (quitosana, derivado de tanino e extrato de moringa), seguido do uso de processos com membranas do tipo microfiltração (0,40 ?m em polieterimida) e ultrafiltração (50 kDa em polietersulfona). Para a corrente 2 foi proposto a utilização de Processos Oxidativos e Redutivos Avançados. Em todas as etapas foi utilizada a Metodologia da Superfície de Resposta para identificação das condições otimizadas. Para o tratamento de coagulação/floculação da corrente 1 foram avaliadas as influências do pH, dos coagulantes naturais e da agitação sobre as variáveis resposta reduções de carbono orgânico total (COT), demanda química de oxigênio (DQO) e turbidez. Na condição indicada como ótima foram alcançadas reduções de 18,3% de COT, 12,7% de DQO e 19,6% de turbidez. A partir da condição otimizada a corrente 1 foi submetida aos processos com membranas, sendo selecionada a microfiltração como melhor tratamento. O uso dessas membranas possibilitou reduções de 1,25% em COT, 5,21% em DQO e 87,4% em turbidez. A combinação destas tecnologias possibilitou a eliminação de 20,1%, 18,0%, 89,8% em COT, DQO e turbidez, respectivamente. Para o tratamento da corrente 2 foram utilizados diferentes tipos de processos oxidativos avançados sendo eles, foto-Fenton (íons ferrosos) e foto-Fenton avançado (uso de ferro metálico). Nestes casos foram avaliadas a influência das concentrações de peróxido de hidrogênio e íon ferroso e ferro metálico considerando como variáveis resposta reduções de COT e DQO. Os resultados otimizados obtidos para o POA foto-Fenton permitiram reduções de 89,9% em COT e 50,8% em DQO, enquanto os resultados otimizados para POA foto-Fenton avançado foram reduções de 74,9% de COT e 41,0% de DQO. / Through the paradigm changes related to environmental management and rising costs of effluent discharge, water abstraction and treatment, industries undergo innovation processes that result in better use of resources and greater reduction in costs. Moreover, companies are submitted to greater requirements regarding environmental regulations driving them to deploy reuse of wastewater systems. Despite representing an important economic activity, the dairy industry is responsible for producing wastewater with high pollution potential. The present work was carried out in order to reduce contaminants and improve the biodegradability of dairy effluent by using an hybrid wastewater treatment based on coagulation/flocculation, membrane process and photocatalytic chemical oxidation/reduction. The effluents came from a regional industry and originating from the nanofiltration step of an ultrafiltrate whey. They were divided into two streams, called nanofiltration concentrate (stream 1) and nanofiltration permeate (stream 2). For the treatment of stream 1 was initially proposed coagulation/flocculation using different natural coagulant agents (chitosan, derivative tannin and moringa extract), followed by membrane processes type of microfiltration (0.40 ?m in polyetherimide) and ultrafiltration (50 kDa in polyethersulfone). For the stream 2 Advanced Oxidation and Reductive Processes were performed. In all steps of the work Response Surface Methodology was used to identify the optimum conditions. For the coagulation/flocculation treatment, the influence of the pH, natural coagulants and agitation were evaluated on the response variables total organic carbon (TOC), chemical oxygen demand (COD) and turbidity reductions. The optimized results reduced of 18.3% TOC, 12.7% COD and 19.6% turbidity. From the indicated condition stream 1 was submitted to membrane processes, being selected the microfiltration as the best treatment. The use of theses membranes provided 1.25% TOC, 5.21% COD and 87.4% turbidity reductions. The combination of these technologies has enabled the elimination of 20.1%, 18.0%, 89.8% in TOC, COD and turbidity, respectively. For the treatment of the stream 2 different types of Advanced Oxidation Processes were used being them, photo-Fenton (ferrous ions) and advanced photo-Fenton (metallic iron). In this cases the influence of the hydrogen peroxide, ferrous ion and metallic iron concentrations were evaluated, considering as response variables TOC and COD reductions. The optimized results for the photo-Fenton AOP allowed 89.9% TOC and 50.8% COD reductions, while the results optimized for advanced photo-Fenton AOP were 74.9% TOC and 41.0% COD reductions.

Por meio das mudanças de paradigmas relacionados à gestão ambiental e elevação dos custos de lançamento de efluente, captação e tratamento de água, as indústrias passam por processos de inovação que resultam em melhor utilização dos recursos e maior diminuição dos custos. Além disso, as empresas estão sujeitas a maiores exigências quanto à legislação ambiental vigente impulsionando-as a implantar sistemas de reúso de efluentes. Apesar de representar uma importante atividade econômica, a indústria de laticínios é responsável pela geração de efluentes líquidos com alto potencial poluidor. O presente trabalho teve como objetivo a redução de contaminantes e melhoria da biodegradabilidade de efluentes de laticínios utilizando tratamentos combinados, em destaque, coagulação/floculação, processos com membranas e oxidação/redução química fotocatalítica. Os efluentes foram provenientes de uma indústria da região, oriundos da etapa de nanofiltração do soro ultrafiltrado. Eles foram divididos em duas correntes, denominadas de concentrado de nanofiltração (corrente 1) e permeado de nanofiltração (corrente 2). Para o tratamento da corrente 1 foi proposto inicialmente coagulação/floculação utilizando diferentes agentes coagulantes naturais (quitosana, derivado de tanino e extrato de moringa), seguido do uso de processos com membranas do tipo microfiltração (0,40 ?m em polieterimida) e ultrafiltração (50 kDa em polietersulfona). Para a corrente 2 foi proposto a utilização de Processos Oxidativos e Redutivos Avançados. Em todas as etapas foi utilizada a Metodologia da Superfície de Resposta para identificação das condições otimizadas. Para o tratamento de coagulação/floculação da corrente 1 foram avaliadas as influências do pH, dos coagulantes naturais e da agitação sobre as variáveis resposta reduções de carbono orgânico total (COT), demanda química de oxigênio (DQO) e turbidez. Na condição indicada como ótima foram alcançadas reduções de 18,3% de COT, 12,7% de DQO e 19,6% de turbidez. A partir da condição otimizada a corrente 1 foi submetida aos processos com membranas, sendo selecionada a microfiltração como melhor tratamento. O uso dessas membranas possibilitou reduções de 1,25% em COT, 5,21% em DQO e 87,4% em turbidez. A combinação destas tecnologias possibilitou a eliminação de 20,1%, 18,0%, 89,8% em COT, DQO e turbidez, respectivamente. Para o tratamento da corrente 2 foram utilizados diferentes tipos de processos oxidativos avançados sendo eles, foto-Fenton (íons ferrosos) e foto-Fenton avançado (uso de ferro metálico). Nestes casos foram avaliadas a influência das concentrações de peróxido de hidrogênio e íon ferroso e ferro metálico considerando como variáveis resposta reduções de COT e DQO. Os resultados otimizados obtidos para o POA foto-Fenton permitiram reduções de 89,9% em COT e 50,8% em DQO, enquanto os resultados otimizados para POA foto-Fenton avançado foram reduções de 74,9% de COT e 41,0% de DQO. / Through the paradigm changes related to environmental management and rising costs of effluent discharge, water abstraction and treatment, industries undergo innovation processes that result in better use of resources and greater reduction in costs. Moreover, companies are submitted to greater requirements regarding environmental regulations driving them to deploy reuse of wastewater systems. Despite representing an important economic activity, the dairy industry is responsible for producing wastewater with high pollution potential. The present work was carried out in order to reduce contaminants and improve the biodegradability of dairy effluent by using an hybrid wastewater treatment based on coagulation/flocculation, membrane process and photocatalytic chemical oxidation/reduction. The effluents came from a regional industry and originating from the nanofiltration step of an ultrafiltrate whey. They were divided into two streams, called nanofiltration concentrate (stream 1) and nanofiltration permeate (stream 2). For the treatment of stream 1 was initially proposed coagulation/flocculation using different natural coagulant agents (chitosan, derivative tannin and moringa extract), followed by membrane processes type of microfiltration (0.40 ?m in polyetherimide) and ultrafiltration (50 kDa in polyethersulfone). For the stream 2 Advanced Oxidation and Reductive Processes were performed. In all steps of the work Response Surface Methodology was used to identify the optimum conditions. For the coagulation/flocculation treatment, the influence of the pH, natural coagulants and agitation were evaluated on the response variables total organic carbon (TOC), chemical oxygen demand (COD) and turbidity reductions. The optimized results reduced of 18.3% TOC, 12.7% COD and 19.6% turbidity. From the indicated condition stream 1 was submitted to membrane processes, being selected the microfiltration as the best treatment. The use of theses membranes provided 1.25% TOC, 5.21% COD and 87.4% turbidity reductions. The combination of these technologies has enabled the elimination of 20.1%, 18.0%, 89.8% in TOC, COD and turbidity, respectively. For the treatment of the stream 2 different types of Advanced Oxidation Processes were used being them, photo-Fenton (ferrous ions) and advanced photo-Fenton (metallic iron). In this cases the influence of the hydrogen peroxide, ferrous ion and metallic iron concentrations were evaluated, considering as response variables TOC and COD reductions. The optimized results for the photo-Fenton AOP allowed 89.9% TOC and 50.8% COD reductions, while the results optimized for advanced photo-Fenton AOP were 74.9% TOC and 41.0% COD reductions.

Orientador: Wilson de Figueiredo Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T10:39:52Z (GMT). No. of bitstreams: 1 Andrade_JulianodeAlmeida_M.pdf: 3254677 bytes, checksum: 72d1e108844df115bda11c77f7fd1337 (MD5) Previous issue date: 2005 / Mestrado / Quimica Analitica / Mestre em Química

The chemical oxygen demand (COD) removal efficiency for treatment of an oil-water emulsion from the machinery industry using Fenton's reagent was investigated. The optimal [H 2 O 2 ]/[Fe 2+ ] molar ratio for COD removal was 3. An orthogonal test was designed based on the optimal molar [H 2 O 2 ]/[Fe 2+ ] ratio to evaluate the significance of four parameters relevant to the treatment process, namely, H 2 O 2 dosage, initial pH, oxidation time and coagulation pH. The influence of the following parameters on COD removal efficiency decreases as follows: H 2 O 2 dosage > oxidation time > coagulation pH > initial pH. The COD removal efficiency was investigated based on the most important single-factor parameter which was H 2 O 2 dosage, as discovered in the orthogonal test. A well-fitted empirical correlation was obtained in the single-factor analysis and up to 98% COD removal was attained using 50 mM H 2 O 2 . With the increase of H 2 O 2 dosage up to 50 mM, the COD removal efficiency increased rapidly due to a higher generation of hydroxyl radicals. However, this effect becomes less significant as the dosage of H 2 O 2 increases. This effect might be attributed to the consumption of hydroxyl radicals with excess H 2 O 2 . The coagulation function of Fenton's reagent was confirmed by scanning electron microscope (SEM). Using the doses and conditions identified in this study, the treated oil-water emulsion can be discharged according to Chinese Standard JS-7740-95.

This dissertation is about treatment of the nonbiodegradable organic content of landfill leachate by chemical oxidation combined with biological treatment. It is divided into three parts. In the first part, ferrate was compared to Fenton's reagent for the purpose of removing non-biodegradable organic compounds from mature leachate. Oxidation conditions (time, pH, and dose) were optimized to yield maximum organic removal using two leachate samples from 20 and 12-year old solid waste cells. Results from this research demonstrated that ferrate and Fenton's reagent had similar optimum pH ranges (3-5), but different organic removal capacities, ranging from 54 to 79 % of initial leachate organic contents. An advantage of ferrate was that it was relatively effective over a wide pH range (Fenton's reagent lost its reactivity outside optimum pH range). Advantages associated with Fenton's reagent include a higher organic removal capacity, production of more oxidized organic compounds (measured as chemical oxygen demand/dissolved organic carbon), and production of more biodegradable byproducts (measured as 5-day biochemical oxygen demand/chemical oxygen demand). Finally, both treatments were found to oxidize larger molecules (>1000 dalton) and produce smaller molecules, as indicated by an increase in smaller molecule contribution to organic carbon. In part two, effects of Fenton's reagent treatment on biodegradability of three landfill leachates collected from a Florida landfill were evaluated using biochemical oxygen demand (BOD), biochemical methane potential (BMP), and tertamethylammonium hydroxide (TMAH) thermochemolysis gas chromatography/mass spectrometry (GC/MS). The hypothesis was that Fenton's reagent will remove refractory compounds that inhibit biodegradation and will produce smaller, more biodegradable organic molecules which will result in an increase in BOD and BMP values. Both BOD and BMP results demonstrated that Fenton's reagent treatment did not convert mature leachate to biodegradable leachate, as indicated by a low BOD5 expressed as C /dissolved organic carbon (DOC) ratio of almost 0.15 in treated samples and a low net methane production / theoretical methane potential (less than 0.15). Ultimate BOD only slightly increased. However the first-order BOD reaction rate increased by more than five fold, suggesting that Fenton's reagent removed refractory and inhibitory compounds. BMP results demonstrated that the ratio of CO2/CH4 produced during anaerobic biodegradation did not increase in treated leachate (compared to untreated), indicating that small biodegradable organic acids produced by oxidation were removed by coagulation promoted by Fenton's reagent. Finally, the TMAH thermochemolysis results showed that several of the refractory and inhibitory compounds were detected fewer times in treated samples and that carboxylic acids did not appear in treated samples. In the third part of this dissertation the application of flushing/Fenton's reagent oxidation to produce sustainable solid waste cells was evaluated. A treatment similar to pump and treat process utilizing Fenton's reagent on-site treated leachate combined with in-situ aeration was proposed. Treated leachate would be recycled to the landfill cell flushes releasable nonbiodegradable carbon from the cell and oxidizes it externally. This technique was demonstrated to have treatment cost and time benefits over other alternatives for producing completely stable solid waste cells such as anaerobic flushing and biological and/or mechanical pretreatment of solid waste (used in the EU).

A presença de substâncias húmicas em águas destinadas ao abastecimento tem ocasionado diversos problemas, entre eles a formação de subprodutos halogenados, principalmente quando se emprega a pré-oxidação com cloro. Com o reagente de Fenton não há a possibilidade de formação desses indesejáveis compostos halogenados, pois o forte poder oxidativo do reagente de Fenton é devido ao radical hidroxila (OH). Aliado a isto, com o mesmo produto químico se pode ter a pré-oxidação e coagulação de compostos orgânicos, pois o reagente de Fenton consiste na aplicação de íons de Fe+2 e peróxido de hidrogênio em meio ácido, sendo o Fe+2 oxidado a Fe+3. Como esses íons formam espécies hidrolisadas que atuam como coagulantes, o reagente de Fenton pode ter a dupla função de oxidação e coagulação nos processos de tratamento. Por isso, neste trabalho foi proposta uma metodologia para emprego do reagente de Fenton como agente coagulante no tratamento de águas contendo cor elevada causada pela introdução de substâncias húmicas extraídas de turfa. Além disto, foi estudado o efeito da massa molecular das substâncias húmicas na eficiência da coagulação, floculação e flotação de águas; para isto foram preparadas 4 águas distintas apresentado a mesma cor verdadeira, mas com substâncias húmicas de diferentes massas moleculares, obtidas por fracionamento por ultrafiltração. Por meio da otimização da dosagem de coagulante e respectivo pH de coagulação e posterior construção dos diagramas de coagulação para cada água de estudo, verificou-se que a água preparada com as substâncias húmicas de menor massa molecular apresentou maior grau de dificuldade para tratamento, requerendo dosagens de coagulante (reagente de Fenton) bem mais elevadas em relação às águas preparadas com substâncias húmicas de maior massa molecular. Adicionalmente, foram realizados ensaios de filtração em areia após a flotação, procurando-se simular tratamento em ciclo completo, tendo sido constatado que com o reagente de Fenton empregado como agente coagulante, a água filtrada atendeu ao padrão de potabilidade vigente no Brasil em relação aos parâmetros medidos (cor aparente < ou = 3 uH, turbidez < 0,5 uT e ferro total residual < 0,005 mg/L). Os valores de absorvância e carbono orgânico total da água filtrada também foram muito pequenos, indicando que a formação dos subprodutos da desinfecção com cloro seriam insignificantes. / Humic substances\' presence in water destined for supply has brought many problems, such as halogenated byproducts formation, mainly when chlorine is used as preoxidant. With Fenton\'s reagent there is no formation possibility of these undesirable halogenated compounds, since the strong oxidative power of Fenton\'s reagent is due to hydroxyl radical (OH). In addition, with the same chemical product, it is possible to have the preoxidation and coagulation of organic compounds, because Fenton\'s reagent consists of Fe+2 ions and hydrogen peroxide application under acid conditions, with Fe+2 oxidized to Fe+3. Since these ions form hydrolyzed species that act as coagulants, Fenton\'s reagent can have the double function of oxidation and coagulation on treatment processes. Because of this, the current work proposed a methodology to use Fenton\'s reagent as coagulant agent in the treatment of waters having high true color caused by the introduction of humic substances extracted by peat. Besides this, humic substances molecular weight effect on coagulation, flocculation and flotation of waters was studied; for this, 4 distinct waters having the same true color were prepared, but with different humic substances molecular weights, obtained by ultrafiltration fractioning. Through optimization of coagulant dosage and respective coagulation pH and posterior construction of coagulation diagrams for each studied water, it was verified that the water prepared withthe smallest molecular weight humic substances was more difficult to treat, requiring higher coagulant (Fenton\'s reagent) dosages compared with the waters prepared with larger molecular weight humic substances. Furthermore, experiments of filtration after flotation were carried out, trying to simulate a complete cycle treatment, which verified that with Fenton\'s reagent, employed as coagulant agent, the filtered water reached the brazilian potable standards concerning the measured parameters (apparent color < ou = 3 HU, turbidity < 0.5 TU and residual total iron < 0.005 mg/L). The absorbance and total organic carbon values of filtered water were also very low, indicating that the disinfection byproducts formation with chlorine would be insignificant.

Ce travail de thèse est axé sur l'élaboration de techniques de bioremédiation des sols contaminés par les Polluants Organiques Persistants (POP) en particulier sur deux familles de polluants : les Hydrocarbures Aromatiques Polycyliques et les dioxines (PCDD/F). La dégradation des POP présente deux obstacles majeurs à l'efficacité des traitements biologiques par voie fongique : la faible biodisponibilité des POP et la difficulté d'amorcer l'oxydation de molécules aussi stables chimiquement. Afin de lever ces verrous technologiques, nous proposons de coupler une oxydation chimique douce à l'oxydation biologique par les champignons telluriques saprotrophes et d'utiliser l'amidon pour améliorer la proximité spatiale entre le polluant et les réactifs d'oxydation. La première partie de ce travail de thèse consiste à fonctionnaliser de l'amidon de pomme de terre par la 1,4-butane sultone et l'anhydride 2-octén-1-ylsuccinique selon différentes conditions de synthèses. En comparaison avec l'amidon natif, un des produits obtenus, P9*, possède des propriétés surfactantes très intéressantes pour notre étude. En effet, P9* augmente la solubilité aqueuse de l'amidon par un facteur de 35 (22,60 g.L⁻¹) et stimulent 33 fois la solubilisation aqueuse du benzo[a]pyrène (BaP). Pour la seconde partie, l'utilisation d'un système d'étude simplifié où le champignon est cultivé en milieu minéral en conditions axéniques nous a permis de déterminer les paramètres (souche fongique, type et dose d'oxydant chimique) optimaux pour l'élaboration d'une méthode de dégradation des POP au laboratoire. Des études comparatives de dégradation du BaP sont donc réalisées in vitro par différents processus d'oxydation chimique (réaction de Fenton) et/ou biologique. Le couplage des deux procédés conduit à une dégradation du PaP de 40,0%. De plus, l'encapsulation du BaP par les nanosphères d'amidon P9* permet une dégradation du polluant de 64,6% par le réactif de Fenton. Deux souches fongiques (Penicillium brasilianum et Fusarium solani) sont ensuite utilisées pour des essais de dégradation conduits au laboratoire en microcosmes de sols historiquement contaminés par les PCDD/F. L'inoculation de la souche endogène P. brasilianum en présence de copeaux de carton comme agent structurant a conduit à une diminution de la toxicité des PCDD/F de 40,5% après seulement 2 mois d'incubation par rapport au sol témoin. Ce travail de thèse ouvre ainsi de nouvelles perspectives de techniques de remédiation des sols pollués par les POP à faible coût économique et respectueuses de l'environnement. / This thesis work deals with the development of bioremediation techniques for contaminated soils by Persistent Organic Pollutants (POPs) such as : Polycyclic Aromatic Hydrocarbons and dioxins (PCDD/F). The degradation of POPs has two main obstacles to efficient biological treatments by fungi : the low bioavailability of POPs and the difficulty of initiating the oxydation of molecules as stable as others. To overcome these technological barriers, we propose to couple a mild chemical oxidation to biological oxidation by saprotrophic telluric fungi and to use starch to improve the spatial proximity between the pollutant and oxidizing reagents. The first part of this study is to functionalize native potato starch by 1,4-butane sultone and 2-octenyl-1-succinic anhydride according to different synthesis conditions. In comparison with native starch, one of the processed products, P9*, has very interesting surfactant properties for our study. Indeed, P9* increases starch apparent aqueous solubility by a factor of 65 (22.60 g.L⁻¹) and stimulates 33-fold benzo[a]pyrene (BaP) aqueous solubilization. For the second part, the use of a simplified study system where the fungus is cultivated in mineral medium under axenic conditions allowed us to determine the best parameters (fungal strainsn type and dose of chemical oxydant) for the development of a POPs degradation method in the laboratory. Comparative studies of BaP degradation are therefore carried out in vitro by different processes of chemical (Fenton's reagent) and/or biologial oxidation. The coupling of the two processes leads to a BaP degradation of 40.0%. Moreover, the BaP encapsulation by starch nanospheres P9* allows a pollutant degradation of 94.6% by the Fenton reagent. Two fungal strains (Penicillium brasilianum and Funsarium solani) are then used for the degradation lab experiment in historically PCDD/F contaminated soil microcosms. the inoculation of the endogene strain P.brasilianum in presence of cardboard chips as a bulking agent led to a decrease in PCDD/F toxicity of 40.5% after only two months of incubation compared to the controm soil. This PhD work draws new perspectives for remediation techniques of contaminated soils by POPs that are cost-effective and environmentally friendly.