Du fait de sa consommation en plein essor et d’une élimination partielle par les procédés conventionnels de traitement des eaux, l'ibuprofène, un médicament anti-inflammatoire non stéroïdien, a été détecté dans les ressources en eau, suscitant de plus en plus d'inquiétude quant à son impact possible sur l'environnement et la santé. Par ailleurs, les procédés d'oxydation avancée (POA), parmi lesquels la réaction Fenton, ont montré d’excellents résultats pour l'élimination de divers composés organiques. Traditionnellement basé sur l'utilisation du peroxyde d'hydrogène et des ions ferreux en solution, l'application à grande échelle de ce POA est encore limitée par une fenêtre de pH étroite (2 à 4) et une récupération difficile du catalyseur à base de fer. Ce travail a étudié l'oxydation Fenton de l'ibuprofène et l'activation de la réaction par irradiation ultrasonore (US) et rayonnement ultraviolet/visible (UV/Vis) et de manière à abaisser la concentration de fer dissous ou à améliorer l'activité de catalyseurs hétérogènes. A cet effet, on a d'abord évalué l'efficacité des POA individuels homogènes (sonolyse, photolyse, sono- et photo-oxydation avec H2O2, oxydation Fenton), en fonction de paramètres opératoires tels que la longueur d'onde lumineuse et la fréquence ultrasonore. Ensuite, on a examiné leurs combinaisons deux-par-deux et globale (sonophotolyse, oxydation sono-, photo- et sono-photo- Fenton) en mettant l'accent sur l'identification d'effets synergiques. En particulier, les oxydations US/Fenton et Vis/Fenton se sont révélées plus efficaces que la somme des procédés individuels grâce à la sono- et photo-régénération des ions ferreux. Ces résultats ont également servi de référence pour l'évaluation des systèmes hétérogènes. Parmi les solides testés, on a montré qu’une zéolite dopée au fer (de type Fe/ZSM5) était un catalyseur prometteur pour l'oxydation de l'ibuprofène par le peroxyde, en raison d'une efficacité élevée à pH naturel et d’une faible lixiviation du fer. Cependant, dans ce cas, on n’a observé au mieux qu'une addition d’effets des ultrasons ou de la lumière et de l'oxydation Fenton hétérogène. Outre la conversion du polluant et du carbone organique total (COT), la formation des principaux produits de dégradation a été suivie pour différents procédés et des voies possibles de dégradation ont été proposées. L’effet matrice a également été examiné en utilisant un effluent de station, qui a eu pour conséquence de réduire la performance de tous les procédés d'oxydation, en raison d'un pH tampon alcalin ou de l’atténuation de la lumière. / Due to booming consumption and only partial removal by conventional water treatment processes, ibuprofen, a non-steroidal anti-inflammatory drug, has been detected in water resources, raising increasing concerns for possible environmental and health impact. On the other hand, advanced oxidation processes (AOPs), among which Fenton reaction, have shown successful results forremoval of various organic compounds. Traditionally based on the use of hydrogen peroxide and ferrous ions in solution, large-scale application of this AOP is still limited by narrow pH window (2 to 4) and uneasy recovery of iron catalyst. This work investigated Fenton-based oxidation of ibuprofen, and reaction activation by ultrasound (US) irradiation and ultraviolet/visible light (UV/Vis) so as to lower the required concentration of dissolved iron catalyst or improve the activity of heterogeneous counterparts. To that purpose, the efficacy of individual homogeneous AOPs (sonolysis, photolysis, ultrasound/H2O2, light/H2O2, Fenton oxidation) was evaluated first, varying operating parameters such as light wavelength and ultrasound frequency. Then, their two-by-two and overall combinations (sonophotolysis, sono-Fenton, photo-Fenton and sono-photo-Fenton oxidation) were examined with emphasis on the identification of synergistic effects. In particular, combined US/Fenton and Vis/Fenton oxidation were found more effective than the sum of individualprocesses due to sono- and photo-regeneration of ferrous ions. These results also served as a reference for the assessment of heterogeneous systems. Among tested solids, iron-containing zeolite (Fe-ZSM5 type) was shown to be a promising catalyst for peroxide oxidation of ibuprofen due to high efficiency at natural pH and low iron leaching. However, in this case, no more than additive effects was observed between ultrasound/light irradiation and heterogeneous Fenton oxidation. Beside pollutant and Total Organic Carbon conversion, main degradation products were monitored for different processes and some plausible degradation pathways were proposed. Water matrix impact was also addressed using wastewater plant effluent, which resulted into hindered performance of all oxidation processes either due to alkaline buffer or light attenuation effect.

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In this master thesis, the feasibility of Fenton-oxidation for the decolorization of reactive dyed cotton is investigated as a potentially environmental-friendly preparatory treatment for mechanical/chemical recycling. Raw, knitted cotton is dyed with a black and a blue dye, whereafter preliminary tests are performed to investigate the influence of increasing Fenton- solution concentrations and different iron-sources on the efficiency of the discoloration, without carrying out complete optimization of the process-parameters. Based on the preliminary test-results, Fenton-treatments of the reactive-dyed cotton are upscaled, with discoloration efficiencies of 62 and 73% (for the black- and blue-dyed cotton respectively). Thermal analysis (TGA, DSC and FTIR) and mechanical analysis (tensile tests and shredding of the fabric) of the upscaled treated samples are performed, and the results indicate no major alterations of the main cellulosic structure of the cotton fibers. However, besides the degradation of the dye-molecules, also some oxidation (and therefore damage) of the cellulose-chains of the cotton fibers occurs, leading to reduced mechanical properties. Although this facilitates the mechanical recycling process, it possibly also reduces the quality of the re-spun yarns. Nevertheless, the Fenton-oxidation in the context of decolorization of reactive-dyed cotton forms an interesting future research-topic with many opportunities and prospects for increasing the efficiency and sustainability of the recycling process, and therefor increasing the sustainability of the textile industry in general.

This study explores the efficacy of two advanced oxidation processes for generation of hydroxyl radicals to promote degradation of emerging contaminants. Drought and water shortage have become pressing issues caused by our world’s changing climate. Water reclamation and reuse are increasingly important options for relieving this water stress. Water reuse runs the risk of reintroducing recalcitrant compounds that can accumulate in our bodies and environment. Advanced treatment methods that degrade these compounds are vital to protect our health and the health of the environment while providing necessary water resources. Advanced oxidation processes (AOPs) have shown great promise for removing recalcitrant compounds through the production of highly reactive hydroxyl radicals (·OH). This study investigated two AOPs for their production of ·OH as indicated by the probe compound pCBA. One of the AOPs examined was a proprietary device that utilizes ambient air and UV to generate singlet oxygen, which subsequently produces ·OH in water. The other is a more common method that combines UV and ozone (O3) to produce ·OH. The proprietary method was not found to produce notable hydroxyl radicals compared to the UV/O3 AOP. The UV dose of the UV/O3 AOP was also altered to analyze the impact on hydroxyl radical production and removal of a representative emerging contaminant, diclofenac (DCF). The sleeves made to alter the UV dose were not found to change the UV dose enough to show a consequential difference in degradation for the fluence indicator atrazine (ATZ) or the emerging contaminant DCF. Further testing with thicker sleeves would be important to determine the necessary amounts of UV and reasonably scale this technology for a water treatment facility.

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The Department of Defense (DoD) has numerous sites that contain groundwater contaminated with 2,4,6-trinitrotoluene (TNT). The currently applied technologies for treating TNT contaminated waters are carbon adsorption and chemical oxidation. Carbon adsorption is a non-destructive technology, which could create future liability issues and is inefficient at relatively low TNT concentrations. On the other hand, application of chemical oxidation for the treatment of TNT contaminated water generates trinitrobenzene (TNB), a by-product of the incomplete oxidation of TNT. TNB is regulated as strictly as TNT. Additionally, over 70% of the reactor required treatment time for meeting target levels is due solely for TNB removal. This study evaluated the potential integration of zero-valent metallic species and advanced oxidation for the treatment of waters contaminated with TNT. The idea was to reduce treatment time, and thus, operational costs, when advanced oxidation is used as a stand-alone treatment technology by reducing TNT prior to oxidation. The use of zero-valent metals as the first treatment step transformed TNT into reduced organic compounds which were easily oxidized. The effectiveness of zinc, iron, nickel, copper, and tin as TNT reducing agents was evaluated. Zinc and iron were selected for further study based on their performance degrading TNT. Then, the reduction mechanism (pathway) and associated by-products of TNT reduction using zinc were examined using a zinc specimen manufactured by Sigma Corporation. Three amines were identified during reduction : 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, and 2,4-diamino-toluene. Other intermediates were observed but not identified. Many of these reduction by-products adsorbed strongly onto the metal surface, significantly reducing the rate of TNT degradation during aging experiments. The aging of the metallic species was modeled using a power decay law parameter with the rate expression for TNT degradation. Corrosion promoters such as KCl addition, ozonation, and peroxone were evaluated as alternatives to reactivate zinc and iron to achieve steady TNT degradation. The addition of KCl performed significantly better than ozonation and peroxone. Furthermore, addition of KCl during the reduction step using iron or zinc generated organics that were successfully mineralized by ozonation or peroxone.

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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. / Civil Engineering