Academic literature on the topic 'Photo-Fenton'
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Journal articles on the topic "Photo-Fenton"
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Liang, Lihua, Lin Ji, Zhaoyan Ma, et al. "Application of Photo-Fenton-Membrane Technology in Wastewater Treatment: A Review." Membranes 13, no. 4 (2023): 369. http://dx.doi.org/10.3390/membranes13040369.
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Photo-Fenton coupled with membrane (photo-Fenton-membrane) technology offers great potential benefits in future wastewater treatment because it can not only degrade refractory organics, but also separate different pollutants from water; additionally, it often has a membrane-self-cleaning ability. In this review, three key factors of photo-Fenton-membrane technology, photo-Fenton catalysts, membrane materials and reactor configuration, are presented. Fe-based photo-Fenton catalysts include zero-valent iron, iron oxides, Fe-metal oxides composites and Fe-based metal–organic frameworks. Non-Fe-based photo-Fenton catalysts are related to other metallic compounds and carbon-based materials. Polymeric and ceramic membranes used in photo-Fenton-membrane technology are discussed. Additionally, two kinds of reactor configurations, immobilized reactor and suspension reactor, are introduced. Moreover, we summarize the applications of photo-Fenton-membrane technology in wastewater, such as separation and degradation of pollutants, removal of Cr(VI) and disinfection. In the last section, the future prospects of photo-Fenton-membrane technology are discussed.
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Miller, Christopher J., Susan Wadley, and T. David Waite. "Fenton, photo-Fenton and Fenton-like processes." Water Intelligence Online 16 (May 15, 2017): 297–332. http://dx.doi.org/10.2166/9781780407197_0297.
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Joodi, Nada Sabeeh, and Nagam Obaid Kariem. "Study of treating the vegetable oils in artificial water using advanced oxidation process." IOP Conference Series: Earth and Environmental Science 1120, no. 1 (2022): 012031. http://dx.doi.org/10.1088/1755-1315/1120/1/012031.
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Abstract AOPs homogenized advanced oxidation process was studied in Fenton and Photo-Fenton on the treatment of artificial water from vegetable oil contaminants. Several variables were studied: time, pH, mixing speed, and a dose of catalysis (Fe2SO4.7H2O).The best conditions are obtained by studying experiments. Fenton and Photo-Fenton process work at an acidic medium (pH=3.5). The optimum mixing speed at (1000 rpm) for the Photo-Fenton process and (500 rpm) for the Fenton. When concentration of H2O2 was (500 mg/L) obtained the concentration of Fe2SO4.7H2O for the photo-Fenton process = (50 mg/L), and for the Fenton process = (250 mg/L). The Fenton process gave a maximum efficiency of removal of vegetable oils of 95.2% for Corn oil (COD from 12800 to 610 mg/L), 94.5% for Castor oil, while 57.5% for Coconut oil after the total reaction time (180 minutes). The Photo- Fenton process gave an efficiency of removal: 93% for Corn oil (COD from 12500 to 870 mg/L), 83.8% for Castor oil, while 61.6% for Coconut oil. As for the real wastewater, the treatment was acceptable and achieved an efficiency of 89.2%, and 83.8% for Fenton, and Photo-Fenton processes respectively.
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Jain, Abhilasha, Marazban Kotwal, and Saima Khan. "Greener And Expedient Approach for the Wastewater Treatment by Fenton and Photo-Fenton Processes: A Review." Asian Journal of Chemistry and Pharmaceutical Sciences 1, no. 1 (2016): 1. http://dx.doi.org/10.18311/ajcps/2016/6134.
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Advanced Oxidation Processes (AOPs) have emerged as a promising technology for the treatment of wastewaters containing toxic, recalcitrant organic compounds such as dyes, pesticides etc. This review paper focuses on the Fenton and photo- Fenton technique which is one of the most efficient AOPs developed to decolorize and/or degrade organic pollutants. This oxidation method can produce biodegradable intermediates and mineralize complex organic pollutants effectively and efficiently. In this paper Fenton and photo-Fenton methods are categorised into two broad groups as homogeneous and heterogeneous Fenton and photo-Fenton processes. Applications of fundamental and advanced combined Fenton and photo-Fenton processes are also discussed.
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Dugandzic, Ana, Andjelka Tomasevic, Dunja Dabic, et al. "Degradation of nicosulfuron using fenton and fenton-like reactions." Chemical Industry and Chemical Engineering Quarterly 24, no. 3 (2018): 201–8. http://dx.doi.org/10.2298/ciceq170617032d.
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Nicosulfuron, a sulfonylurea herbicide, was subjected to different Fenton reactions at pH of a nicosulfuron aqueous solution (pH 5). Usually, the optimal pH for the Fenton reaction is between 3 and 4, but the addition of acids is not environmentally acceptable. This is the reason why the reactions were performed at a higher pH value than usual. So, classical Fenton and Fenton-like reactions were applied as well as photo-Fenton and photo-Fenton-like reactions. In addition, microwave Fenton and Fenton-like reactions were used in nicosulfuron degradation. Influences of Fe2+ and Fe3+ concentrations, as well as hydrogen peroxide concentrations, were studied. The Fenton reaction was much faster and more efficient than the Fenton-like reaction, while the photo- Fenton reaction proceeded much faster and more efficiently than the Fenton reaction. The microwave-Fenton and microwave-Fenton-like reactions proceeded with increased efficiency in comparison to the Fenton and Fenton-like reactions. The phytotoxicity and acute toxicity of the reaction products of nicosulfuron oxidation by the photo-Fenton reaction were analyzed. The toxicity testing of nicosulfuron treatment by photo-Fenton process showed a decrease in phytotoxicity, while the acute toxicity tests showed that the samples after treatment had lower toxicity.
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Santana, Rayany Magali da Rocha, Graziele Elisandra do Nascimento, Polyana Karynne de Aguiar Silva, et al. "Kinetic and ecotoxicological evaluation of the direct orange 26 dye degradation by Fenton and solar photo-Fenton processes." Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental 22 (August 23, 2018): 5. http://dx.doi.org/10.5902/2236117032254.
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The presence of color in textile effluents has been studied because of the need for more effective treatments. Therefore, advanced oxidative processes (AOP) have been used in the degradation of dyes, as well as in the conversion of organic matter. This study evaluated the degradation of the direct orange 26 textile dye by Fenton and photo-Fenton processes (with natural solar radiation). A statistical analysis, based on factorial 23 indicated the best working conditions, being: [H2O2] = 100 mg·L-1 and pH 3-4, for both AOP in that the [Fe] = 1 e 5 mg·L-1, for photo-Fenton and Fenton, respectively. The results of the kinetic studies demonstrated a good fit to the nonlinear kinetic model proposed by Chan and Chu, with values of R2 > 0,996 (photo-fenton) and R2 > 0,939 (Fenton). The tests performed to evaluate the chemical oxygen demand indicated conversions of 62.05% (Fenton) and 66.41% (photo-Fenton). Finally, the ecotoxicity study indicated that the post-treatment samples were non-toxic to the bacteria Escherichia coli and Proteus mirabilis but showed growth inhibition for Lactuca sativa (Fenton and photo-Fenton) seeds and for Brassica juncea and Portulaca grandiflora (Fenton).
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S. Joodi, Nada, and Nagam O. Kariem. "CORN OIL REMOVAL BY ADVANCED OXIDATION PROCESSES IN COMPARTION WITH CASTOR AND COCONUT OILS." Journal of Engineering and Sustainable Development 25, Special (2021): 3–123. http://dx.doi.org/10.31272/jeasd.conf.2.3.12.
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The AOPs advanced oxidation process has been studied in three ways: (UV/H₂O₂), Fenton, and Photo-Fenton in artificial water treating from vegetable oils. The corn, castor, and coconut oils emulsion were prepared and treated by AOPs. Several variables were studied: time, pH, mixing speed, temperature, the dose of chemicals (H₂O₂ & Fe2SO4.7H2O), and finally the oil concentration. The best conditions were obtained in several experiments where the Fenton and Photo-Fenton process operates in an acidic medium (pH = 3.5), while the UV/H₂O₂ process operates with the neutral medium (pH = 7). The optimum temperature for the Photo-Fenton and UV/H₂O₂ processes is 40°C, and for the Fenton process is 20°C. While there was an effect of mixing speed, higher efficiency was achieved at (1000 rpm) for the Photo-Fenton process and (500 rpm) for the Fenton and UV/H₂O₂ processes. Also, the H₂O₂ concentration was at (500 mg/L) for all processes, when the Fe2SO4.7H2O concentration for the photo-Fenton process = (50 mg/L), and for the Fenton process = (250 mg/L). Oil concentration = (1750 mg/L). Optimum conditions were applied to treat vegetable oils, the Fenton process gave a maximum removal efficiency of 95.2% for corn oil (COD 12800 to 610 mg/L), 94.5% for castor oil, while 57.5% for coconut oil after the total reaction time (180 minutes). The Photo-Fenton process gave removal efficiencies: 93% for corn oil (COD 12500 to 870 mg/L), 83.8% for castor oil, and 61.6% for coconut oil. The UV/H₂O₂ process gave removal efficiencies: 69.8% for corn oil, 32% for castor oil, and 23.4% for coconut oil after the total irradiation time. As real wastewater, the treatment was acceptable and achieved an efficiency of 44.7%, 89.2%, and 83.8% for the UV/H₂O₂, Fenton, and Photo-Fenton processes, respectively.
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Didar Değermenci, Gökçe. "Decolorization of reactive azo dye by fenton and photo-fenton processes in aqueous solution: The influence of operating conditions, kinetics study, and performance comparison." Bulletin of the Chemical Society of Ethiopia 37, no. 1 (2022): 197–210. http://dx.doi.org/10.4314/bcse.v37i1.16.
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ABSTRACT. In this study, the effect of Fenton and photo-Fenton processes, which are advanced oxidation processes that use the hydroxyl radical for the decolorization of Novacron Black from aqueous solutions, on decolorization was investigated. Optimum levels of initial pH, temperature, hydrogen peroxide concentration, initial dyestuff concentration, and iron concentration were determined. Initial pH, Fe2+ concentration, temperature, and initial Novacron Black concentration are the most effective experimental parameters in the decolorization of Novacron Black with Fenton and photo-Fenton processes. While the Novacron Black concentration was 200 mg/L, the H2O2 concentration was 100 mg/L, the initial solution pH was 3, and the temperature was 20 °C, a decolorization efficiency of 82.1% was obtained in the Fenton process at a concentration of 5 mg/L Fe2+, while in the photo-Fenton process at a 2 mg/L Fe2+ concentration, a 94.6% decolorization efficiency was obtained. Upon decolorization of Novacron Black, the photo-Fenton process had a higher removal efficiency than the Fenton process, even at low iron concentrations. From data obtained at various concentrations of initial Novacron Black, the non-linear method was used to determine the decolorization kinetics of Novacron Black. Finally, an economic analysis was carried out to compare the differences in operating costs between Fenton and photo-Fenton processes.
 
 KEY WORDS: Advanced oxidation process, Decolorization, Fenton oxidation, Kinetic model, Photo-Fenton oxidation
 Bull. Chem. Soc. Ethiop. 2023, 37(1), 197-210. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i1.16
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Watcharenwong, Apichon, Kawintra Kongka, Anusara Kaeokan, Chanat Chokejaroenrat, and Chainarong Sakulthaew. "Decolorization of Melanoidin Using Sono–Fenton and Photo–Fenton Processes." Waste 1, no. 2 (2023): 455–67. http://dx.doi.org/10.3390/waste1020027.
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Ethanol production wastewater contains high quantities of dark–brown pigments (melanoidin) that result in low color removal using conventional biological treatments. Advanced oxidation processes (AOPs) are the most documented methods for reducing the color associated with melanoidin. This study examines the degradation of melanoidin using AOPs based on photo–Fenton, sono–Fenton, and sono–photo–Fenton processes. Their effects on decolorization were investigated based on light intensity, ultrasonic frequency, and the iron concentration (Fe2+)–to–H2O2 ratio. This study showed that ultrasonic waves and UV light result in a higher melanoidin decolorization efficiency than Fenton reactions alone. The initial color values were reduced from 5000–5500 ADMI to below 500 ADMI for both processes because the ultrasonic waves and ultraviolet light induced H2O2 breakdown into the 🞄OH radical. Reducing the color of the melanoidin using the photo–Fenton process resulted in a decolorization rate of 0.1126 min−1, which was higher than the rates of both the sono–Fenton and sono–photo–Fenton processes. These results provide proof that the photo–assisted Fenton process is more applicable to treating dye–contaminated water than are other enhancing approaches.
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Wu, C. H., J. T. Wu, and Y. H. Lin. "Mineralization of sulfamethizole in photo-Fenton and photo-Fenton-like systems." Water Science and Technology 73, no. 4 (2015): 746–50. http://dx.doi.org/10.2166/wst.2015.554.
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In this investigation, UV/H2O2, UV/H2O2/Fe2+ (photo-Fenton) and UV/H2O2/Fe3+ (photo-Fenton-like) systems were used to mineralize sulfamethizole (SFZ). The optimal doses of H2O2 (1–20 mM) in UV/H2O2 and iron (0.1–1 mM) in photo-Fenton and photo-Fenton-like systems were determined. Direct photolysis by UV irradiation and direct oxidation by added H2O2, Fe2+ and Fe3+ did not mineralize SFZ. The optimal dose of H2O2 was 10 mM in UV/H2O2 and that of iron (Fe2+ or Fe3+) was 0.2 mM in both UV/H2O2/Fe2+ and UV/H2O2/Fe3+ systems. Under the best experimental conditions and after 60 min of reaction, the SFZ mineralization percentages in UV/H2O2, UV/H2O2/Fe2+ and UV/H2O2/Fe3+ systems were 16, 90 and 88%, respectively. The UV/H2O2/Fe2+ and UV/H2O2/Fe3+ systems effectively mineralized SFZ.
Dissertations / Theses on the topic "Photo-Fenton"
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Wee, Hong Chin, and weehong_chin@yahoo com au. "Greywater treatment by Fenton, Photo-Fenton and UVC/H2O2 processes." RMIT University. Civil, Environmental and Chemical Engineering, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20091127.145052.
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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.
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Yu, Xiangwei. "Optimization strategies for efficient dosage of H2O2 in Fenton and photo-Fenton processes." Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672371.
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This Thesis work addresses the challenge of designing hydrogen peroxide (H2O2) dosage Strategies for improving Fenton and photo-Fenton applications. The determination of the H2O2 dosage scheme that minimizes hydrogen peroxide consumption while meeting the specified treatment outcome is crucial for the practicality of Fenton and photo-Fenton processes, as well as for further understanding the effect of the dosage. A first part of the research addresses this challenge by providing a problem formulation, identifying and discussing objectives and constraints, and the nature of the optimal solution. From this point, the Thesis presents a novel dosage model and a consequent methodology aimed at experimentally optimizing the dosage profile along a discretized time horizon following recipe optimization concepts. The approach is parallel to the numerical solution of the model-based optimization problem posed by H2O2. The methodology is validated in the remediation of a Paracetamol (PCT) solution, and the obtained results are assessed and discussed in regard of the evolution of the concentration of hydrogen peroxide, the contaminant (PCT), and Total Organic Carbon (TOC). The concentration of dissolved oxygen (DO), which is also monitored, allows providing a more comprehensive explanation of the nature of the process. A second part focuses on the practical limitations of this scheme by adopting a hybrid methodology between open and closed loop approaches and it is based on three different stages: (i) one-shot initial H2O2 addition (ii) continuous H2O2 dosage until reaching a specific dissolved oxygen (DO) level and (iii) on-off control of H2O2 dosage using DO slope as control variable. The proposed strategy is validated in the remediation of a Paracetamol solution (100 mg L-1) and the results are assessed using H2O2 consumption and mineralization rate and level as performance criteria. The final tuning of the proposed strategy consists of: (i) only 40% of the stoichiometric H2O2 concentration, (ii) continuous feeding of H2O2 until a 4 mg L-1 DO concentration is attained, and (iii) on-off control dosage selecting DO slope set-points in 0.1 and 0.2 mg L-1 1 min-1. The dosage scheme and settings developed in this second part show an improvement of the process performance by ~ 15% with respect to the same H2O2 amount in a single-addition. Finally, the third part generalizes this strategy by expanding its application and exploring and assessing its performance on different water matrix (natural water and distilled water), different contaminant concentrations, and different contaminants (paracetamol and sulfamethazine) and mixtures. Towards this end, a set of assays were planned and executed involving Paracetamol and Sulfamethazine. In particular, assays performed on sulfamethazine presented higher efficiency (mg of TOC removed per mg of H2O2 consumed), which increased 25-35% with respect to the results obtained with only one-shot initial addition. Furthermore, a deeper analysis of the results allowed detecting and assessing the option of a redesign of the dosage scheme by removing the idea of a specific DO set point and directly addressing the control of the DO slope. Hence, this thesis also opens new research lines in regard to increasing the simplicity and robustness of this efficient control strategy of the photo-Fenton process.<br>Aquest treball de tesi aborda el repte de dissenyar estratègies de dosificació de peròxid d'hidrogen (H2O2) per millorar les aplicacions dels processos Fenton i foto-Fenton. La determinació d'una estratègia de dosificació d'H2O2 que en minimitzi el consum mentre s'assoleixen els objectius del tractament especificat és crucial per a l'aplicació pràctica dels processos de Fenton i foto-Fenton, així com per a la millor comprensió de l'efecte de la dosificació. Una primera part de la investigació aborda aquest repte proporcionant una formulació del problema, identificant i discutint objectius i restriccions, i la naturalesa de la solució òptima. A partir d'aquest punt, la tesi presenta un nou model de dosificació i una metodologia derivada que pretén optimitzar experimentalment el perfil de dosificació al llarg d'un horitzó temporal convenientment discretitzat seguint conceptes d'optimització de receptes. L'enfocament és paral·lel a la solució numèrica del problema d'optimització basat en models i la metodologia que se'n deriva es valida en el tractament d'una solució de paracetamol (PCT). Els resultats obtinguts s'avaluen i es discuteixen en relació amb l'evolució de la concentració de peròxid d'hidrogen, el contaminant (PCT) i el carboni orgànic total (TOC). La concentració d'oxigen dissolt (DO), que també es controla, permet donar una explicació més completa de la naturalesa del procés . Una segona part se centra en les limitacions pràctiques d'aquest esquema mitjançant l'adopció d'una metodologia híbrida entre el control en llaç obert i el control en llaç tancat. La metodologia es basa en tres etapes diferents: (i) addició inicial H2O2 inicial (ii) dosificació contínua d'H2O2 fins a arribar a un determinat nivell d'oxigen dissolt (DO) i (iii) control on-off de la dosi d'H2O2 utilitzant el pendent de DO com a variable de control. L'estratègia proposada es valida en el tractament d'una solució de paracetamol (100 mg L-1) i els resultats s'avaluen utilitzant el consum de H2O2 i la taxa i el nivell de mineralització com a criteris de rendiment. L'ajust final de l'estratègia proposada es concreta de la següent manera: (i) només el 40% de la concentració estequiomètrica de H2O2, (ii) alimentació contínua de H2O2 fins a l'assoliment d'una concentració de 4 mg de L-1 DO i (iii) dosificació sota un control on-off seleccionant els valors de pendent de DO entre 0,1 i 0,2 mg L-1 1 min-1. L'esquema de dosificació i la configuració desenvolupats en aquesta segona part mostren una millora del rendiment del procés d'un 15% respecte al que s'obté amb mateixa quantitat de H2O2 en una única addició. Finalment, la tercera part generalitza aquesta estratègia ampliant la seva aplicació, explorant i avaluant el seu rendiment en diferents matrius d'aigua (aigua natural i aigua destil·lada), diferents concentracions de contaminants, diferents contaminants (paracetamol i sulfametazina) i mescles. Amb aquesta finalitat, es van planificar i executar un conjunt d'assajos que van incloure paracetamol i sulfametazina. En particular, els assajos realitzats amb sulfametazina van presentar una eficiència més elevada (mg de TOC eliminats per mg d'H2O2 consumit), que va augmentar entre un 25 i un 35% respecte als resultats obtinguts amb només una única incorporació inicial. A més, una anàlisi més profunda dels resultats va permetre detectar i avaluar l'opció d'un redisseny de l'esquema de dosificació eliminant la idea d'un punt de referència específic de DO i abordant directament el control del pendent de DO. Per tant, aquesta tesi també obre noves línies de recerca per augmentar la simplicitat i robustesa d'aquesta estratègia de control eficient del procés de foto-Fenton.<br>Enginyeria de processos químics
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Modrzejewska-Baudin, Barbara. "On-line Monitoring of a Photo-Fenton System." Thesis, University of South Wales, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492162.
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A uv photo-Fenton process, utilising immobilised iron catalyst, was studied during the experimental work described here to treat the model recalcitrant waste: nonbiodegradable azo dye Orange II in concentrations ranging from 0.05 to 0.80 mM. The AOP reactor with capacity of 12l and headspace volume of 0.5l was constructed and used to study the oxidation of the dye waste stream during both batch and continuous experiments. The Fenton process was enhanced by light (with radiation centred at 253.7nm) through the decomposition of photo-active Fe(OH)2+, leading to the generation of additional ·OH radicals with concomitant partial recycling of the Fe3+ to Fe2+. The process utilised a novel immobilised Fe catalyst (initially Nafion membrane based and subsequently Fe-Silica fabrics) which allows the reduction of the amount of iron salts required to be fed into the process, reduces sludge production from the process and the risk of iron salts precipitating on the UV lamps. Both the aqueous and gas phase off-line process parameters were evaluated and a novel on-line gas phase monitoring system (analysing carbon dioxide from the complete oxidation of organic matter and oxygen from the self-decomposition of hydrogen peroxide) was also developed and employed. During the latter stages, a novel instrument measuring hydrogen peroxide levels, operating in conjunction with the AOP reactor, was evaluated. The hydrogen peroXide dosing was studied with molar ratios of hydrogen peroxide to Orange II dye within the range of 7.8:1 to .62.5:1. It was established that the optimum ratio for organic carbon removal was 31.25 M H202 to 1 M Orange II dye. Both under-dosing and over-dosing of hydrogen peroxide resulted in a decreased efficiency of the oxidation treatment due to a reduction in the number of hydroxyl radicals available for oxidation. The comparison of oxidation results initiated at both neutral and acidic conditions (pH <3) showed marginally higher efficiency in COD and Toe removal during epxen'ments W.ith lowered pH (0.4% and 3.2%, respectively). It was demonstrated that'In!Tlatl.ng the expen.ments at elevated liquor temperature of approximately 50°C (in contrary to experiments initiated at room temperature) promoted slightly higher efficiency of the photo-Fenton process and carbon removal was on average 2.5% higher during 50°C runs. Iron analyses conducted during the batch experiments showed gradual deterioration of Nafion membranes which led to significant reduction in oxidation efficiency; the TOe removal decreased from 97% to 29%. Subsequently Nafion membranes were replaced by Fe-Silica fabrics, which proved to be better suited to the UV-Fenton process. The comparison of batch and continuous studies indicated a higher efficiency of the photo-Fenton process during the continuous treatment: to reach the same level of TOC removal, the batch experiments reqUired on average 19 minutes more than the continuous experiments with an equivalent hydraUlic retention time (HRT). The oxidation treatment of initially non-biodegradable Orange II solutions (BODs/COD ratio of 0.001) resulted in increased biodegradability and the continuous experiment with HRT of 1.5h was enough to make the waste stream biodegradable (BODs/COD ratio of 0.62). The analysis of oxygen gas suggested that the hydrogen peroxide overdosing lead to the production of oxygen gas; this was likely due to the scavenging of hydroxyl radicals, as the excess hydrogen peroxide was successfully competing with organics for the radicals. In order to evaluate and control the usage of hydrogen peroxide during the oxidation process on waste-stream of varying load and strength, the AOP reactor was used in conjunction with the automated hydrogen peroxide monitor. The principle of the H20 2 monitor's operation was the measurement of the produced volumes of oxygen from the reaction of catalase enzyme with hydrogen peroxide. The monitor's response was found to be linear within the hydrogen peroxide range of 30 - 400 mg H20 2 with R2 correlation of 0.99. After the initial experiments with poor correlation between the off-line spectroscopy measurements and H20 2 monitor (R2 of 0.25), the sample conditioning was introduced. With sample conditioning the correlation with the off-line spectroscopy measurements was greatly improved with the correlation coefficients R2 of 0.957 and 0.995. This would enable the on-line process monitoring of hydrogen peroxide to be implemented in the AOPs.
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Tarkwa, Jean-Baptiste. "Elimination des polluants organiques des effluents industriels aqueux par plasma non-thermique de type glidarc et le procédé photo-Fenton : optimisation des procédés et mécanisme d’oxydation des polluants." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2020/document.
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Cette étude a porté sur l’application de deux procédés d’oxydation avancée photochimiques (plasma d’air humide type glidarc et photo-Fenton) pour le traitement des solutions aqueuses de 4-Chlorophenol et d’Orange G. Les analyses spectroscopique, UV-vis et chromatographique (chromatographie liquide à haute performance) ont été employées pour suivre la dégradation des polluants tandis que le niveau de minéralisation de leur solution a été évalué par la mesure du carbone organique total grâce à un COT-mètre. Le dosage des ions inorganiques a été effectué par chromatographie ionique. Le catalyseur solide (latérite) a été caractérisé par spectroscopie d’absorption atomique, la méthode BET, la diffractométrie aux rayons X (DRX) et les spectroscopies IR et RAMAN. L’étude de l’oxydation du 4-chlorophenol et de l’Orange G par le procédé photo-Fenton a été consacrée à l’optimisation des conditions opératoires de dégradation et de minéralisation. Ainsi, une dégradation complète (100%) de 0,2 mM de 4-Chlorophenol est notée en seulement 4 min de traitement dans les conditions optimales établies (pH = 3 ; 0,1 mM Fe3+ et 6 mM H2O2) ; soit un rapport, R = [H2O2]/[Fe3+] de 60. En revanche, R = 20 à 0,1 mM Fe3+, constitue l’optimum pour la minéralisation, soit 81 % après 180 min de traitement. Au cours de l’oxydation de l’Orange G, l’optimisation s’est basée sur l’utilisation des constantes cinétiques apparentes de dégradation. Ainsi, nous avons établis un rapport optimum de réactifs de Fenton, R = [H2O2]/ [Fe3+] = 13,8 ; soit 6 mM de H2O2 et 0,435 mM de Fe3+. Dans ces conditions, une dégradation complète (100%) de l’Orange G est obtenue en 5 min et une minéralisation de 93 % après 180 min de traitement. Sur la base des produits intermédiaires (aromatiques et aliphatiques) et des ions inorganiques identifiés, il a été proposé un mécanisme de minéralisation de chacun des polluants par les radicaux hydroxyles. L’étude de la dégradation de l’Orange G par le plasma glidarc a visé l’amélioration des performances du glidarc en optimisant les conditions opératoires afin de réduire le coût énergétique. Pour cela, deux catalyseurs (Fe3+ et latérite) ont été ajoutés au système au cours du traitement. Dans les conditions optimales de traitement, des taux de (dégradation et minéralisation) de (17et 6) ; (74 et 25); (100 et 57) et (100 et 82%) ont été enregistrés respectivement en utilisant le glidarc seul ; glidarc/Fe3+(0,2 mM) ; glidarc/photo-Fenton (4 mM H2O2 + 0,2 mM de Fe3+) et glidarc/latérite (3 g L-1), après 60 min de traitement. Enfin l’analyse comparative du coût global de chaque procédé dans les conditions optimales en réactifs et pour une durée de traitement nécessaire à moins 90% de minéralisation de 0,1 mM de solution aqueuse d’Orange G a permis d’obtenir le classement suivant par ordre croissant du coût : plasma/latérite < plasma-photo-Fenton < photo-Fenton<br>This work focused on the application of two photochemical advanced oxidation processes (humid air gliding arc plasma and photo-Fenton) for the treatment of aqueous solutions of 4-Chlorophenol and the azo dye (Orange G). UV-vis spectroscopy and high performance liquid chromatography were used to follow pollutants degradation while the degree of mineralisation of their aqueous solution was estimated using TOC-meter (SHIMADZU). Ionic chromatography was performed to measure the concentration of inorganic ions released to the solution. The solid catalyst (laterite) was characterized by atomic absorption spectroscopy, N2 adsorption/desorption BET method, X-ray diffraction (XRD), Fourier transform infrared and RAMAN spectroscopies. The oxidation of 4-chlorophenol and Orange G by photo-Fenton process was devoted to the optimization of degradation and mineralization operating conditions. Thus, complete (100%) degradation of 0.2 mM 4-chlorophenol is reached at only 4 min of treatment under the established optimum conditions (pH =3, 0.1 mM Fe3+ and 6 mM H2O2) corresponding to the R = [H2O2]/ [Fe3+] of 60. In contrast, R = 20 with (0.1 mM Fe3+), is the optimum ratio allowing 81 % of mineralization, after 180 min of treatment. During Orange G degradation by Photo-Fenton process, the optimization was focused on the use apparent rate constants of degradation. Thus, it was established a ratio R = [H2O2] / [Fe3+] = 13.8; either 6 mM H2O2 and 0.435 mM Fe3+. Under these conditions, a complete degradation (100%) of the Orange G was obtained at 5 min and 93% TOC removal at 180 min of treatment. From the identified organic intermediates (aromatic and carboxylic acids) and leached inorganic ions products, we proposed a plausible mechanism for oxidation of each pollutant by hydroxyl radicals. The degradation of Orange G by gliding arc plasma aimed to improve the performance of glidarc by optimizing the operating conditions in order to reduce energy cost. Therefore, two catalysts (Fe3+ and laterite) were comparatively tested during the treatment of 0.1 mM Orange G aqueous solution. Under optimal conditions, degradation (decays and mineralization) of (17 and 6); (74 and 25); (100 and 57) and (100 and 82%) were recorded respectively using glidarc alone; glidarc/Fe3+(0.2 mM); glidarc/Fe3+(0.2 mM)/H2O2(4 mM) and glidarc/laterite (3 g L-1) systems after 60 min of treatment. Finally, the comparative analysis of the overall cost of each process under optimal operating conditions and for a required time of at least 90% of mineralization of 0.1 mM Orange G aqueous solution, gave the following cost classification : plasma/laterite
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Alvarenga, Rodrigo Neder. "Tratamento de efluente têxtil através de processos redox e separação com membranas combinados." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/97/97137/tde-25102012-134959/.
Full textAbstract:
O processamento têxtil gera grande quantidade de despejos altamente poluidores, contendo valores elevados de carga orgânica, cor acentuada e compostos químicos tóxicos ao homem e ao meio ambiente. Os efluentes têxteis apresentam uma variação muito grande na sua composição devido aos vários tipos de corantes e produtos químicos utilizados e isto faz o seu tratamento ser um problema complexo. Devido a estas implicações, novas tecnologias têm sido buscadas para a degradação ou imobilização destes compostos em efluentes têxteis dentre os quais a combinação de processos oxidativos avançados, redutivo e separação por membranas. Os processos de separação por membranas têm sido cada vez mais aplicados para separação, purificação e concentração de constituintes industriais, principalmente pelo desenvolvimento e eficiência da técnica e redução de custos com o passar dos anos. O processo redutivo utilizando Fe0 é bastante promissor, em função do custo relativamente baixo do ferro metálico e da sua elevada efetividade na degradação de contaminantes ambientais, sendo que após a oxidação do Fe0 a íons Fe2+ e Fe3+ estes íons podem ser aproveitados em sequência nos Processos Oxidativos Avançados (POAs). Os processos oxidativos avançados são tecnologias extremamente eficientes para destruição de compostos orgânicos de difícil degradação. Podem ser consideradas tecnologias limpas, pois não há a formação de subprodutos sólidos e nem a transferência de fase dos poluentes. Os POAs são baseados na geração de radicais fortemente oxidativos, principalmente o radical hidroxila (HOo), que destroem inúmeros compostos de maneira rápida e pouco seletiva, quando comparado aos processos convencionais, conduzindo a mineralização parcial ou completa dos contaminantes. Com o objetivo de estudar o efeito destes processos na melhoria do efluente têxtil foi utilizado um efluente de uma indústria têxtil de grande porte do interior de São Paulo. Ao ser coletado, este efluente foi caracterizado e submetido à permeação por membranas de microfiltração (0,45 μm). Este tratamento possibilitou a redução de 37,7 % do COT e 40,9 % da Área Espectral (200-800 nm) em comparação com o efluente original. O efluente oriundo do tratamento com membranas foi submetido, através de planejamento de experimentos, aos processos oxidativos avançados do tipo foto-Fenton e foto-Fenton avançado (utilizando Fe0) visando à melhoria para despejo ou reúso deste efluente. Na melhor condição de reação foi possível alcançar uma redução de aproximadamente 73,0 % em COT e 93,0 % em área espectral após uma hora de reação para os dois tipos de POAs. A combinação das tecnologias de membranas e processos oxidativos avançados mostrou-se extremamente positiva quanto à melhoria da deste efluente têxtil, possibilitando a redução em torno de 83,0 % do COT e 95,0 % da área espectral.<br>The textile manufacturing generates large amounts of highly polluting sewage containing high levels of organic load, color and chemical compounds toxic to human beings and to the environment. This textile wastewater has a great variation in its composition due to various types of dyes and chemicals used. All these considerations make the textile wastewater treatment a complex problem. Due to these implications, new technologies have been studied for degradation or immobilization of these compounds in textile wastewater among which the combination of advanced oxidative, reductive and separation with membranes processes. The separation processes with membranes have been increasingly applied for separation, purification and concentration of industrial components, mainly development in technology and efficient cost savings over the years. The reductive process using Fe0 is very promising because of the relatively low cost of metallic iron and its high effectiveness in the degradation of environmental contaminants. After the oxidation of Fe0 to Fe2+ and Fe3+ these ions can be used in sequence in the Advanced Oxidative Process (AOPs). The advanced oxidative process technologies are extremely effective for degradation of organic compounds with difficult degradation. It can be considered as a clean technology, because there is no formation of solid subproducts, neither the phase transfer of pollutants. The AOPs are based on the generation of highly oxidative radicals, particularly hydroxyl radical (HOo), which destroys many compounds to a rapid and low selective way compared with conventional process of treatment, leading to partial or complete mineralization of contaminants. A wastewater from a large textile industry in São Paulo was used in order to study the effect of these processes in the improvement of textile wastewater quality. Firstly, the wastewater was characterized and subjected to permeation by microfiltration membrane (0.45 μm). This treatment allowed a reduction of 37.7 % of TOC and 40.9 % of spectral area (200-800 nm) compared to the original wastewater. The wastewater from the treatment with membranes was subjected, through design of experiments, the advanced oxidative processes of the type photo-Fenton and advanced photo-Fenton (using Fe0) aiming to improve the disposal or to reuse of wastewater. In the best experimental condition it was achieved a 73 % in TOC and 93 % in spectral area reduction after one hour of reaction for both types of AOPs. The membrane technologies and advanced oxidative combination process proved to be extremely positive on the textile wastewater quality improvement, resulting in a reduction of around 83 % of TOC and 95 % of spectral area.
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Silva, Thiago Henrique Gomes da. "Acoplamento entre processos biológicos e oxidativos avançados para o tratamento de esgoto sanitário: degradação de fármacos e reúso seguro." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-15092017-111506/.
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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.<br>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.
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Cruz, Gonzalo Angel. "Synthesis and performance of heterogeneous catalysts for Fenton-like and photo-Fenton-like reactions at circumneutral pH." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/404350.
Full textAbstract:
As an essential resource for life and most human activities, water resources protection have become one of the major focuses of scientific community, especially the increasing occurrence of emerging pollutants which have its origin in commonly used pharmaceuticals, personal care products, pesticides and some other anthropogenic origin compounds.
Fenton and photo-Fenton are advanced oxidation processes (AOPs) that have been widely proved on the removal of these compounds, but they are conventionally applied at acidic pH, below 3.0, because these processes involve the use of iron (II) salts, which are not soluble above. Also, the acidic effluents must be neutralized and high amounts of iron sludge are formed in the process.
Current research in the field tries to solve this drawback by focusing in two possible solutions: the use of chelating agents to keep iron soluble at circumneutral pH or the use of heterogeneous catalysts containing iron that can be easily removed and reused after its application.
This work is focused on the study, application and improvement of alginate-based heterogeneous catalysts for conducting photo-Fenton reactions at circumneutral pH.
Initially, the preparation process of the conventionally used Fe(III)/alginate catalyst was optimized by evaluating the effect of the parameters involved on its synthesis. Then, the synthetized catalyst was applied to the abatement of antibiotic sulfamethoxazole (SMX), which was used as reference compound. The reaction mechanism of alginate-based catalysts was proposed according to the results obtained. Also, a deep study about catalyst stability revealed a high dependence with water’s pH. Fe(III)/alginate catalyst proved to release iron when sample’s pH was below alginate’s pKa. Also, due to its organic nature, a significant HO· scavenging effect of alginate itself was observed, which reduced the effective amount of hydroxyl radicals available for the oxidation of the target compound.
Fe(III)/alginate was also tested for disinfection by adjusting the conditions to ensure a minimal iron release. Thus, the contribution of homogeneous reaction was significantly avoided. The catalyst proved being able to be used for disinfection of waters with low organic loads.
In order to improve the Fe(III)/alginate catalyst, some modifications were applied. The first one was the addition of a dehydration stage after its synthesis. The resulting catalyst was tested on the removal of SMX and had a similar effectiveness than the conventionally used Fe(III)/alginate but with a significantly lower iron release, which confirmed its improved stability. This more stable catalyst was also modified by including TiO2, zero valent iron (ZVI) particles or cerium on its structure with the aim of, not only increase its stability, but its
effectiveness. The TiO2 catalyst proved to increase the effectiveness of the overall removal of SMX while the other two modifications did not.
Red volcanic rocks, iron shavings from metallurgical industry, a commercial Fe/Mn/O catalyst and a self-synthetized Fe/Ce/O catalyst were also tested as heterogeneous catalysts for Fenton and photo-Fenton at acidic and neutral pH. These catalysts were selected as inorganic-based ones and were compared to the Fe(III)/alginate dehydrated catalyst when applied to photo- Fenton at neutral pH. Results proved that only volcanic rocks had a significant activity when applied for photo-Fenton at neutral pH, but the effectiveness on the removal of SMX was low in comparison to the alginate-based catalyst. All other catalysts presented too low activity or major drawbacks that made them not suitable for water purification through Fenton-like and photo-Fenton-like processes.<br>Los procesos Fenton y foto-Fenton son procesos de oxidación avanzada (POA) que se basan en la descomposición del peróxido de hidrógeno catalizada por sales de hierro (II), produciendo radicales hidroxilo que son altamente oxidantes. El segundo además incorpora la irradiación con luz ultravioleta en el rango A, cosa que permite acelerar el proceso debido a la recuperación del hierro (II), que durante la reacción principal pasa a hierro (III). Estos procesos se suelen llevar a cabo a pH ácido (pH<3) debido a la baja solubilidad y la poca actividad de las especies de hierro a pH cercanos a la neutralidad.
Este trabajo se centra en el estudio y aplicación de un catalizador heterogéneo de Fe/alginato formado gracias a la propiedad del alginato de formar geles sólidos en presencia de cationes di y trivalentes. En este caso, el Fe(III) actúan como enlace entre cadenas de alginato.
Inicialmente se estudió el proceso de fabricación de este catalizador y se propuso un proceso estándar optimizado para su uso aplicado a la reacción foto-Fenton.
Posteriormente se evaluó su aplicación a la eliminación del antibiótico sulfametoxazol y a la desinfección de bacterias Escherichia Coli. Basándose en los resultados obtenidos se propuso un mecanismo de reacción que además explicaba la inestabilidad observada experimentalmente que producía la liberación de hierro dependiendo del pH del medio de reacción, lo que desencadenaba la vía de reacción homogénea.
Con la intención de mejorar la estabilidad del catalizador, se modificó el proceso de síntesis añadiendo una etapa de deshidratación controlada al final del proceso. Los resultados en su prueba para la reacción foto-Fenton aplicada a la eliminación de sulfametoxazol mostraron que el rendimiento no empeoraba pero mejoraba significativamente su estabilidad.
Para aumentar su eficiencia se probó incorporar cerio, partículas de hierro monovalente y TiO2. Los resultados mostraron que solo el catalizador modificado con TiO2 mejoraba el rendimiento global de la reacción.
Por último, se probaron otros catalizadores heterogéneos (piedras volcánicas, Fe/Ce/O, Fe/Mn/O, limaduras de hierro) aplicados a la reacción foto-Fenton. Solo las piedras volcánicas mostraron actividad catalítica y ésta, en comparación con la del catalizador de alginato fue baja.
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Baldoni-Andrey, Patrick. "Etude comparative de l'oxydation de composés aliphatiques en milieu aqueux par les procédés Fenton et photo-Fenton." Poitiers, 2001. http://www.theses.fr/2001POIT2336.
Full textAbstract:
Cette étude a pour objectif d'étudier et de comparer les performances des procédés d'oxydation radicalaire par le réactif de Fenton (FeII/H2O2), par les procédés photo-Fenton (FeII/H2O2/UV) et H2O2/UV pour l'oxydation de composés organiques et d'effluents industriels. L'oxydation des acides acétique et chloroacétique par les trois procédés d'oxydation étudiés conduit, en présence d'oxygène dissous, à une minéralisation très avancée du carbone organique (COT) ainsi qu'à une minéralisation quasi-totale du chlore organique. En absence d'oxygène dissous, l'oxydation radicalaire de l'acide chloroacétique conduit à la formation de sous produits organochlorés. La minéralisation du COT par le réactif de Fenton nécessite des doses beaucoup plus importantes de réactifs (FeII et H2O2) que par les procédés FeII/H2O2/UV et H2O2/UV. Pour l'oxydation des effluents industriels testés, le procédé photo-Fenton est plus performant que le procédé H2O2/UV et nécessite des doses moins élevées de réactifs que le système FeII/H2O2<br>The objective of this work was to study and compare the performances of advanced oxidation processes, namely Fenton reagent (FeII/H2O2) and photo-Fenton (FeII/H2O2/UV) and H2O2/UV processes for the oxidation of aliphatic compounds and industrial wastewaters. The oxidation of acetic and chloroacetic acids by the three experimented processes leads, in the presence of dissolved oxygen, to a fast mineralization of the organic carbon (TOC) and simultaneously to the mineralization of almost all the organic chlorine. In the absence of dissolved oxygen, the OH radical oxidation leads to the formation of orgnochlorinated by-products. The mineralization of TOC by the Fenton reagent requires much higher FeII and H2O2 doses than FeII/H2O2/UV and H2O2/UV processes. Concerning the oxidation of the industrial wastewater samples the photo-Fenton process is more efficient than H2O2/UV system, and requires much lower doses of reagents than the Fenton process
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Laugel, Caroline. "Oxydation catalytique de la biomasse : oxydation photo-fenton de l’amidon et oxydation de l’hydroxymethylfurfural." Thesis, Reims, 2013. http://www.theses.fr/2013REIMS048.
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Des solutions d'acides carboxyliques contenant principalement de l'acide formique sont obtenues par oxydation photo-Fenton des polysaccharides. Une irradiation dans le visible de 60 W sous des conditions douces suffit à fournir des résultats reproductibles. Les produits d'oxydation issus d'amidon de pomme de terre et d'amidon de blé ont montré des capacités de complexation comparables aux solutions commerciales d'acide gluconique et glucuronique.Un système d'oxydation innovant, comprenant des sels d'halogénures et du DMSO, convertit quantitativement le HMF en DFF. Cette méthode permet aussi la transformation one-pot du fructose en DFF avec de bons rendements. Selon l'étude mécanistique, le bromo-HMF serait un intermédiaire réactionnel<br>Solutions of carboxylic acids, containing mainly formic acid, are produced under photo-Fenton conditions. Visible irradiation with a 60 W spot is sufficient to provide reproducible results under mild conditions. The oxidation products of potato starch and wheat starch have shown Ca sequestering properties similar to those of gluconic and glucuronic acids.Using halide salts and DMSO, an innovating method has been elaborated for the selective oxidation of HMF to DFF with quantitative yields. The one-pot transformation of fructose to DFF occurs with fair yields. Based on the mechanistic study, Br-HMF would be the reaction intermediate
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Güere, Carlos Dante Gamarra. "Estudo da degradação do metil parabeno utilizando processos Fenton, foto-Fenton e eletro-Fenton." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-21112014-160153/.
Full textAbstract:
Os disruptores endócrinos são frequentemente relatados na literatura como contaminantes de ambientes aquáticos. Por isso, os processos oxidativos avançados (POAs) têm sido estudados como alternativa para o tratamento em meio aquoso. Os POAs consistem na oxidação de compostos orgânicos por radicais hidroxilas com alto poder oxidante. Diante desses aspectos, o presente trabalho tem como principal objetivo o estudo da degradação do metil parabeno (MeP) por processos Fenton, utilizando planejamento experimental e a análise dos modelos matemáticos, possibilitando a avaliação da influência das variáveis e determinando as melhores condições. As degradações de 300 mL de 100 mg L-1 de MeP com o processo Fenton foram realizadas em um reator de vidro onde as concentrações ótimas foram: 16 mg L-1 de Fe2+, 62 mg L-1 de H2O2, pH = 3, agitação constante e 30°C chegando a 100% de degradação em 20 minutos. Para o foto-Fenton, as degradações foram de 500 mL de 100 mg L-1 de MeP em um reator com lâmpada de mercúrio de 4 W , utilizando-se uma concentração de 4 mg L-1 de Fe2+ e 52 mg L-1 de H2O2, pH = 3, 30°C e agitação constante chegando a 100% de degradação em 16 minutos. Finalmente a degradação de 300 mL de 100 mg L-1 de MeP por eletro- Fenton foi realizada em um reator, com 4 mg L-1 de Fe2+, com densidade de corrente (j = 25 mA cm-2) para a produção de H2O2 com eletrodos ADE(cátodo), platina(ânodo), 0,05 mol L-1 de Na2SO4 como eletrólito suporte, pH = 3, sob agitação constante e 30°C chegando a 100% de degradação em 11 minutos. A eficiência da degradação de MeP foi monitorada por espectroscopia UV-VIS e cromatografia liquida de alta eficiência (CLAE) e, a mineralização, pelo monitoramento do carbono orgânico total (COT).<br>Endocrine disruptors are frequently reported in the literature as contaminants of aquatic environments. Therefore, the advanced oxidation processes (AOPs) have been studied as an alternative to aqueous media treatments. AOPs involve the oxidation of organic compounds by hydroxyl radicals with high oxidation power. Considering these aspects, the aim of the present work is to study the methyl paraben (MeP) degradation by Fenton processes using experimental design and analysis of mathematical models, allowing the evaluation of the influence of variables and determining the best conditions. The degradation of 300 mL of 100 mg L-1 of MeP with Fenton process was performed in a glass reactor where the optimal concentrations were 16 mg L-1 of Fe2+, 62 mg L-1 of H2O2, pH = 3, constant stirring and T = 30°C, reaching 100 % degradation in 20 minutes . For the photo-Fenton degradations were 500 mL of 100 mg L-1 of MeP in a reactor with a mercury lamp with 4 W, using concentration of 4 mg L-1 of Fe2+, 52 mg L-1 of H2O2, pH = 3 , T = 30°C and constant stirring, reaching 100 % biodegradation in 16 minutes. Finally, the degradation of 300 mL of 100 mg L-1 of MeP by electro-Fenton was carried out in a reactor with 4 mg L-1 of Fe2+ with current density (j = 25 mA cm-2) for the production of H2O2 with ADE electrodes (cathode), platinum (anode), 0.05 mol L-1 Na2SO4 as supporting electrolyte, pH = 3, T = 30°C and constant stirring, to reaching 100 % degradation in 11 minutes. The degradation efficiency of MeP was monitored by UV- VIS spectroscopy and liquid chromatography (HPLC) and mineralization, by monitoring the total organic carbon (TOC).
Book chapters on the topic "Photo-Fenton"
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Zhang, Jinlong, Baozhu Tian, Lingzhi Wang, Mingyang Xing, and Juying Lei. "Photo-Fenton Reaction." In Lecture Notes in Chemistry. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2113-9_11.
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Zhang, Jinlong, Baozhu Tian, Lingzhi Wang, Mingyang Xing, and Juying Lei. "Heterogeneous Photo-Fenton Technology." In Lecture Notes in Chemistry. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2113-9_10.
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Lee, Changha, Jiwon Seo, and Anh Le-Tuan Pham. "The Photo-Fenton System." In Springer Handbook of Inorganic Photochemistry. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-63713-2_59.
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Deb, Anjan, Jannatul Rumky, and Mika Sillanpää. "Fenton, Photo-Fenton, and Electro-Fenton Systems for Micropollutant Treatment Processes." In Advanced Oxidation Processes for Micropollutant Remediation. CRC Press, 2023. http://dx.doi.org/10.1201/9781003247913-8.
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Zhang, Jinlong, Baozhu Tian, Lingzhi Wang, Mingyang Xing, and Juying Lei. "MoS2 Applications in Photo-Fenton Technology." In Lecture Notes in Chemistry. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2113-9_15.
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Polo-López, María Inmaculada, Samira Nahim-Granados, and Pilar Fernández-Ibáñez. "Homogeneous Fenton and Photo-Fenton Disinfection of Surface and Groundwater." In The Handbook of Environmental Chemistry. Springer International Publishing, 2018. http://dx.doi.org/10.1007/698_2017_129.
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Gupta, Meghavi, Noopur Ameta, Surbhi Benjamin, and P. B. Punjabi. "Photo-Fenton Reactions: A Green Chemical Route." In Green Chemistry, 2nd edition, 2nd ed. Apple Academic Press, 2024. http://dx.doi.org/10.1201/9781003431473-9.
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Alfano, Orlando M., Enrique D. Albizzati, and Leandro O. Conte. "Modelling of Photo-Fenton Solar Reactors for Environmental Applications." In Environmental Photochemistry Part III. Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/698_2013_246.
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Gomis, J., M. Mora, R. Vicente, R. Vercher, A. M. Amat, and A. Arques. "SBO in Water Detoxification: Photo-Fenton Processes at Mild Conditions." In SpringerBriefs in Molecular Science. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14744-4_3.
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Carabineiro, S. A. C., A. M. T. Silva, C. G. Silva, et al. "Iron Oxide Materials for Photo-Fenton Conversion of Water Pollutants." In Application of Nanotechnology in Water Research. John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118939314.ch16.
Full textConference papers on the topic "Photo-Fenton"
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"Oxidation of Organic Matter in Wastewater with Fenton, Photo-Fenton, Photo-Hydrogen Peroxide and Hydrogen Peroxide." In International Conference on Biological, Civil and Environmental Engineering. International Institute of Chemical, Biological & Environmental Engineering, 2014. http://dx.doi.org/10.15242/iicbe.c0314014.
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CHENG, Peng, Marcello Brigante, Mohamed Sarakha, and Gilles Mailhot. "Kinetic analysis of the photo-Fenton/Fenton-like reaction by Ferrozine." In Goldschmidt2023. European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.20730.
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Stefanescu, Mihai, Costel Bumbac, and Ionut Cristea. "ADVANCED REMOVAL OF GAMMA HCH FROM WATER BY ULTRASONICATION, FENTON AND PHOTO FENTON ULTRASONICATION." In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023v/3.2/s12.02.
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Historical pollution with hexachlorocyclohexane (HCH) isomers of soil and groundwater unfortunately is an unsolved problem, especially in some countries where Lindane is still produced, as also in Europe in the surrounding areas of former production sites or landfilling sites usually due to inadequate long-term storage, treatment or recovery of these wastes. HCH removal technologies are usually dedicated to soil remediation, leachate treatment, water and wastewater treatment. This paper presents the research efforts to develop a treatment technology for gamma HCH removal from water matrices by advanced oxidation processes (AOPs) based on ultrasonication, Fenton and photo Fenton oxidation. Five treatment systems were assessed comparatively: direct ultrasonication, oxidation with hydrogen peroxide, ultrasonication with hydrogen peroxide, Fenton ultrasonication and Fenton ultrasonication followed by photo Fenton oxidation. The energy (25-800 kJ) and amplitude of ultrasonic field, initial concentration of HCH (10 - 89 ?g/L), hydrogen peroxide (1 - 4000 x stoichiometric dose), iron (Fe II) doses (1-15 mg/L) and UV irradiation time (30-60 min.) were the main experimental parameters evaluated. The ultrasonic frequency was constant - 20 kHz in all experiments. Best treatment performance of 99.9% HCH removal efficiency was achieved after application of a treatment train combining Fenton ultrasonication followed by Fenton UV photolysis at the main experimental parameters of: 200 kJ ultrasonic energy, 1000 x s peroxide dose, 5 mg Fe(II)/L and 30 minutes of UV irradiation.
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Çokay, Ebru, and Serkan Eker. "Pesticide Industry Wastewater Treatment with Photo-Fenton Process." In Innovations-Sustainability-Modernity-Openness Conference. MDPI, 2022. http://dx.doi.org/10.3390/environsciproc2022018015.
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Jafer, A. S., R. Al-Khateeb, B. Alobaid, A. Atiyah, and A. A. Hassan. "Copper removal from produced water by photo Fenton oxidation." In SECOND INTERNATIONAL CONFERENCE ON INNOVATIONS IN SOFTWARE ARCHITECTURE AND COMPUTATIONAL SYSTEMS (ISACS 2022). AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0165033.
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Li Meng-yao, Jiao Jin-liang, Wen Hai-hua, and Wen Zhi-zhong. "Study on oxidation of sodium chlorophenols by heterogeneous photo-fenton." In 2011 International Symposium on Water Resource and Environmental Protection (ISWREP). IEEE, 2011. http://dx.doi.org/10.1109/iswrep.2011.5893499.
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Nakagawa, Hiroyuki, and Emi Yamaguchi. "Mineralization of Phenol in Water Utilizing Photo-assisted Fenton Reaction." In 14th Asia Pacific Confederation of Chemical Engineering Congress. Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-1445-1_274.
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Xiaolian Hu and Xifeng Wang. "Photo-fenton treatment of dimethoate using TiO2 film and UV radiation." In 2010 2nd International Conference on Chemical, Biological and Environmental Engineering (ICBEE 2010). IEEE, 2010. http://dx.doi.org/10.1109/icbee.2010.5649070.
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Jabbar, Huda Radhi, and Khalid M. Mousa Al-zobai. "Remediation of wastewater contaminated by tetracycline using photo Fenton-Advanced oxidation." In 3RD INTERNATIONAL CONFERENCE ON ENERGY AND POWER, ICEP2021. AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0109724.
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Ribeiro, João Peres, Catarina Costa Marques, and Maria Isabel Nunes. "Assessment of Catalytic Performance of Fe2+ , Fe3+ and Fe2+:Cu2+ In Fenton and Photo-Fenton Treatment of Pulp Bleaching Wastewaterr." In The 7th World Congress on New Technologies. Avestia Publishing, 2021. http://dx.doi.org/10.11159/icepr21.117.
Full textReports on the topic "Photo-Fenton"
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Asenath-Smith, Emily, Emma Ambrogi, Eftihia Barnes, and Jonathon Brame. CuO enhances the photocatalytic activity of Fe₂O₃ through synergistic reactive oxygen species interactions. Engineer Research and Development Center (U.S.), 2021. http://dx.doi.org/10.21079/11681/42131.
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Iron oxide (α-Fe₂O₃, hematite) colloids were synthesized under hydrothermal conditions and investigated as catalysts for the photodegradation of an organic dye under broad-spectrum illumination. To enhance photocatalytic performance, Fe₂O₃ was combined with other transition-metal oxide (TMO) colloids (e.g., CuO and ZnO), which are sensitive to different regions of the solar spectrum (far visible and ultraviolet, respectively), using a ternary blending approach for compositional mixtures. For a variety of ZnO/Fe₂O₃/CuO mole ratios, the pseudo-first-order rate constant for methyl orange degradation was at least double the sum of the individual Fe₂O₃ and CuO rate constants, indicating there is an underlying synergy governing the photocatalysis reaction with these combinations of TMOs. A full compositional study was carried out to map the interactions between the three TMOs. Additional experiments probed the identity and role of reactive oxygen species and elucidated the mechanism by which CuO enhanced Fe₂O₃ photodegradation while ZnO did not. The increased photocatalytic performance of Fe2O3 in the presence of CuO was associated with hydroxyl radical ROS, consistent with heterogeneous photo-Fenton mechanisms, which are not accessible by ZnO. These results imply that low-cost photocatalytic materials can be engineered for high performance under solar illumination by selective pairing of TMOs with compatible ROS.