[pt] O presente trabalho avalia a utilização de dois diferentes tipos de POA, Fenton-Zero - processo Fenton utilizando ferro zero valente: Fe0/H2O2 - e UV/H2O2 para o tratamento de efluente de indústria de celulose tratado biologicamente. Os parâmetros observados foram DBO, DQO, COT, cor e ABS280nm (medida de compostos ligninícos). Os experimentos foram conduzidos em batelada, em escala de laboratório e utilizando efluente real de indústria de celulose tratado biologicamente. Para os testes com o processo Fenton Zero foram realizados experimentos de acordo com um planejamento fatorial 2 elevado a 3, investigando a influência das variáveis pH, dosagem de peróxido de hidrogênio e massa de ferro zero valente fornecida por volume de solução. Como fonte de ferro foi utilizada lã de aço comercial nas concentrações de 5,5 g/L, 6,5 g/L e 7,5 g/L. As concentrações iniciais de peróxido de hidrogênio estudadas foram de 456,9 mg/L, 913,7 mg/L e 1370,6 mg/L e os valores de pH variaram entre 5.5, 6.5 e 7.5. Foram obtidas médias de remoção de 57,1 por cento de DQO, 67,2 por cento de DBO, 90,5 por cento de Cor, 83,4 por cento de compostos lignínicos e 54 por cento de COT, além de 9,52 mg/L de DBO final e 60,1 mg/L de DQO final. Já os testes com o sistema UV/H2O2 foram conduzidos com o único objetivo de polimento do efluente para reuso pelo processo. Desta maneira, o pH utilizado foi o natural do efluente (7,5) e três doses de H2O2 foram aplicadas, 4,0 g/L, 5,0 g/L e 6,0 g/L estando estas em excesso. / [en] The present work evaluates the use of two different types of AOP: the Zero-Fenton - process using zero valent iron - and UV/H2O2 for the treatment of pulp mill wastewater biologically treated. The observed parameters were BOD, COD, TOC, color and ABS280nm (measure of lignin compounds). The experiments were conducted in batch, lab scale and with real wastewater from biological treatment of a cellulose plant in Brazil. For the Fenton process, experiments were carried out according to a factorial design 23 investigating the influence of the variables pH, hydrogen peroxide dosage and zero-valent iron mass supplied by solution volume. As iron source, commercial steel wool was used in the concentrations of 5.5 g / L, 6.5 g / L and 7.5 g / L. The concentrations of hydrogen peroxide studied were 456.9 mg / L, 913.7 mg / L and 1370.6 mg / L and pH values ranged from 5.5, 6.5 and 7.5. The average removal rate was 57.1 per cent COD, 67.2 per cent COD, 90.5 per cent Color, 83.4 per cent lignin compounds and 54 per cent TOC. Also 9,52 mg/L of final BOD and 60,1 mg/L of final COD. The trials with the UV/H2O2 system, on the other hand, were conducted with the sole objective of polishing the effluent for reuse in the process. The pH used was the effluent s natural (7.5) and three excess doses of H2O2 were applied.

Persistent organic pollutants (POPs) are organic compounds of anthropogenic origin that have been linked to the development of cancer, neurobehavioural impairment, and immune system biochemical alterations. These chemicals have various industrial applications as well as acting as pesticides. Dioxins and furans are some of these compounds that are unintentionally produced in combustion and industrial processes. By definition these compounds have 4 common qualities: they are highly toxic, they are resistant to environmental degradation, they are introduced into the air and water where they travel long distances, and they accumulate in fatty tissues. Photochemical degradation is a method that has been extensively researched in the last few decades. In the aqueous phase it has already been shown to be able to degrade a number of refractory organics, such as dioxins and furans. The ultimate products of this process tend to be carbon dioxide, water, and mineral anions. Air phase work has been also gaining attention in recent decades as a possible alternative to incineration methods in air pollution control. The advantages of photochemical degradation processes are that they can be initiated at low temperatures, are relatively low cost compared to incineration processes, environmentally benign, and have the potential for quick and complete degradation of organic compounds. The main aim of the research is to investigate the photochemical degradation potential of PCDD/ PCDFs in gaseous air streams as a potential air pollution control technology. In order to do this, the photodegradation reaction kinetics were determined for chlorobenzene as a suitable surrogate for PCDD/PCDFs. Three different photodegradation schemes were employed: direct photolysis, UV/O3, and UV/H2O2. In addition, ozonolysis reaction rates were also determined to evaluate the effects of on the overall photodegradation rates for the UV/O3 process. Factors such as humidity levels and temperature were investigated to determine their effects on degradation rates. Temperature and humidity were not greatly influential on the degradation rates of direct photolysis. The degradation rate of chlorobenzene at a temperature of 100°C and high humidity was noticeably reduced, but unchanged at the 10% RH and 60% RH levels for all temperatures. Ozonolysis of chlorobenzene was negligible at 30°C for all humidity levels. Ozonolysis reactions at the 60°C and 100°C levels were higher than direct photolysis rates and in the 100°C case exceeded the UV/O3 degradation rates. Ozone coupled with UV experiments proved to be the most destructive at the low temperature of 30°C and molar ratio of 10:1 ozone to chlorobenzene. There was a clear and positive relationship between the amount of ozone present in the reactor and the degradation rate. At lower ozone to chlorobenzene molar ratios the degradation rates were not much higher than those for direct photolysis of ozone. The 5:1 molar ratio saw a significant increase in degradation rates over the photolysis rates. The fastest degradation rate was achieved for the 10:1 molar ratio and high humidity, which was over 10 times the rate of direct photolysis. In addition, humidity had a noticeably significant positive effect in these reactions. The effect of temperature on the UV/ozone reaction scheme was determined for the 5:1 ozone to chlorobenzene ratio. Temperature had an interesting effect on the degradation rates at higher temperatures. As the reactor temperature increased, the degradation rates from ozonolysis and UV/O3 began to converge at 60°C, ultimately leading to the ozonolysis reaction being faster than the UV/O3. Exploratory experiments for the H2O2 scheme were performed. H2O2 had a positive influence on the degradation rate of chlorobenzene and was about 26% higher than the direct photolysis rates. However for similar conditions, the UV/O3 process had higher degradation rates as was expected from the difference in absorption values between ozone and hydrogen peroxide.

The ability of six types of granular activated carbon (GAC) to quench H2O2 was evaluated by bench-scale H2O2 decomposition kinetics tests and pilot-scale H2O2 breakthrough tests. Bench-scale studies showed that carbon ageing significantly reduced the performance of H2O2 quenching by the GAC, but that the greatest impacts occurred within the first 25 000 bed volumes of water treated, with performance tending to stabilize afterwards. Pilot-scale studies suggested that both H2O2 exposure and exposure to natural organic matter were important factors in GAC ageing, with exposure to oxygen also suspected of being important. A continuously stirred tank reactor (CSTR)-in-series model was proposed for the prediction of H2O2 breakthrough in a GAC column.

The ability of six types of granular activated carbon (GAC) to quench H2O2 was evaluated by bench-scale H2O2 decomposition kinetics tests and pilot-scale H2O2 breakthrough tests. Bench-scale studies showed that carbon ageing significantly reduced the performance of H2O2 quenching by the GAC, but that the greatest impacts occurred within the first 25 000 bed volumes of water treated, with performance tending to stabilize afterwards. Pilot-scale studies suggested that both H2O2 exposure and exposure to natural organic matter were important factors in GAC ageing, with exposure to oxygen also suspected of being important. A continuously stirred tank reactor (CSTR)-in-series model was proposed for the prediction of H2O2 breakthrough in a GAC column.

The effects of UV pretreatment on alkaline bleaching (EOP) wastewater from a kraft pulp and paper mill were investigated prior to anaerobic digestion (AD) in an upflow anaerobic sludge blanket (UASB) reactor. The aim was to enhance the methane production, increase the reduction of total organic carbon (TOC) and determine the best UV exposure time. The exposure time of 2.6 minutes partially degraded the organic material in the EOP wastewater since it generated higher biogas and methane production than the reference period, while it also increased the reductions of solved chemical oxygen demand (CODsol) and TOCsol. The exposure time of 16 minutes, on the other hand, did not show any significant improvement regarding increased biogas and methane production nor did it increase the reduction of CODsol. However, it did increase the reduction of TOCsol, but not to the same extent as the exposure time of 2.6 minutes. The presence of unwanted microbial growth in the system during the experiment might have affected the effectiveness of the UV pretreatment more during the exposure time of 16 minutes as the amount of growth was more substantial during this period of time. Furthermore, no optimal exposure time could be determined due to lack of time.

Persistent organic pollutants (POPs) are organic compounds of anthropogenic origin that have been linked to the development of cancer, neurobehavioural impairment, and immune system biochemical alterations. These chemicals have various industrial applications as well as acting as pesticides. Dioxins and furans are some of these compounds that are unintentionally produced in combustion and industrial processes. By definition these compounds have 4 common qualities: they are highly toxic, they are resistant to environmental degradation, they are introduced into the air and water where they travel long distances, and they accumulate in fatty tissues. Photochemical degradation is a method that has been extensively researched in the last few decades. In the aqueous phase it has already been shown to be able to degrade a number of refractory organics, such as dioxins and furans. The ultimate products of this process tend to be carbon dioxide, water, and mineral anions. Air phase work has been also gaining attention in recent decades as a possible alternative to incineration methods in air pollution control. The advantages of photochemical degradation processes are that they can be initiated at low temperatures, are relatively low cost compared to incineration processes, environmentally benign, and have the potential for quick and complete degradation of organic compounds. The main aim of the research is to investigate the photochemical degradation potential of PCDD/ PCDFs in gaseous air streams as a potential air pollution control technology. In order to do this, the photodegradation reaction kinetics were determined for chlorobenzene as a suitable surrogate for PCDD/PCDFs. Three different photodegradation schemes were employed: direct photolysis, UV/O3, and UV/H2O2. In addition, ozonolysis reaction rates were also determined to evaluate the effects of on the overall photodegradation rates for the UV/O3 process. Factors such as humidity levels and temperature were investigated to determine their effects on degradation rates. Temperature and humidity were not greatly influential on the degradation rates of direct photolysis. The degradation rate of chlorobenzene at a temperature of 100°C and high humidity was noticeably reduced, but unchanged at the 10% RH and 60% RH levels for all temperatures. Ozonolysis of chlorobenzene was negligible at 30°C for all humidity levels. Ozonolysis reactions at the 60°C and 100°C levels were higher than direct photolysis rates and in the 100°C case exceeded the UV/O3 degradation rates. Ozone coupled with UV experiments proved to be the most destructive at the low temperature of 30°C and molar ratio of 10:1 ozone to chlorobenzene. There was a clear and positive relationship between the amount of ozone present in the reactor and the degradation rate. At lower ozone to chlorobenzene molar ratios the degradation rates were not much higher than those for direct photolysis of ozone. The 5:1 molar ratio saw a significant increase in degradation rates over the photolysis rates. The fastest degradation rate was achieved for the 10:1 molar ratio and high humidity, which was over 10 times the rate of direct photolysis. In addition, humidity had a noticeably significant positive effect in these reactions. The effect of temperature on the UV/ozone reaction scheme was determined for the 5:1 ozone to chlorobenzene ratio. Temperature had an interesting effect on the degradation rates at higher temperatures. As the reactor temperature increased, the degradation rates from ozonolysis and UV/O3 began to converge at 60°C, ultimately leading to the ozonolysis reaction being faster than the UV/O3. Exploratory experiments for the H2O2 scheme were performed. H2O2 had a positive influence on the degradation rate of chlorobenzene and was about 26% higher than the direct photolysis rates. However for similar conditions, the UV/O3 process had higher degradation rates as was expected from the difference in absorption values between ozone and hydrogen peroxide.

Dans un contexte de raréfaction de la ressource en eau, le traitement des eaux usées peut permettre de constituer des réserves d’eau durables et valorisables pour des usages variés tels que l’irrigation des cultures, la recharge de nappe phréatique ou encore une utilisation directe par les industries grandes consommatrices d’eau (cimenterie, aciéries…). Ainsi, la nécessité d’améliorer le traitement des eaux usées en sortie de STEU devient primordial afin d’assurer une qualité chimique et microbiologique de l’eau compatible avec sa réutilisation. Le traitement des micropolluants constitue notamment un nouveau défi pour les STEU. Si des projets de recyclage des eaux usées émergent pour les grandes STEU, le potentiel des petites ou moyennes STEU, qui constituent près de 90% des installations en France, reste inexploité à l’heure actuelle. Pour y remédier, les procédés d’oxydation avancée, notamment ceux basés sur l’UV, se présentent comme des solutions de traitement prometteuses. L’objectif de cette étude est de démontrer que la technologie UV/H2O2 est efficace et économiquement réaliste pour la désinfection et l’élimination des micropolluants organiques dans ces petites et moyennes STEU. Dans une première phase, un pilote de laboratoire UV/H2O2 a été évalué en conditions réelles (débit, matrice) sur des modèles bactériens et sur des micropolluants estrogéniques (E1, E2 et EE2) dans les eaux usées traitées d’une STEU. L’efficacité du traitement est comparée à celle de la photolyse seule. Il a été montré que le traitement UV/H2O2 permet une amélioration de la désinfection en assurant une destruction des bactéries contrairement à la photolyse seule qui ne fait qu’inactiver les micro-organismes. D’autre part, les doses UV (plus petit 600 mJ/cm²) et les concentrations en H2O2 étudiées (30-50 mg/L d’H2O2) permettent d’abattre plus de 80% de l’ensemble des micropolluants ciblés et de l’activité biologique (estrogénicité) associée, sans former de sous-produits estrogéniques ou toxiques au regard des tests d’activité employés dans l’étude (YES et Vibrio Fisheri). Parallèlement, il a été montré que le procédé UV/H2O2 est également efficace pour éliminer plus de 70% des produits pharmaceutiques (diclofénac, ibuprofène et naproxène) à 1000 mJ/cm². Sur la base des paramètres de traitement établis en pilote de laboratoire, un prototype a été dimensionné pour la STEU de Vercia (filtre planté de roseaux, 1100 EH, Jura). Les conditions de traitement mises en œuvre (dose UV plus pertit 1000 mJ/cm², [H2O2] = 15 mg/L) ont permis d’obtenir une eau de très haute qualité bactériologique et des abattements des micropolluants suivis supérieurs à 90%. Cette expérimentation à échelle réelle a permis d’estimer le coût global de cette technologie à environ 0,28 €/m³. L’ensemble de ce travail de recherche conclue à l’efficacité et au fort potentiel de la technologie UV/H2O2 pour le recyclage des eaux usées traitées des petites et moyennes STEU. / Water scarcity is a growing concern worldwide. In this context, treated wastewater is seen as a sustainable water resource which could be used for different purposes such as irrigation, groundwater recharge or industrial activities. Reclaimed water is an environmentally and economically solution, still poorly developed in France. However, an increasing demand is expected in the coming years. Therefore, treatment enhancement in wastewater treatment plant could be necessary in order to meet chemical and biological water quality requirements which will depend on the final use of the treated water. The treatment of emerging micropollutants is one of the new challenge WTP will have to cope with. Enhanced treatment processes (ozonation, activated carbon, membrane filtration) have already been set up in large WTP but small and medium WTP, representing around 90% of the French WTP, are still lacking of affordable treatment solutions. However, UV based advanced oxidation process (AOP) could be a promising technology in order to produce a water of high quality. The aim of this study is to demonstrate that UV/H2O2 process is technically and economically efficient for the disinfection and the removal of micropollutants in small and medium WTP. First of all, a UV/H2O2 pilot at a laboratory scale was assessed on bacterial models as well as estrogenic micropollutants (E1, E2 and EE2) in treated wastewater. Treatment efficiency was compared to UV photolysis. It was shown that UV/H2O2 treatment increased the disinfection process by destroying the cellular membrane integrity whereas the UV photolysis could only inactive the bacteria. Moreover, when combining UV (plus petit 600 mJ/cm²) and H2O2 (30-50 mg/L), above 80% of the estrogenic compounds and the associated estrogenic activity could be removed. No high estrogenic or toxic by-products were detected by the two bioassays used in this study (YES and vibrio fisheri). The UV/H2O2 process could also degrade pharmaceuticals such as diclofenac, ibuprofen and naproxen (>70 % at 1000 mJ/cm²). In a second part, a full scale pilot was designed based on the previous results and set up in a WTP in Vercia (Jura). The treatment (UV fluence ≈ 1000 mJ/cm², [H2O2] = 15 mg/L) allowed to obtain a water of a very high bacteriological and chemical quality. The global cost of the process was estimated at around 0.28 €/m³. This study demonstrates the efficiency of the UV/H2O2 process in a small WTP and its high potential for reclaimed water production

A racionalização dos recursos hídricos tem sido uma das metas das indústrias em vários setores. Tais metas exigem inovações tecnológicas tanto para novos processos produtivos quanto para novas técnicas de tratamento e reutilização de água na cadeia de produção. Os custos elevados de água industrial no Brasil, particularmente nas regiões metropolitanas, têm estimulado as indústrias nacionais a avaliar as possibilidades de reúso. O objetivo deste trabalho é a aplicação do tratamento de águas de processo contendo polipropileno utilizando radiação ultravioleta e peróxido de hidrogênio, isto é, o sistema UV/H2O2, visando adequá-las para reúso no próprio processo, reduzindo a necessidade de captação de água pré-tratada e de descarte de efluente. A primeira parte do estudo consistiu na realização de experimentos em um sistema fotoquímico de batelada, empregando quatro diferentes correntes efluentes de processo, para a avaliação da viabilidade técnico-econômica do tratamento fotoquímico, bem como para a obtenção de dados referentes à cinética das reações fotoquímicas. Com base nas informações obtidas, na segunda parte do estudo foram realizados experimentos em um sistema fotoquímico contínuo, a fim de obter dados para o aumento de escala para aplicação industrial do processo de tratamento contínuo. Os resultados experimentais indicaram a viabilidade técnica de aplicação do sistema UV/H2O2 utilizando fonte de luz artificial para todas as correntes de processo estudadas, tendo sido alcançados níveis de remoção de matéria orgânica acima de 90%. No entanto, sob o ponto de vista econômico, apenas as correntes com baixo teor de carbono orgânico total dissolvido (COT), entre 6 e 12 mgC L-1, mostraram-se adequadas ao reúso, após o tratamento. / Rationalization of water use has been one of the goals in many industrial activities, and, in particular, in the petrochemical industry. Such goals demand technological innovations in the productive processes and in techniques for treatment and reuse of water in the production chain. The high costs of industrial water, particularly in some metropolitan regions, have stimulated the industries to evaluate the possibilities of water reuse. The objective of this work is to evaluate the feasibility of the UV/H2O2 photochemical process applied to the treatment of process waste water containing polypropylene, aiming at the reuse of the waste water in the as process water in the industrial complex, thus reducing the need for tap water supply and waste water generation rate. The first part of this study consisted of laboratory-scale experiments in a batch photochemical reactor with four different waste water streams to perform the technical and economical feasibility of the photochemical treatment, as well to obtain data on the degradation rate. Based on the results of the first part, the second part of this study consisted of experiments in a continuous photochemical reactor, aimed at obtaining experimental data for reactor scale-up. Experimental results indicate that the UV/H2O2 photodegradation process is able to remove more than 90% of the organic compounds contained in the waste water. However, only waste waters containing relatively low contaminant levels (between 6 and 12 mgC L-1) can be treated at economically favourable costs.

A racionalização dos recursos hídricos tem sido uma das metas das indústrias em vários setores. Tais metas exigem inovações tecnológicas tanto para novos processos produtivos quanto para novas técnicas de tratamento e reutilização de água na cadeia de produção. Os custos elevados de água industrial no Brasil, particularmente nas regiões metropolitanas, têm estimulado as indústrias nacionais a avaliar as possibilidades de reúso. O objetivo deste trabalho é a aplicação do tratamento de águas de processo contendo polipropileno utilizando radiação ultravioleta e peróxido de hidrogênio, isto é, o sistema UV/H2O2, visando adequá-las para reúso no próprio processo, reduzindo a necessidade de captação de água pré-tratada e de descarte de efluente. A primeira parte do estudo consistiu na realização de experimentos em um sistema fotoquímico de batelada, empregando quatro diferentes correntes efluentes de processo, para a avaliação da viabilidade técnico-econômica do tratamento fotoquímico, bem como para a obtenção de dados referentes à cinética das reações fotoquímicas. Com base nas informações obtidas, na segunda parte do estudo foram realizados experimentos em um sistema fotoquímico contínuo, a fim de obter dados para o aumento de escala para aplicação industrial do processo de tratamento contínuo. Os resultados experimentais indicaram a viabilidade técnica de aplicação do sistema UV/H2O2 utilizando fonte de luz artificial para todas as correntes de processo estudadas, tendo sido alcançados níveis de remoção de matéria orgânica acima de 90%. No entanto, sob o ponto de vista econômico, apenas as correntes com baixo teor de carbono orgânico total dissolvido (COT), entre 6 e 12 mgC L-1, mostraram-se adequadas ao reúso, após o tratamento. / Rationalization of water use has been one of the goals in many industrial activities, and, in particular, in the petrochemical industry. Such goals demand technological innovations in the productive processes and in techniques for treatment and reuse of water in the production chain. The high costs of industrial water, particularly in some metropolitan regions, have stimulated the industries to evaluate the possibilities of water reuse. The objective of this work is to evaluate the feasibility of the UV/H2O2 photochemical process applied to the treatment of process waste water containing polypropylene, aiming at the reuse of the waste water in the as process water in the industrial complex, thus reducing the need for tap water supply and waste water generation rate. The first part of this study consisted of laboratory-scale experiments in a batch photochemical reactor with four different waste water streams to perform the technical and economical feasibility of the photochemical treatment, as well to obtain data on the degradation rate. Based on the results of the first part, the second part of this study consisted of experiments in a continuous photochemical reactor, aimed at obtaining experimental data for reactor scale-up. Experimental results indicate that the UV/H2O2 photodegradation process is able to remove more than 90% of the organic compounds contained in the waste water. However, only waste waters containing relatively low contaminant levels (between 6 and 12 mgC L-1) can be treated at economically favourable costs.

No description available.