Degradação fotoquímica de hidrocarbonetos da gasolina em efluentes aquosos

Photo-oxidation processes of toxic organic compounds have been widely studied. This work seeks the application of the photo-Fenton process for the degradation of hydrocarbons in water. The gasoline found in the refinery, without additives and alcohol, was used as the model pollutant. The effects of the concentration of the following substances have been properly evaluated: hydrogen peroxide (100-200 mM), iron ions (0.5-1 mM) and sodium chloride (200 2000 ppm). The experiments were accomplished in reactor with UV lamp and in a falling film solar reactor. The photo-oxidation process was monitored by measurements of the absorption spectra, total organic carbon (TOC) and chemical oxygen demand (COD). Experimental results demonstrated that the photo-Fenton process is feasible for the treatment of wastewaters containing aliphatic hydrocarbons, inclusive in the presence of salts. These conditions are similar to the water produced by the petroleum fields, generated in the extraction and production of petroleum. A neural network model of process correlated well the observed data for the photooxidation process of hydrocarbons

Análise dos Processos de Flotação e Oxidação Avançada para o Tratamento de Efluente Modelo da Indústria do Petróleo

The generation of wastes in most industrial process is inevitable. In the petroleum industry, one of the greatest problems for the environment is the huge amount of produced water generated in the oil fields. This wastewater is a complex mixture and present great amounts. These effluents can be hazardous to the environmental without adequate treatment. This research is focused in the analysis of the efficiencies of the flotation and photo-oxidation processes to remove and decompose the organic compounds present in the produced water. A series of surfactants derivated from the laurilic alcohol was utilized in the flotation to promote the separation. The experiments have been performed with a synthetic wastewater, carefully prepared with xylene. The experimental data obtained using flotation presented a first order kinetic, identified by the quality of the linear data fitting. The best conditions were found at 0.029 g.L-1 for the surfactant EO 7, 0.05 g.L-1 for EO 8, 0.07 g.L-1 for EO 9, 0.045 g.L-1 for EO 10 and 0.08 g.L-1 for EO 23 with the following estimated kinetic constants: 0.1765, 0.1325, 0.1210, 0.1531 and 0.1699 min-1, respectively. For the series studied, the most suitable surfactant was the EO 7 due to the lower reagent onsumption, higher separation rate constant and higher removal efficiency of xylene in the aqueous phase (98%). Similarly to the flotation, the photo-Fenton process shows to be efficient for degradation of xylene and promoting the mineralization of the organic charge around 90% and 100% in 90 min

Degradação fotoquímica de efluentes industriais contendo polipropileno e isoniazida

One of the main impacts to the environment is the water pollution, where the industrial sector is one of the main sources of this problem. In order to search for a solution, the industrial sector is looking forward to new technologies to treat its wastewaters with the goal to reuse the water in the own process. In this mode, the treatment presents a reduction in its costs with the water suply. One of these technologies that are getting more and more applications is the advanced oxidative processes (AOP´s). In this work two industrial wastewaters have been studied, i.e., containing polymers and pharmacus. In the case of the wastewaters with polymers the UV/H2O2 process has been applied with a systematic series of experiments, using irradiation from a mercury lamp and also solar. The following variables of the UV/H2O2 process for the polymers wastewaters have been studied systematically with the lamp reactor: mode of addition of hydrogen peroxide, temperature, time of reaction, hydrogen peroxide concentration and power of the lamp (80, 125, 250 and 400W). The results demonstrated to be satisfactory, obtaining rates of organic charge removal of 100% in 120 minutes of reaction. The studied variables for the experiments with solar irradiation using polymers wastewaters were only the time of reaction, the mode of addition and concentration of the hydrogen peroxide. The results with the solar irradiation demonstrated to be not satisfactory, reaching maximum of 22% of TOC removal in 240 minutes of reaction. This is in accordance with the fact that the solar source has only 5% of low UV irradiation. With respect to the photodegradation of the pharmacus wastewaters, the process UV/H2O2 and photo-Fenton have been applied. As a source of photons, in this case, a mercury UV lamp of 80 W has been used. The studied variables for the experiments with artificial irradiation with the pharmacus wastewaters were: initial concentration of the pollutant, concentration of Fe2+ and time of reaction. The results demonstrated a degree of degradation fairly satisfactory, showing a maximum conversion value of 46% in 120 minutes

Aplicação da água residuária das salinas no tratamento de efluente têxtil

The treatment of colored and alkaline effluent has been a challenge to the textile industry. An alternative to remove the colors of those effluents is applying magnesium chloride as a coagulant agent. The magnesium ion, in high pH, hydrolyzes itself, forming the magnesium hydroxide which has a large adsorptive area and positive electrostatic charges able to act as an efficient coagulant. The bittern wastewater from the salt industries has been studied as a potential font of this magnesium ion. Nowadays, this bittern wastewater is evicted into the sea, without any treatment or other use. This thesis has evaluated the potential of applying the wastewater from the salt industries in the treatment of dyeing effluent containing indigo dye and alkaline pH. All the experiments were made in jar tests simulating the chemical coagulation, flocculation and decantation steps ranging the pH and the concentration of magnesium ion. Were obtained removals between 96% and 76% for turbidity, apparent color, and true color, respectively, using 200mg/L Mg2+. The reduction of costs with acid, when were used the salt industries wastewater, comparing with Al2(SO4)3, was 62%. For the degradation of organic matter remaining in the clarified, around 900 mg/L, was applyed the advanced process of oxidation: photo-Fenton. The preliminary results showed 57% reduction in DOC. According to the results obtained, the salt industries wastewater can be applied, as coagulant, in the physical-chemical treatment of the denim dyeing wastewater, so it is not necessary a previous adjust of pH, efficiently and economically

Desenvolvimento de um sistema foto-oxidativo visando aplicação no tratamento de águas produzidas em campos de petróleo

Increasing concern with the environment, in addition to strict laws, has induced the industries to find altenatives to the treatment of their wastes. Actually, the oil industry has sought solutions to overcome a big environmental problem, i.e., oil field produced water being discharged to the sea. These effluents have organic compounds dissolved, such as polycyclic aromatic hydrocarbons, phenols, benzene, toluene, ethylbenzene and xylenes (BTEX). These compounds are difficult to be removed and have high toxicity. The advanced oxidation processes - AOP are effective to degradation of these organic compounds, because they generate hydroxyl radicals with high potential of oxidation. This work includes the reactor photochemical development applied in the photodegradation treatment (by photo-Fenton process) of wastewaters containing organic compounds dissolved, aiming at treatment and recovery the oil field produced water. The studied reactor allowed the evaluation of two ultraviolet radiation sources that is the main factor to describe the feasibility of the photo¬Fenton treatment, i.e., sun and black light fluorescent lamps, and other relevant variables the process: concentration of reagents, irradiated area and also various reactor configurations to maximize the use of radiation. The organic matter degradation was verified with samples collected during the experimental and analyzed with a total organic carbon analyzer (TOC), which expressed the results in terms of mgC/L. The solar radiation was more effective than radiation from the lamps. it's an important factor for the operation costs cutting. Preliminary experiments applied to oil field produced water treatment have showed satisfactory results, reducing up to 76 % of organic matter

Desenvolvimento de um sistema foto-oxidativo visando aplicação no tratamento de águas produzidas em campos de petróleo

Increasing concern with the environment, in addition to strict laws, has induced the industries to find alternatives to the treatment of their wastes. Actually, the oil industry has sought solutions to overcome a big environmental problem, i.e., oil field produced water being discharged to the sea. These effluents have organic compounds dissolved, such as polycyclic aromatic hydrocarbons, phenols, benzene, toluene, ethylbenzene and xylenes (BTEX). These compounds are difficult to be removed and have high toxicity. The advanced oxidation processes - AOP are effective to degradation of these organic compounds, because they generate hydroxyl radicals with high potential of oxidation. This work includes the reactor photochemical development applied in the photodegradation treatment (by photo-Fenton process) of wastewaters containing organic compounds dissolved, aiming at treatment and recovery the oil field produced water. The studied reactor allowed the evaluation of two ultraviolet radiation sources that is the main factor to describe the feasibility of the photo- Fenton treatment, i.e., sun and black light fluorescent lamps, and other relevant variables the process: concentration of reagents, irradiated area and also various reactor configurations to maximize the use of radiation. The organic matter degradation was verified with samples collected during the experimental and analyzed with a total organic carbon analyzer (TOC), which expressed the results in terms of mgC/L. The solar radiation was more effective than radiation from the lamps. It's an important factor for the operation costs cutting. Preliminary experiments applied to oil field produced water treatment have showed satisfactory results, reducing up to 76 % of organic matter

Análise dos Processos de Flotação e Oxidação Avançada para o Tratamento de Efluente Modelo da Indústria do Petróleo

The generation of wastes in most industrial process is inevitable. In the petroleum industry, one of the greatest problems for the environment is the huge amount of produced water generated in the oil fields. This wastewater is a complex mixture and present great amounts. These effluents can be hazardous to the environmental without adequate treatment. This research is focused in the analysis of the efficiencies of the flotation and photo-oxidation processes to remove and decompose the organic compounds present in the produced water. A series of surfactants derivated from the laurilic alcohol was utilized in the flotation to promote the separation. The experiments have been performed with a synthetic wastewater, carefully prepared with xylene. The experimental data obtained using flotation presented a first order kinetic, identified by the quality of the linear data fitting. The best conditions were found at 0.029 g.L-1 for the surfactant EO 7, 0.05 g.L-1 for EO 8, 0.07 g.L-1 for EO 9, 0.045 g.L-1 for EO 10 and 0.08 g.L-1 for EO 23 with the following estimated kinetic constants: 0.1765, 0.1325, 0.1210, 0.1531 and 0.1699 min-1, respectively. For the series studied, the most suitablesurfactant was the EO 7 due to the lower reagent consumption, higher separation rate constant and higher removal efficiency of xylene in the aqueous phase (98%). Similarly to the flotation, the photo-Fenton process shows to be efficient for degradation of xylene and promoting the mineralization of the organic charge around 90% and 100% in 90 min

Degradação de fármacos residuais por processos oxidativos avançados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photodegradation of dichloroacetic acid and 2,4-dichlorophenol by ferrioxalate/H2O2 system

The photo-Fenton process using potassium ferrioxalate as a mediator in the photodegradation reaction of organochloride compounds in an aqueous medium was investigated. The influence of parameters such as hydrogen peroxide and ferrioxalate concentrations and initial pH, was evaluated using dichloroacetic acid (DCA) as a model compound under black-light lamp irradiation. An upflow annular photoreactor, operating in a single pass or recirculating mode was used during photodegradation experiments with artificial light. The extent of the release of chloride ions was used to evaluate the photodegradation reaction. The optimum pH range observed was 2.5-2.8. The efficiency of DCA dechlorination increased with increasing concentrations of H2O2 and potassium ferrioxalate, reaching a plateau after the addition of 6 and 1.5 mmol/L of those reagents, respectively. The total organic carbon (TOC) content in DCA and 2,4-dichlorophenol (DCP) solutions was compared with the chloride released after photodegradation. The influence of natural solar light intensity, measured at 365 nm, was evaluated for the dechlorination of DCA on typical summer's days showing a linear dependency. The photodegradation of DCA using black-light lamp and solar irradiation was compared.

Heterogeneous photocatalytic treatment of organic dyes in air and aqueous media

This review focuses on the heterogeneous photocatalytic treatment of organic dyes in air and water. Representative studies spanning approximately three decades are included in this review. These studies have mostly used titanium dioxide (TiO2) as the inorganic semiconductor photocatalyst of choice for decolorizing and decomposing the organic dye to mineralized products. Other semiconductors such as ZnO, CdS, WO3, and Fe2O3 have also been used, albeit to a much smaller extent. The topics covered include historical aspects, dark adsorption of the dye on the semiconductor surface and its role in the subsequent photoreaction, semiconductor preparation details, photoreactor configurations, photooxidation kinetics/mechanisms and comparison with other Advanced Oxidation Processes (e.g., UV/H2O2, ozonation, UV/O3, Fenton and photo-Fenton reactions), visible light-induced dye decomposition by sensitization mechanism, reaction intermediates and toxicity issues, and real-world process scenarios. © 2008 Elsevier B.V. All rights reserved.

Influência da estrutura de corantes azo na cinética de degradação por processo foto-Feton e ferro zero e na toxicidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da matriz na degradação do fármaco bezafibrato por processo foto-Feton

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Degradação de antibióticos sulfonamidas por processo foto-Feton: identificação de intermediários

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fotodegradação de fármacos por procesos oxidativos avançados utilizando fonte de irradiação artificial e solar: avaliação química e toxicológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Degradação do corante comercial disperse red1 por processo foto-Feton e avaliação ecotoxicológica

Pós-graduação em Química - IQ