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Degrada??o de corantes têxteis e remedia??o de resíduos de tingimento por processos Fenton, foto-Fenton e eletro-Fenton
Salvador, Terezinha;Marcolino Jr., Luiz H.;Peralta-Zamora, Patricio;
Química Nova , 2012, DOI: 10.1590/S0100-40422012000500013
Abstract: in this work the degradation of textile dyes were evaluated, using fenton, photo-fenton and electro-fenton processes. under optimized conditions fenton and photo-fenton processes showed high decolorization capacity of the model dyes. the electro-fenton process was carried out in an undivided electrochemical reactor (1000 ml) equipped with a carbon-felt cathode (253 cm2) and a platinum gauze anode (6 cm2). under optimal conditions (j: 1.6 ma cm-2, na2so4: 0.075 mol l-1, ph: 3) h2o2 concentration of about 60 mg l-1 was observed. the addition of fe2+ (15 mg l-1) induces fenton reactions that permit almost total decolorization of textile dyes.
Degrada??o de benzeno, tolueno e xilenos em águas contaminadas por gasolina, utilizando-se processos foto-Fenton
Tiburtius, Elaine Regina Lopes;Peralta-Zamora, Patricio;Emmel, Alexandre;
Química Nova , 2009, DOI: 10.1590/S0100-40422009000800014
Abstract: in this work the potentiality of photo-fenton processes were investigated toward the degradation of aromatic hydrocarbons (btxs) from water contaminated with gasoline. the main results demonstrated that btxs can be quickly degraded by photo-fenton process assisted by solar or artificial uv-a radiation, degradation that leads to generation of characteristic phenolic transient species (ie. phenol, hydroquinone and catechol). in the treatment of contaminated water by photo-fenton processes assisted by solar light, complete btxs removal was observed in reaction times of about 5 min. mineralization of about 90% was also observed by applying a multiple h2o2 addition system.
Tratamento de banhos de tingimento têxtil por processos foto-Fenton e avalia??o da potencialidade de reuso
Zanella, Geovani;Scharf, Mauro;Vieira, Giovana Aparecida;Peralta-Zamora, Patricio;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000500006
Abstract: in this work the treatment of textile dyeing baths by a sequential reductive-oxidative process was evaluated, aiming its utilization in new dyeing process. the results demonstrated that reactive dyes can be easily degraded by reductive processes mediated by zero-valent iron, a fact that induces decolorizations of about 80%. sequential photo-fenton processes permit almost total removal of the residual color with elimination of 90% of the cod content. the reuse of treated residues permits the achievement of materials that attend practically all textile specifications, with exception of the color difference parameter (δe), which is unsatisfactory toward the importation standards, but adequate for the national market.
Esferas de quitosana/Fe na degrada??o do corante Azul QR-19 por processos foto-Fenton utilizando luz artificial ou solar
Souza, Kely V. de;Zamora, Patrício G.P.;Zawadzki, S?nia F.;
Polímeros , 2010, DOI: 10.1590/S0104-14282010005000035
Abstract: the contamination of water resources is one of the greatest environmental problems today. among the polluting sources are the textile industries due to the production of large volumes of effluent, often treated inefficiently. the main reason for the environmental impact of the rejected materials is the presence of dyes such as azo reactive compounds that can generate by-products with carcinogenic and mutagenic effects. they may also include anthraquinone type compounds, which are highly resistant to degradation and persist in the effluent for a long time. the purpose of this study is the use of photo-fenton processes assisted by artificial or solar light, using immobilized iron on chitosan beads, crosslinked with glutaraldheyde, for the antraquinone type compound blue qr-19 standard dye degradation in aqueous solutions. the obtained spheres showed a regular size and 4.0 mm diameter. the results showed 90% discolouration of the system within 180 minutes and a 60% total organic carbon (toc) reduction for the photo-fenton system using artificial light. for the system using sunlight, the total discolouration was achieved in 120 minutes and the toc value decreased 70%. also observed was that iron remained in the polymeric matrix after the treatment, thus allowing reuse.
Fenton Processes as an Alternative to the Removal of Endocrine Disruptors and other Environmental Pollutants [Processos Fenton como Alternativa na Remo o de Interferentes Endócrinos e outros Micropoluentes Ambientais]
Mariana Roberto Gama
Revista Virtual de Química , 2012,
Abstract: Technological advances, combined to high levels of consumption by the population, led to an increase in the generation of waste, which compromise the availability of natural resources, especially water resources. Furthermore, sensitive analytical detections have increased the detection of environmental micropollutants, many highly toxic. Therefore, the search for alternatives to the removal of micropollutants from water is necessary to overcome the methods currently available. Advanced oxidative processes are efficient for the removal of micropollutants. This review summarizes the main aspects of environmental contamination by endocrine disruptors and the use of Fenton reactions as advanced oxidation processes in the removal of these micropollutants.
Descolora??o de efluentes aquosos sintéticos e têxtil contendo corantes índigo e azo via processos Fenton e foto-assistidos (UV e UV/H2O2)
Salgado, Bruno César Barroso;Nogueira, Maria Ionete Chaves;Rodrigues, Kelly Araújo;Sampaio, Glória Maria Marinho Silva;Buarque, Hugo Leonardo de Brito;Araújo, Rinaldo dos Santos;
Engenharia Sanitaria e Ambiental , 2009, DOI: 10.1590/S1413-41522009000100001
Abstract: in the present work, advanced oxidation processes, fe2+/h2o2 and uv/h2o2, and direct photolysis (uv light) have been applied in the decolorization of two synthetic wastewater containing indigo and azo dyes and laundry effluent. individual aqueous solutions containing 20 mg/l indigo carmine and congo red dyes (43 μmol/l and 29 μmol/l, respectively) and textile laundry wastewater at ph 3 were subjected to different experimental conditions in the oxidation reactions at room temperature (27 oc). color and cod removals were evaluated for each oxidation systems. the results showed that the utilized processes are able to successfully decolorize the wastewaters. complete bleaching was achieved by fenton and uv/h2o2. also, kinetics investigations revealed that the decolorization follows pseudo-first order kinetic with respect to the dye concentration.
DEGRADACIóN DEL AEDT Y LOS COMPLEJOS Cu(II)-AEDT Y Cr(III)-AEDT MEDIANTE LOS PROCESOS FENTON Y FOTO-FENTON ASISTIDO CON RADIACIóN SOLAR EN SOLUCIONES ACUOSAS  [cached]
Araceli DELFíN PAZOS,Carlos Antonio PINEDA ARELLANO,Susana SILVA MARTíNEZ
Revista internacional de contaminación ambiental , 2009,
Abstract: La degradación del ácido etilendiaminotetraacético (AEDT) y de los complejos organometálicos Cu(II)-AEDT y Cr(III)-AEDT se llevaron a cabo en un sistema por lotes, empleando los procesos Fenton y foto-Fenton asistidos con radiación solar. Se estudió el efecto del pH sobre la degradación de los complejos metal-AEDT y se evaluaron diferentes relaciones molares de [H2O2]: [AEDT]. Se observó que la presencia de hierro incrementa la degradación de los complejos. También se observó degradación del complejo Cu(II)-AEDT en la reacción Fenton asistido con luz solar y estando ausente el ión hierro a pH 3. La concentración inicial de los sustratos estudiados se abatió en más de 80 % con foto-Fenton.
Imobiliza??o de ferro (II) em matriz de alginato e sua utiliza??o na degrada??o de corantes têxteis por processos Fenton
Souza, Kely Viviane de;Peralta-Zamora, Patricio;Zawadzki, S?nia Faria;
Química Nova , 2008, DOI: 10.1590/S0100-40422008000500041
Abstract: in this work fenton and photo-fenton processes for textile dye degradation were investigated using iron (ii) immobilized in alginate spheres. photomicrographs obtained by scanning electron microscopy showed an irregular and porous surface with a homogeneous distribution of iron. the fenton process was used to evaluate the degradation efficiency of reactive dyes and this procedure showed a low degradation effect. the association of artificial visible light or solar radiation in the fenton process (foto-fenton process) showed degradation ratios of 70 and 80% respectively in 45 min. it was also observed that the iron-alginate matrix can be reused.
Solar photo-Fenton optimisation in treating carbofuran-contaminated water Optimización del proceso foto-Fenton solar para el tratamiento de agua contaminada con Carbofurano  [cached]
Hernández-Shek Manuel Alejandro,Agudelo Henao Ana Cecilia,Mendoza Marín Claudia,Torres Casta?eda Harlen
Ingeniería e Investigación , 2012,
Abstract: Box-Benkhen design response-surface methodology was developed to optimise photo-Fenton degradation of carbofuran (C12H15NO3) by using a compound parabolic collector pilot plant. The four variables considered in Box-Benkhen design model included carbofuran degradation percentage, initial carbofuran concentration, hydrogen peroxide [H2O2] concentration and iron [Fe2+] concentration. Degradation was monitored by using total organic carbon concentration and high-performance liquid chromatography. A 93.2 mg l-1 carbofuran concentration was completely degraded in t30W = 15 min with 17.1 mg l-1 Fe2+ and 121.6 mg l-1 H2O2. Photo-Fenton degradation led to 76.7% mineralisation. Biodegradability during optimisation was evaluated by using the BOD5/COD ratio; this value increased from 0.04 at the beginning of the process to 0.52 in t30W = 20 min, thereby showing the effectiveness of using biological treatments. Se desarrolló una metodología de superficie de respuesta, dise o Box-Benkhen, con el fin de optimizar el proceso foto-Fenton para la degradación de carbofurano (C12H15NO3) usando una planta piloto de colectores solares cilindro-parabólicos. El modelo Box-Benkhen incluyó cuatro variables: porcentaje de degradación de carbofurano, concentración inicial de carbofurano, concentración de peróxido de hidrógeno [H2O2] y concentración de hierro [Fe2+]. El proceso de degradación fue monitoreado a través de la concentración de carbono orgánico total y cromatografía líquida de alta resolución. Los resultados mostraron que una concentración de 93,2 mg l-1 de carbofurano se degradó completamente en un tiempo t30W = 15 min con 17,1 mg l-1 de Fe2+ y 121,6 mg l-1 de H2O2. El proceso foto-Fenton alcanzó 76,7% de mineralización. La biodegradabilidad fue evaluada usando la relación DBO5/DQO; este valor incrementó desde 0,04 hasta 0,52 en t30W = 20 min, mostrando la posibilidad de usar un tratamiento biológico a partir de ese momento.
Sistema de inje??o em fluxo espectrofotométrico para monitorar peróxido de hidrogênio em processo de fotodegrada??o por rea??o foto-Fenton
Oliveira, Mirela C.;Nogueira, Raquel F. Pupo;Gomes Neto, José A.;Jardim, Wilson F.;Rohwedder, Jarbas J. R.;
Química Nova , 2001, DOI: 10.1590/S0100-40422001000200007
Abstract: a flow injection spectrophotometric system was projected for monitoring hydrogen peroxide during photodegradation of organic contaminants in photo-fenton processes (fe2+/h2o2/uv). sample is injected manually in a carrier stream and then receives by confluence a 0.1 mol l-1 nh4vo3 solution in 0.5 mol l-1 h2so4 medium. the product formed shows absorption at 446 nm which is recorded as a peak with height proportional to h2o2 concentration. the performance of the proposed system was evaluated by monitoring the consumption of h2o2 during the photodegradation of dichloroacetic acid solution by foto-fenton reaction.
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