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Recuperação de Eu(III) e U(VI) de efluentes aquosos utilizando a técnica de membranas líquidas suportadas (MLS) e macrocíclicos como agentes extratores; RECOVERY IONS Eu(III) AND U(VI) FROM AQUEOUS EFFLUENTS USING THE SUPPORTED LIQUID MEMBRANES (SLM) TECHNIQUE AND MACROCYCLICS AS EXTRACTOR AGENTS

Santos, Jacinete Lima dos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/10/2007 PT
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46.38%
Este trabalho apresenta um estudo sobre a síntese e caracterização de novos agentes extratores da família dos calixarenos, utilizados com a técnica de membranas líquido suportadas para recuperar íons Eu(III) e U(VI) de efluentes aquosos. Os novos agentes extratores, os n-acetatocalix[n]arenos ( n= 4, 6 e 8), foram obtidos a partir da reação de acetilação dos p-terc-butilcalix[n]arenos (n = 4, 6 e 8) com anidrido acético e caracterizados por: análise elementar de CHN, espectroscopia vibracional na região do infravermelho, espectroscopia de absorção na região do UV-Vis, ressonância magnética nuclear RMN 1H, análise termogravimétrica e testes de solubilidade. Os compostos obtidos foram usados em estudos de distribuição líquido-líquido e também na técnica de membranas líquido suportadas (MLS), utilizando suportes poliméricos de 0,45, 1,2 e 5 m. A partir dos resultados da análise de caracterização verificou-se a funcionalização dos calixarenos. Tanto os calixarenos não funcionalizados quanto os funcionalizados mostraram-se bastante efetivos para extração de íons Eu(III) e U(VI). Da análise dos resultados concluiu-se que: a eficiência de extração é dependente do pH. Para íons Eu(III) a máxima eficiência de extração foi alcançada em pH 4 e 5 e para o U(VI) em pH 7. Os solventes utilizados...

Degradação de 2,4-diclorofenol em solução aquosa por meio de processo fotoquímico solar.; Degradation of 2,4-dichlorophenol in aqueous solution by means of solar photochemical process.

Resende, Juliana Dalia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/02/2011 PT
Relevância na Pesquisa
36.16%
O 2,4-diclorofenol (2,4-DCF), poluente modelo usado neste trabalho, é um composto empregado na produção de pesticidas, herbicidas e anti-sépticos, e comumente encontrado em efluentes industriais, sendo considerado um poluente prioritário devido a sua elevada toxicidade e alto poder de persistência no ambiente. Este trabalho objetivou estudar a degradação do 2,4-DCF em reator fotoquímico tubular com coletores parabólicos compostos (CPC) irradiado pelo Sol, operado em batelada com recirculação e admissão contínua de peróxido de hidrogênio à vazão de 11 mL min-1. A oxidação do poluente foi baseada no processo foto-Fenton catalisado por tris(oxalato) ferrato(III) (FeOx), investigando-se os efeitos das seguintes variáveis: concentração inicial de 2,4-DCF ([2,4-DCF] = 21-520 mgCL-1), concentrações de oxidante ([H2O2] = 9,9-130 Mm) e de fotocatalisador ([FeOx] = 0,2-1,8 mM) e área de coleta de fótons (0,196-0,98 m2), estudadas a partir de um planejamento Doehlert em múltiplos níveis. A foto-oxidação foi monitorada por medidas da concentração de carbono orgânico total (TOC) e oxigênio dissolvido (OD), tendo sido identificadas condições com remoção de TOC alcançando 99,8% em 90 minutos de tratamento. Nas análises estatísticas dos resultados...

Degradação do antibiótico ciprofloxacina em solução aquosa por meio de processo oxidativo avançado baseado em ozônio.; Degradation of the antibiotic ciprofloxacin in aqueous solution by the advanced oxidation process based on ozone.

Baptistucci, Cíntia Bardauil
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/03/2012 PT
Relevância na Pesquisa
36.24%
Os tratamentos convencionais de efluentes em geral não são eficientes para a degradação de compostos persistentes como os fármacos. Neste trabalho, estuda-se o tratamento de soluções aquosas contendo o antibiótico ciprofloxacina (CIP) por meio de processo oxidativo avançado baseado em ozônio. Para tanto, foram realizados experimentos em semi-batelada com recirculação de líquido em um reator (coluna de bolhas) com escoamento gás-líquido em contracorrente. Amostras de líquido foram retiradas e analisadas para medida das concentrações de CIP e de carbono orgânico total (COT); a concentração de ozônio no gás foi medida por espectrofotometria UV-vis. Estudaram-se os efeitos das seguintes variáveis quanto à degradação de CIP, por meio de um planejamento Doehlert: concentração de ozônio à entrada do reator (8-25 mgO3 L-1), pH (3,5-10,5) e concentração inicial de CIP (5-26 mg L-1). Avaliaram-se as seguintes variáveis dependentes por meio da análise de superfícies de resposta: variação de concentração de CIP em 2 minutos; taxa inicial de degradação de CIP e variação de concentração de COT em 30 minutos. Os resultados indicaram total degradação de ciprofloxacina em menos de 15 minutos, tanto por via direta...

Photodegradation of soluble and emulsive cutting fluids using TiO 2 as catalyst

Araújo, Adriana B.; Amarante Jr., Ozelito P.; Vieira, Eny M.; Valente, José P. S.; Padilha, Pedro M.; Florentino, Ariovaldo O.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 737-740
ENG
Relevância na Pesquisa
36.16%
This paper describes results of the photo-degradation of three types of soluble and emulsive cutting fluids in an aqueous medium, using TiO2 as catalyst in suspension and UV radiation. The TiO2 proved to be an effective catalyst for the degradation of the cutting fluids investigated. The degradation rate depends on pH and nature of the fluids. The best performance of catalyst was observed at pH 8.0 for all the fluids when most of 70% of the organic load was decomposed. ©2006 Sociedade Brasileira de Química.

Photoelectrocatalysis based on Ti/TiO2 nanotubes removes toxic properties of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 from aqueous chloride samples

Ferraz, E. R A; Oliveira, G. A R; Grando, M. D.; Lizier, T. M.; Zanoni, Maria Valnice Boldrin; Oliveira, D. P.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 108-114
ENG
Relevância na Pesquisa
36.24%
This work describes the efficiency of photoelectrocatalysis based on Ti/TiO2 nanotubes in the degradation of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 and to remove their toxic properties, as an alternative method for the treatment of effluents and water. For this purpose, the discoloration rate, total organic carbon (TOC) removal, and genotoxic, cytotoxic and mutagenic responses were determined, using the comet, micronucleus and cytotoxicity assays in HepG2 cells and the Salmonella mutagenicity assay. In a previous study it was found that the surfactant Emulsogen could contribute to the low mineralization of the dyes (60% after 4h of treatment), which, in turn, seems to account for the mutagenicity of the products generated. Thus this surfactant was not added to the chloride medium in order to avoid this interference. The photoelectrocatalytic method presented rapid discoloration and the TOC reduction was ≥87% after 240min of treatment, showing that photoelectrocatalysis is able to mineralize the dyes tested. The method was also efficient in removing the mutagenic activity and cytotoxic effects of these three dyes. Thus it was concluded that photoelectrocatalysis was a promising method for the treatment of aqueous samples. © 2013 Elsevier Ltd.

Treatment of aqueous effluents contaminated with ionic liquids; Tratamento de efluentes aquosos contaminados com líquidos iónicos

Marques, Carlos Filipe Conceição
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
ENG
Relevância na Pesquisa
46.8%
Este trabalho visa o tratamento de efluentes aquosos contaminados com líquidos iónicos (LIs). Os LIs são sais que a temperaturas inferiores a 373 K e à pressão atmosférica permanecem no estado líquido. Isto deve-se ao tamanho e assimetria dos iões envolvidos na composição dos LIs que os faz apresentar propriedades distintas dos sais convencionais. Dado a serem compostos por iões, os LIs podem ser sintetizados consoante uma determinada finalidade e/ou propriedades necessárias para uma aplicação específica. Por apresentarem pressões de vapor desprezáveis, estes não poluem a atmosfera e têm sido, por isso, considerados solventes menos agressivos para o meio ambiente. No entanto, estes compostos apresentam um solubilidade não desprezável em água, o que por outro lado, pode conduzir à poluição de efluentes aquosos quando se antecipa, num futuro próximo, o uso destes solventes à escala industrial. Neste trabalho foram estudados dois processos de remoção e recuperação de LIs de fases aquosas: adsorção (para o caso de LIs hidrofóbicos, e logo, pouco solúveis em água e com uma concentração baixa nos efluentes aquosos); e sistemas aquosos bifásicos (para os LIs hidrofílicos, miscíveis com água, e que apresentam concentrações mais elevadas nos efluentes aquosos). Para o estudo do processo de adsorção o adsorvente usado foi o carvão ativado...

Treatment of aqueous effluents contaminated with ionic liquids; Tratamento de efluentes aquosos contaminados com líquidos iónicos

Neves, Catarina Maia Seco Seiça
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
46.37%
Ionic liquids are a class of solvents that, due to their unique properties, have been proposed in the past few years as alternatives to some hazardous volatile organic compounds. They are already used by industry, where it was possible to improve different processes by the incorporation of this kind of non-volatile and often liquid solvents. However, even if ionic liquids cannot contribute to air pollution, due to their negligible vapour pressures, they can be dispersed thorough aquatic streams thus contaminating the environment. Therefore, the main goals of this work are to study the mutual solubilities between water and different ionic liquids in order to infer on their environmental impact, and to propose effective methods to remove and, whenever possible, recover ionic liquids from aqueous media. The liquid-liquid phase behaviour of different ionic liquids and water was evaluated in the temperature range between (288.15 and 318.15) K. For higher melting temperature ionic liquids a narrower temperature range was studied. The gathered data allowed a deep understanding on the structural effects of the ionic liquid, namely the cation core, isomerism, symmetry, cation alkyl chain length and the anion nature through their mutual solubilities (saturation values) with water. The experimental data were also supported by the COnductor-like Screening MOdel for Real Solvents (COSMO-RS)...

Comparative Study of Commercial Oxide Electrodes Performance in Electrochemical Degradation of Organics in Aqueous Solutions

Pelegrino,Rosângela L.; Di Iglia,Rosana A.; Sanches,Caio G.; Avaca,Luis A.; Bertazzoli,Rodnei
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2002 EN
Relevância na Pesquisa
36.22%
In this paper the potentiality of two types of DSAâ commercial electrodes, for electrochemical treatment of effluents, is investigated. Oxide anodes, with nominal composition of 70TiO2/30RuO2 and 45IrO2/55Ta2O5, were used in a flow-cell reactor for the electrooxidation of phenol. Comparative results were presented as phenol concentration decay as a function of electrolysis time, as well as COD and TOC concentration reduction. The cell reactor was operated at current densities, ranging from 15 to 150 mA cm-2 and solution linear velocity was 0.24 m s-1. Results reported in this paper showed that phenol and quinones were degraded to a very low concentration, besides only a small portion of the organic carbon is reduced. Starting from 100 mg L-1, after five hours of electrolysis at 100 mA cm-2, concentrations reached 0.4 mg L-1 of phenol, 1 mg L-1 of hydroquinone, 7 mg L-1 of benzoquinone and TOC was reduced by 35%.

Photodegradation of soluble and emulsive cutting fluids using TiO2 as catalyst

Araújo,Adriana B.; Amarante Junior,Ozelito P.; Vieira,Eny M.; Valente,José P. S.; Padilha,Pedro M.; Florentino,Ariovaldo O.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2006 EN
Relevância na Pesquisa
36.16%
This paper describes results of the photo-degradation of three types of soluble and emulsive cutting fluids in an aqueous medium, using TiO2 as catalyst in suspension and UV radiation. The TiO2 proved to be an effective catalyst for the degradation of the cutting fluids investigated. The degradation rate depends on pH and nature of the fluids. The best performance of catalyst was observed at pH 8.0 for all the fluids when most of 70% of the organic load was decomposed.

Application of Carbon Composite Adsorbents Prepared from Coffee Waste and Clay for the Removal of Reactive Dyes from Aqueous Solutions

Santos,Davis C. dos; Adebayo,Matthew A.; Lima,Eder C.; Pereira,Simone F. P.; Cataluña,Renato; Saucier,Caroline; Thue,Pascal S.; Machado,Fernando M.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 EN
Relevância na Pesquisa
36.49%
A novel carbon composite was prepared from a mixture of coffee waste and clay with inorganic:organic ratio of 1.3 (CC-1.3). The mixture was pyrolysed at 700 °C. Considering the application of this adsorbent for removal of anionic dyes, the CC-1.3 was treated with a 6 mol L-1 HCl for 24 h to obtain ACC-1.3. Fourier transform infrared (FTIR), N2 adsorption/desorption curves, scanning electron microscope (SEM) and powder X-ray diffractometry (XRD) were used for characterisation of CC-1.3 and ACC-1.3 carbon adsorbents. The adsorbents were effectively utilised for removal of reactive blue 19 (RB-19) and reactive violet 5 (RV-5) textile dyes from aqueous solutions. The maximum amounts of RB-19 dye adsorbed at 25 °C are 63.59 (CC-1.3) and 110.6 mg g-1 (ACC-1.3), and 54.34 (CC-1.3) and 94.32 mg g-1 (ACC-1.3) for RV-5 dye. Four simulated dye-house effluents were used to test the application of the adsorbents for treatment of effluents.

Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

Vieira,M. G. A.; Almeida Neto,A. F. de; Silva,M. G. C. da; Carneiro,C. N.; Melo Filho,A. A.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
36.22%
This study evaluated the kinetic adsorption of Pb and Cu ions using rice husk ash as adsorbent in a fixed bed. The maximum adsorption capacities obtained for lead and copper ions in the fixed bed were 0.0561 and 0.0682 mmol/g (at 20 ºC), respectively. The thermodynamic studies indicated that the lead adsorption process was exothermic and spontaneous, while the copper adsorption process was endothermic and spontaneous. Characterization results indicated the presence of several functional groups, amorphous silica and a fibrous and longitudinal structure of rice husks. Rice husk ash (RHA) from northern Brazil can be used as a bioadsorbent for the individual removal of Pb(II) and Cu(II) ions from metal-containing effluents.

Removal of Cr(VI) from Aqueous Solutions Using Powder of Potato Peelings as a Low Cost Sorbent

Mutongo, Farai; Kuipa, Olga; Kuipa, Pardon K.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.16%
Potato peels which are a low cost, renewable agroindustry by-product were used for the removal of hexavalent chromium from aqueous effluents. Batch experiments were carried out with an artificial effluent comprising of potassium dichromate in deionised water. The effects of the initial hexavalent chromium concentration, dose of biosorbent, and removal kinetics were explored. An adsorbent dosage of 4 g/L was effective in complete removal of the metal ion, at pH 2.5, in 48 minutes. The kinetic process of Cr(VI) adsorption onto potato peel powder was tested by applying pseudo-first-order and pseudo-second-order models as well as the Elovich kinetic equation to correlate the experimental data and to determine the kinetic parameters. The adsorption data were correlated by the Langmuir and Freundlich isotherms. A maximum monolayer adsorption capacity of 3.28 mg/g was calculated using the Langmuir adsorption isotherm, suggesting a functional group limited adsorption process. The results confirmed that potato peels are an effective biosorbent for the removal of hexavalent chromium from effluent.

Comparison of Spirulina platensis microalgae and commercial activated carbon as adsorbents for the removal of Reactive Red 120 dye from aqueous effluents

Cardoso, Natali Farias; Lima, Eder Claudio; Royer, Betina; Bach, Marta; Dotto, Guilherme Luiz; Pinto, Luiz Antônio de Ameida; Calvete, Tatiana
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.57%
Spirulina platensis microalgae (SP) and commercial activated carbon (AC) were compared as adsorbents to remove Reactive Red 120 (RR-120) textile dye from aqueous effluents. The batch adsorption system was evaluated in relation to the initial pH, contact time, initial dye concentration and temperature. An alternative kinetic model (general order kinetic model) was compared with the traditional pseudo-first order and pseudo-second order kinetic models. The equilibrium data were fitted to the Langmuir, Freundlich and Liu isotherm models, and the thermodynamic parameters were also estimated. Finally, the adsorbents were employed to treat a simulated dye-house effluent. The general order kinetic model was more appropriate to explain RR-120 adsorption by SP and AC. The equilibrium data were best fitted to the Liu isotherm model. The maximum adsorption capacities of RR-120 dye were found at pH 2 and 298 K, and the values were 482.2 and 267.2 mg g−1 for the SP and AC adsorbents, respectively. The thermodynamic study showed that the adsorption was exothermic, spontaneous and favourable. The SP and AC adsorbents presented good performance for the treatment of simulated industrial textile effluents, removing 94.4–99.0% and 93.6–97.7%, respectively...

Estudo dos parâmetros de extração de fenol de efluentes aquosos por um tensoativo não iônico; Study of phenol extraction parameters of aqueous effluents by a non-ionic surfactant

Silva, Wanessa Paulino Neves
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Química; Pesquisa e Desenvolvimento de Tecnologias Regionais Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia Química; Pesquisa e Desenvolvimento de Tecnologias Regionais
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.56%
Environmental sustainability has become one of the topics of greatest interest in industry, mainly due to effluent generation. Phenols are found in many industries effluents, these industries might be refineries, coal processing, pharmaceutical, plastics, paints and paper and pulp industries. Because phenolic compounds are toxic to humans and aquatic organisms, Federal Resolution CONAMA No. 430 of 13.05.2011 limits the maximum content of phenols, in 0.5 mg.L-1, for release in freshwater bodies. In the effluents treatment, the liquid-liquid extraction process is the most economical for the phenol recovery, because consumes little energy, but in most cases implements an organic solvent, and the use of it can cause some environmental problems due to the high toxicity of this compound. Because of this, exists a need for new methodologies, which aims to replace these solvents for biodegradable ones. Some literature studies demonstrate the feasibility of phenolic compounds removing from aqueous effluents, by biodegradable solvents. In this extraction kind called "Cloud Point Extraction" is used a nonionic surfactant as extracting agent of phenolic compounds. In order to optimize the phenol extraction process, this paper studies the mathematical modeling and optimization of extraction parameters and investigates the effect of the independent variables in the process. A 32 full factorial design has been done with operating temperature and surfactant concentration as independent variables and...

Remoção eletroquimica de fenol em efluentes aquosos utilizando celula de fluxo com anodo tridimensional do tipo ADE'Marca Registrada'; Eletrochemical removal of phenol from aqueous effluents by using a flow cell with a DSA type three dimensional anode

Rosana Aparecida Di Iglia
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/12/2002 PT
Relevância na Pesquisa
46.38%
Os compostos fenólicos são amplamente utilizados, principalmente na produção de plásticos, resinas e na indústria petroquímica, gerando efluentes com alta toxicidade. Os tratamentos existentes, embora eficientes, demandam adição de grandes quantidades de reagentes, no caso da oxidação química, ou grandes áreas físicas, longos tempo de retenção e difícil controle do processo, no caso da degradação biológica. O objetivo deste trabalho é desenvolver e otimizar dois reatores eletroquímicos de fluxo utilizando anodos comerciais de óxidos de metais nobres para eletroxidação de fenol: um com anodo plano e outro com anodo tridimensional sendo ambos do tipo ADE® de Ti/RuO2 - TiO2. A inovação tecnológica deste processo de tratamento consiste no uso destes anodos usados em larga escala na indústria de álcalis e que além da alta resistência à corrosão e da boa atividade catalítica, podem ser confeccionados em diversos formatos e tamanhos. Este projeto foi desenvolvido em 4 etapas: 1) Construção dos reatores; 2) Estudo voltamétrico das reações do eletrodo; 3) Ensaios de eletroxidação de fenol e 4) Comparação do desempenho dos reatores. A caracterização e análise elementar do eletrodo tridimensional por MEV determinou sua composição como (TiO2)0...

Decolorization of aqueous effluents using agro waste

Apostol, L.; Pereira, Luciana; Alves, M. M.; Gavrilescu, Maria
Fonte: Institutul Politehnic din Iasi Publicador: Institutul Politehnic din Iasi
Tipo: Artigo de Revista Científica
Publicado em /03/2012 ENG
Relevância na Pesquisa
46.66%
In this study, the potential of agrowaste for a food dye sequestration from aqueous effluents was investigated. Initially, four local agrowaste waste namely pumpkin seed hull, bean null, oat straw and nut shells, were tested in natural condition. Bean hull (BH) revealed the best uptake capacity for Food Red 14 (FR14). The agro waste was characterised before and after dye sorption process using SEM and FTIR techniques. Those analyses were conducted in order to identify the principal connections contributing to the sorption process. The point of zero charge of BH surface, pHpzc was assessed at 4.6, which indicated a mostly acidic surface, favorable for dye adsorption at pH<6, when the sorbent is positively charged. The dye removal efficiency of the adsorbent has been established in relation to some factors, such as: pH, amount of adsorbent, dye initial concentration, contact time and temperature. In order to make the sorption process predictable, four empirical isotherms and four kinetics models were applied to the experimental data so as to enact the nature of the sorption process. Attempts have also been made for sorbent viability by testing different solvents for FR14 desorption. FTIR spectra reveal the main bands in FR14 sorption process: that at 1450 cm-1 corresponding to C=C bond from the aromatic ring appears greatly diminished for FR14-BH after the sorption process and suggests a horizontal orientation of the molecules. The movement of the band at 3442 cm-1...

Chromium uptake from aqueous effluents by immobilized Baker's yeast

Menezes,Lucia Beckmann C.; Braz,Vera Nobre; Cordeiro,Carlos Alberto M.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/1998 EN
Relevância na Pesquisa
36.49%
Baker’s yeast immobilized in alginate was used to take up chromium from effluents. Chromium in aqueous solutions were used in different concentrations. To evaluate the viability and efficiency the baker’s yeast for chromium uptake from effluents three experiments done in two differents reactor systems: first in system 1 at 17.5 ml/s and with 10, 20, 25 and 30 mg/l Cr; second in system 2 at 38.7 ml/s with 20 mg/l Cr; third in system 2.1 at 6.65 ml/s and with 20, 30 and 40 mg/l Cr. The efficiency of chromium uptake varied between 86 and 100 %.

Posibilidades sobre el uso de residuos de la industria del acero en la eliminación de metales de efluentes líquidos; Possibilities of using steelmaking industry residues in the removal of metals from liquid effluents

Martín Hernández, María Isabel; López Gómez, Félix Antonio; López-Delgado, Aurora; Pérez, C.; Alguacil, Francisco José
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo Formato: 137295 bytes; application/pdf
SPA
Relevância na Pesquisa
36.38%
A study is made of the removal of metals present in aqueous effluents using a residue of the steelmaking industry denominated rolling mill scale. Mill scale can be considered a cheap material for the removal of toxic metals due to its high content in iron oxides and metallic iron. A study of the removal of Cd2+, Zn2+, Pb2+ y Cu2+ ions from aqueous solutions was made, studying several variables that affect the process. The removal of cadmium, zinc and lead corresponding to a superficial adsorption process, was evaluated using the theories of Langmuir and Freundlich. The removal of copper occurs through a process of oxidationreduction or cementation (Cu2+/Fe). The possibilities of desorption were studied too.; Se estudia la eliminación de metales presentes en efluentes acuosos empleando un residuo de la industria del acero denominado cascarilla de laminación. La cascarilla se puede considerar como un material barato para la eliminación de metales tóxicos por su alto contenido en óxidos de hierro y hierro metálico. Se ha realizado un estudio de la eliminación de los iones Cd2+, Zn2+, Pb2+ y Cu2+ contenidos en soluciones acuosas, estudiándose diversas variables que afectan al proceso. La eliminación de cadmio, cinc y plomo correspondiente a un proceso de adsorción superficial...

Métodos para Remoção de Derivados Fenólicos de Efluentes Aquosos; Methods for the Removal of Phenolic Derivatives from Aqueous Effluents

Felipe S. Cunha; Instituto Militar de Engenharia; Alcino P. de Aguiar; Instituto Militar de Engenharia
Fonte: Revista Virtual de Química Publicador: Revista Virtual de Química
Tipo: ; Formato: binary/octet-stream
Publicado em 27/06/2014
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Derivados fenólicos são compostos que não ocorrem naturalmente em corpos d’água. A presença de fenóis no meio ambiente está associada à atividade humana. Estes compostos são encontrados em rejeitos de diferentes tipos de indústrias, tais como: petroquímica, papel e celulose, farmacêutica, têxtil, mineradoras, coquerias, entre outras. A legislação brasileira estabelece o valor de 0,5 mg/L como a concentração máxima destes derivados em água. Entretanto, no efluente de algumas indústrias a concentração pode alcançar  2000 mg/L. Este artigo reporta as principais técnicas utilizadas para remoção de derivados fenólicos de efluentes aquosos industriais, tais como: oxidação por ar úmido, degradação biológica, uso de adsorventes orgânicos ou inorgânicos. Adicionalmente, são apresentados alguns aspectos associados à toxidez destes poluentes.  DOI: 10.5935/1984-6835.20140052; Phenolic derivatives are compounds that do not occur naturally in water. The presence of phenols in environment is due to human activity. These compounds have been detected in effluents from different industries, such as: petrochemical, pulp and paper, pharmaceutical, textile, coal mining, coke industry, etc. The Brazilian Law establishes the value of 0.5 mg/L as maximum concentration of these derivatives in water...

AN INTEGRATED REMEDIATION SYSTEM USING SYNTHETIC AND NATURAL ZEOLITES FOR TREATMENT OF WASTEWATER AND CONTAMINATED SEDIMENTS

RIOS REYES,CARLOS; APPASAMY,DANEN; ROBERTS,CLIVE
Fonte: DYNA Publicador: DYNA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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The major sources of water pollution can be classified as municipal, industrial, and agricultural. Different types of polluted aqueous effluents and sediments may be produced, which contain relatively high levels of heavy metals. During the 1990s, the large-scale development of constructed wetlands around the world drew much attention from public and environmental groups. The present study looks at the use of an integrated remediation system using zeolites for the treatment of wastewater and sediments. Zeolites have been widely studied in the past 10 years due to their attractive properties such as molecular-sieving, high cation exchange capacities, and their affinity for heavy metals. Coal industry by-products-based zeolites (faujasite type) have been tested as an effective and low-cost novel alternative for wastewater treatment, particularly their removing of heavy metals. On the other hand, a preliminary laboratory-scale experiment was conducted on the use of natural zeolites (clinoptilolite type) for the retention of heavy metals from canal sediments. Experimental work revealed promising results, which could be replicated on a bigger scale. Although this has been developed for canal sediments, the remediation strategy can be adapted to different waterways such as rivers. The development of the proposed remediation system in a specific experimental site as the major part of an innovation park can provide great benefits to a population living near contaminated effluents. It provides not only opportunities for the mitigation of environmental impact...