Hexavalent Chromium
Mostrando 1-12 de 52 artigos, teses e dissertações.
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1. Yellow Mombin (Spondias mombin L.) Seeds from Agro-Industrial Waste as a Novel Adsorbent for Removal of Hexavalent Chromium from Aqueous Solutions
The objective of this study was to develop a low-cost and eco-friendly adsorbent from agro-industrial waste for the removal of hexavalent chromium in the aqueous medium. The adsorbent (BMC) produced from yellow mombin (Spondias mombin L.) seeds was characterized by the determination of the chemical composition, thermal analysis (thermogravimetric (TG) analys
J. Braz. Chem. Soc.. Publicado em: 2021-02
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2. Preparation and application of Zero Valent Iron immobilized in Activated Carbon for removal of hexavalent Chromium from synthetic effluent
RESUMO Diferentemente dos contaminantes orgânicos, os metais pesados não são biodegradáveis e tendem a se acumular nos organismos vivos e também são reconhecidos por serem tóxicos ou carcinogênicos. A utilização de nanopartículas de ferro zero valente (nFVZ) é relatada como uma técnica alternativa e de elevado potencial para remediação in situ
Rev. Ambient. Água. Publicado em: 03/10/2019
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3. Corrosion protection in sulfate medium by self-assemb films adsorbed on AA 2024 T3 aluminum alloy surface
In this study, the corrosion protection provided by films of self-assembled molecules on the AA 2024-T3 aluminum alloy has been evaluated by electrochemical and non electrochemical techniques. The film was obtained by immersion of this alloy samples in a solution of 90 mg L-1 alkane-diphosphonate at 50 °C for 5 minutes. Chromating conversion treatment with
Matéria (Rio J.). Publicado em: 2015-06
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4. Biosorption of Mn (II), Co (II) and Cr (VI) in a horizontal rotating tubular bioreactor: experiments and evaluation of the integral bioprocess model
In this research, a multi heavy metals removal process with mixed microbial culture was examined in a horizontal rotating tubular bioreactor (HRTB) with different combinations of process parameters. Three metals were selected as examples of cations (manganese and cobalt) and oxy-anion (hexavalent chromium). Hydrodynamic conditions and biomass sorption capaci
Braz. J. Chem. Eng.. Publicado em: 2014-09
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5. Punica granatum L. protects mice against hexavalent chromium-induced genotoxicity
Este estudo investigou os efeitos quimioprotetores do extrato alcoólico dos frutos da Punica granatum L. (Punicaceae) (EPG) em camundongos expostos ao cromo hexavalente [Cr(VI)]. Os animais foram pré-tratados com o EPG (25, 50 ou 75 mg/kg/dia) durante 10 dias e subsequentemente expostos a uma dose subletal de Cr(VI) (30 mg/kg). A frequência de eritrócito
Braz. J. Pharm. Sci.. Publicado em: 2013-12
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6. Hexavalent chromium reduction by immobilized cells of Bacillus sphaericus AND 303
Bacillus sphaericus AND 303, a Cr(VI)-resistant and reducing bacterium reported from serpentine outcrops of Andaman was evaluated for Cr(VI) reduction using immobilized cells under batch culture. Screening of inert matrices for entrapment of whole cells indicated that polyvinyl alchohol-alginate was the most effective one reducing 87.5% of 20 µM Cr(VI) in 2
Braz. arch. biol. technol.. Publicado em: 2013-06
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7. Desenvolvimento de um método analítico baseado em microextração líquido-líquido para a determinação de cromo (VI) em amostras aquosas com detecção por espectrometria de absorção atômica em chama
In this study, a method for determination of hexavalent chromium in aqueous samples using liquid-liquid microextraction (LLME) and detection by Flame Atomic Absorption Spectrometry (F AAS) was developed. The LLME procedure was based on the extraction of Cr (VI) by acetone at a sample pH of 1.2. The use of saturated ammonium sulphate solution allowed effectiv
Quím. Nova. Publicado em: 2013
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8. Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden
Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gramnegative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast e
Braz. J. Microbiol.. Publicado em: 2013
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9. Chi-square analysis of the reduction of ATP levels in L-02 hepatocytes by hexavalent chromium
This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bi
Brazilian Journal of Medical and Biological Research. Publicado em: 2012-06
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10. Caracterização da resistência à corrosão de ligas de alumínio após tratamentos alternativos à cromatização, com e sem revestimento orgânico / Characterization of the corrosion resistance of aluminum alloys after alternative treatmentes the chromate, with and without organic coating
In this study, the protective properties provided by new surface treatments for aluminum aiming the replacement of treatments that are harmful to the environment and human health, have been evaluated. The following treatments were investigated: passivation in solution with trivalent chromium ions, surface modification with self assembling molecules (SAM), im
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/03/2011
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11. SOLUÇÃO TAMPÃO QUE MIMETIZA AS CARACTERÍSTICAS ÁCIDO-BASE DO TAMPÃO SMP EM RESPOSTA À ACIDEZ DE SOLOS BRASILEIROS / A BUFFER SOLUTION THAT MIMICS THE ACID-BASE CHARACTERISTICS OF THE SMP BUFFER IN RESPOSNSE TO THE ACIDITY OF BRAZILIAN SOILS
No Brasil, o tampão SMP vem sendo utilizado desde a década de 60 como o principal método para a estimativa da acidez potencial e/ou da necessidade de calcário do solo. No entanto, em sua composição, a solução SMP apresenta p-nitrofenol e cromato de potássio, substâncias essas com elevado potencial de contaminação ambiental e capazes de promover o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/02/2011
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12. The influence of Chromium supplied by tanning and wet finishing processes on the formation of cr(vi) in leather
Chromium used in leather manufacturing can be oxidized from the trivalent to the hexavalent state, causing environmental concerns. In this study, the influence of Cr(III) from tanning, deacidification pH, fatliquors, chrome retanning and vegetable retanning on the formation of Cr(VI) in leather was analyzed by comparing natural and aged samples. In wet-blue
Brazilian Journal of Chemical Engineering. Publicado em: 2011-06