Characterization of a tropical soil and a waste from kaolin mining and their suitability as heterogeneous catalysts for Fenton and Fenton-like reactions

Clay Minerals ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 299-306 ◽  
Author(s):  
M. C. Pereira ◽  
C. M. Tavares ◽  
J. D. Fabris ◽  
R. M. Lago ◽  
E. Murad ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Chemical Analysis ◽  
Iron Oxides ◽  
Heterogeneous Catalysts ◽  
Tropical Soil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Fenton System

AbstractAlternative Fenton and Fenton-like systems based on natural Fe oxides are described. The collected materials were modified through controlled reduction with H2 and were characterized by chemical analysis, X-ray diffraction, saturation magnetization measurements, and Mössbauer spectroscopy at 298 and 110 K. The catalytic activities of these original and modified materials were tested by studying the decomposition of H2O2 and the discolouration of methylene blue. Iron oxides present in the samples were mainly hematite and subordinate goethite which, after controlled reduction, were converted to metallic iron and magnetite. The mixture of Fe0 and magnetite in one of these materials was significantly more efficient at H2O2 decomposition and the discolouration of methylene blue than the original Fe3+ oxides. These results suggest that Fe2+ is essential to produce an active Fenton system.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

Purification of Bentonite Clays from Cubati, PB, Brazil, for Diversified Applications

2014 ◽  
Vol 805 ◽  
pp. 486-491
Author(s):  
J.M.R. Figueirêdo ◽  
Juliana Melo Cartaxo ◽  
I.A. Silva ◽  
C.D. Silva ◽  
Gelmires Araújo Neves ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Analysis ◽  
Laser Diffraction ◽  
The State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granulometric Analysis ◽  
Bentonite Clays

The State of Paraíba, Brazil, retains about 88.5% of all Brazilian bentonite, and much of this production comes from deposits in the District of Boa Vista, PB. Nevertheless, the deposits are almost depleted. Recently, new deposits were found, which will increases the reserves of the State, in the regions of Cubati and Pedra Lavrada, PB. The objective of this work is to characterize and develop purified clays, through sieving and hydrocycloning techniques, from those recently discovered bentonites for several applications. The characterization of the sample was done through granulometric analysis by laser diffraction, X-ray diffraction, chemical analysis by X-ray fluorescence, and thermogravimetric and differential thermal analysis. The results show that the samples are typical of bentonite clays, and that the purification solely by hydrocyclone presents the best results.

scholarly journals In-Exchanged CHA Zeolites for Selective Dehydrogenation of Ethane: Characterization and Effect of Zeolite Framework Type

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 807
Author(s):  
Zen Maeno ◽  
Xiaopeng Wu ◽  
Shunsaku Yasumura ◽  
Takashi Toyao ◽  
Yasuharu Kanda ◽  
...  
Keyword(s):  
Active Sites ◽  
Temperature Programmed Desorption ◽  
X Ray Diffraction ◽  
Zeolite Framework ◽  
X Ray ◽  
Catalytic Activities ◽  
Ethane Dehydrogenation ◽  
Temperature Programmed

In this study, the characterization of In-exchanged CHA zeolite (In-CHA (SiO2/Al2O3 = 22.3)) was conducted by in-situ X-ray diffraction (XRD) and ammonia temperature-programmed desorption (NH3-TPD). We also prepared other In-exchanged zeolites with different zeolite structures (In-MFI (SiO2/Al2O3 = 22.3), In-MOR (SiO2/Al2O3 = 20), and In-BEA (SiO2/Al2O3 = 25)) and different SiO2/Al2O3 ratios (In-CHA(Al-rich) (SiO2/Al2O3 = 13.7)). Their catalytic activities in nonoxidative ethane dehydrogenation were compared. Among the tested catalysts, In-CHA(Al-rich) provided the highest conversion. From kinetic experiments and in-situ Fourier transform infrared (FTIR) spectroscopy, [InH2]+ ions are formed regardless of SiO2/Al2O3 ratio, serving as the active sites.

Microstructural Characterization of Ornamental Rock Samples: Cariri Rocks

2016 ◽  
Vol 869 ◽  
pp. 159-163
Author(s):  
Danúbia Lisbôa da Costa ◽  
Ingrid Mayara Medeiros Fernandes ◽  
Aluska Nascimento Simões Braga ◽  
Rosiane Maria da Costa Farias ◽  
Romualdo Rodrigues Menezes ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Microstructural Characterization ◽  
Magnesium Carbonate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Sector ◽  
Microstructural Heterogeneity ◽  
Calcium And Magnesium ◽  
Application Fields

Ornamental rocks are among the most promising business areas of the mineral sector, raising the necessity for, besides beauty, investments in quality, safety and characterization in the various application fields of these rocks. So, this work aims at the microstructural characterization of the class of these rocks: the Cariri Rocks, also known the limestone, which are calcareous rocks mainly formed by calcium and magnesium carbonate, possibly presenting variations due to their origins. For characterization, we studied four samples, being two from Chapada do Apodi and two from Chapada do Araripe, characterized physically and micro-structurally through chemical analysis, X-ray diffraction, optical micrography and porosimetry tests. The results prove that the limestones are calcitic and dolomitic, and present porosity varying from 5 to 15%, with pores concentration between 100nm and 10μm, besides the high microstructural heterogeneity.

scholarly journals CHARACTERIZATION OF CLAYS IN THE ZINDER REGION BY X-RAY DIFFRACTION AND X-RAY FLUORESCENCE METHODS

2020 ◽  
Vol 8 (12) ◽  
pp. 1088-1095
Author(s):  
Abdoulkader Moussa Issaka ◽  
◽  
Bouba Hassane ◽  
Ibrahim Wagani ◽  
Amadou Abdourhamane Toure ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorescence Methods ◽  
Composite Samples ◽  
Mineralogical Phases

In order to characterizeclays of the Zinder region, 20 samples were taken from the quarries of Magaria, Mirriah, Guidimouni and Kolleram and four composite samples were made and representative of the quarries. These samples were subjected to chemical and mineralogical analyzes. Chemical analysis shows that the materials from these four quarries are aluminosilicates, but in varying proportions. The samplesfrom the Magaria and Kolleramquarries, contain proportions of carbonwhichinducethem a blackishcolor and alkaline and alkaline-earthelements (CaO, K2O, MgO. The samplesfromMirriah and Guidimouni,are veryrich in ironoxide (Fe2O3) whichinduces a reddishcolor. The main mineralogical phases detected by X-ray diffraction in the rawsamples and fine fractions from the four quarrieswere kaolinite, a mica structure close to illite and quartz.Thesequarriesthenconstitutekaolinicdeposits, primary and secondary. Those of Magaria and Kolleram are secondary and less favorable to formulations of ceramicproducts and those of Mirriah and Guidimouni are primary and very favorable to formulations of ceramicproductssuch as potteryfromMirriah.

Molecular orientation of methylene blue intercalated in layer-charge-controlled montmorillonites

2003 ◽  
Vol 18 (11) ◽  
pp. 2639-2643 ◽  
Author(s):  
Yoshiro Kaneko ◽  
Nobuo Iyi ◽  
Juraj Bujdák ◽  
Ryo Sasai ◽  
Takektoshi Fujita
Keyword(s):  
Methylene Blue ◽  
Molecular Orientation ◽  
Layer Charge ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Charge Densities ◽  
Clay Surface ◽  
Host Materials

The effect of the layer-charge density of clay on the orientation and aggregation of a cationic dye, methylene blue (MB), in MB/clay films was investigated using a series of layer-charge-controlled montmorillonites as host materials. Polarized ultraviolet-visible spectroscopy and x-ray diffraction were used for the characterization of the arrangement and orientation of dye cations in host interlayer spaces. It was revealed that high charge densities of layers induced the formation of relatively ordered and homogeneous phases with dye dimers. The reduction of the charge led to the formation of disordered, mixed phases with large amounts of monomers (isolated dye cations). Dimers and monomers were slightly tilted against the plane of the clay surface, and their angles were not affected by the layer charge.

Characterization of Clay from Vale do Mulembá - ES

2008 ◽  
Vol 591-593 ◽  
pp. 487-492 ◽  
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
J.C.G. Correia ◽  
A. Caranassios
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Thermal Analyses ◽  
The Other ◽  
High Plasticity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Studies ◽  
And Behavior

This work has for objective to characterize the clay from Vale do Mulembá-ES. The Vale do Mulembá is located in Joana D´Arc, Vitória in Espírito Santo State, Brazil. That clay is used in the production of the traditional clay pans of the State, what contributes to the economy of the area. The clay from Vale do Mulembá presents characteristics and behavior different from the other clays used for the production of clay pans. The characterization studies were carried out through chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analyses (DTA, TGA). The results showed that the clay is typical kaolinitic, present relatively to the amount high of Al2O3 and high plasticity.

Synthesis and Characterization of Tantalum Based Photocatalysts and Application for Methylene Blue Degradation

2016 ◽  
Vol 855 ◽  
pp. 147-155
Author(s):  
Meghshyam K. Patil ◽  
Hari C. Bajaj ◽  
Rajesh J. Tayade
Keyword(s):  
Methylene Blue ◽  
Diffuse Reflectance ◽  
Mixed Oxides ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Methylene Blue Degradation ◽  
Degradation Study ◽  
X Ray

Ta2O5, Ta2O5–SrO and Ta2O5–TiO2 photocatalysts were prepared by hydrothermal method and characterized using X-ray diffraction (XRD), Ultraviolet-visible Diffuse Reflectance spectroscopy (UV-Vis DRS) and Thermogravimetry (TGA). In synthesized series of TiO2-Ta2O5 catalysts, formation of anatase TiO2, hexagonal Ta2O5 and titanium tantalates were observed. For Ta2O5-SrO (Ta:Sr= 1:1) formation of mixed oxide and crystallinity was observed at calcinations temperature at 1100 °C (5hr). These synthesized catalysts were used for degradation study of methylene blue. The result demonstrated that the photocatalytic activity of the mixed oxides [Ta2O5-TiO2(1:1), Ta2O5-TiO2(2:1), Ta2O5-TiO2(1:2), Ta2O5-SrO (Ta:Sr= 1:1)] was higher than that of Ta2O5 alone.

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