Adsorption of hexavalent chromium onto organic bentonite modified by the use of iron(III) chloride

2014 ◽  
Vol 70 (4) ◽  
pp. 664-670 ◽  
Author(s):  
Jianchao Hao ◽  
Leilei Xiao ◽  
Huifen Liu ◽  
Lijun Shi ◽  
Xiaoyan Xu ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Molecular Sieves ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
Adsorption Ability ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Coated Material ◽  
Calcium And Magnesium ◽  
Organic Bentonite

The adsorption of hexavalent chromium (Cr(VI)) was improved by using organic bentonite (OB) modified with iron(III) chloride. The adsorption mechanisms and characteristics of OB and organic bentonite modified by FeCl3 (FMOB) were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDS). It was found that hydroxyl-iron replaced some of the calcium and magnesium contained in the FMOB, but no significant change in its structure was shown even though the adsorption experiments proved that FMOB had a better Cr(VI) adsorption ability compared to OB. The coated material was prepared by mixing FMOB and 4A molecular sieves in a coated pot for the adsorption experiments in the test column. The relevant results showed that the adsorption of the coated material retained its high adsorption ability and maintained that ability after desorption and regeneration, which implied a potential for further application.

Leaching Studies of Cement-Glass Package Containing Sodium Borate

1986 ◽  
Vol 84 ◽  
Author(s):  
Masahiro Okamoto ◽  
Koichi Chino ◽  
Tsutomu Baba ◽  
Tatsuo Izumida ◽  
Fumio Kawamura ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Liquid Waste ◽  
Sodium Borate ◽  
Pressurized Water Reactor ◽  
X Ray Diffraction ◽  
Adsorption Ability ◽  
Pressurized Water ◽  
X Ray ◽  
Solidification Reaction ◽  
Main Components

AbstractA new solidification technique using cement-glass, which is a mixture of sodium silicate, cement, additives, and initiator of the solidification reaction, was developed for sodium borate liquid waste generated from pressurized water reactor (PWR) plants. The cement-glass could solidify eight times as much sodium borate as cement could, because the solidifying reaction of the cement-glass is not hindered by borate ions.The reaction mechanism of sodium silicate and phosphoric silicate (initiator), the main components of cement-glass, was studied through X-ray diffraction and compressive strength measurements. It was found that three- dimensionally bonded silicon dioxide was produced by polymerization of the two silicates. The leaching ratio of cesium from the cement-glass package was one-tenth that of the cement one. This low value was attributed to a high cesium adsorption ability of the cement-glass and it could be theoretically predicted accordingly.

scholarly journals Investigation of Adsorption Behavior of Cu2O Submicro-Octahedra towards Congo Red

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xu Zhang ◽  
Ying Zhang ◽  
Dong Wang ◽  
Fengyu Qu
Keyword(s):  
Cuprous Oxide ◽  
Congo Red ◽  
Adsorption Behavior ◽  
X Ray Diffraction ◽  
Adsorbed Species ◽  
Adsorption Ability ◽  
Chemical Additive ◽  
X Ray ◽  
Short Time ◽  
Facile Route

Perfect cuprous oxide (Cu2O) nanocrystals with octahedron shape were successfully synthesized by a facile route without chemical additive in a short time. The products were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The adsorption ability of the products towards congo red (CR) as the pollutant was investigated and FTIR spectroscopy was employed to identify the adsorbed species. The adsorption behavior was analyzed based on the microstructure of Cu2O submicro-octahedra.

Adsorption Capacity of Y Zeolite Using Organic Solvents such as Adsorbates

2014 ◽  
Vol 805 ◽  
pp. 641-645
Author(s):  
Ana Paula Araújo ◽  
Aline Cadigena Lima Patrício ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Small Molecules ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
High Adsorption ◽  
X Ray ◽  
Low Concentrations ◽  
Adsorption Of Nitrogen ◽  
Type Zeolite

The zeolites differ from traditional adsorbents for selective adsorption of small molecules, the high adsorption capacity at low concentrations and affinity for organic compounds and unsaturated polar molecules. In this work a Y-type zeolite was synthesized, characterized by x-ray diffraction, scanning electron microscopy and adsorption of nitrogen and subjected to test adsorption capacity where it was found that the Y zeolite has the potential adsorption capacity compared to other materials being studied and marketed.

Replacing sulfonate by carboxylate: application of pyridyliminocarboxylato copper(II) complexes in rac-lactide polymerization and Chan–Evans–Lam coupling

2019 ◽  
Vol 97 (3) ◽  
pp. 178-190 ◽  
Author(s):  
Valérie Hardouin Duparc ◽  
Clémentine Dimeck ◽  
Frank Schaper
Keyword(s):  
Molecular Sieves ◽  
Weight Control ◽  
Phenylboronic Acid ◽  
Side Reactions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
X Ray ◽  
Induction Periods ◽  
Lactide Polymerization

Copper(II) complexes carrying pyridylmethyleneaminobenzoate or –propanoate ligands, LCuX, were prepared in one-pot reactions from pyridinecarboxaldehyde, aminobenzoic acid or β-alanine, and CuX2 (X = Cl, NO3, OAc, or OTf). All complexes were characterized by single-crystal X-ray diffraction studies and formed either dimers, tetramers, or coordination polymers. Attempted preparation of the respective alkoxide complexes, LCu(OR), was unsuccessful, but use of LCuX/NaOMe mixtures in rac-lactide polymerization indicated under some conditions coordination–insertion polymerization via a copper alkoxide as the mechanism. The complexes performed poorly in rac-lactide polymerization, showing low activities (12 h to completion at 140 °C), low to moderate heterotacticity (Pr = 0.6–0.8), and poor polymer molecular weight control (intramolecular transesterification). They were competent catalysts for Chan–Evans–Lam couplings with phenylboronic acid, without any indication of side reactions such as deboration or aryl homocoupling. The complexes were active in undried methanol, without addition of base, ligand, or molecular sieves. Aniline, n-octylamine, and cyclohexylamine were coupled quantitatively under identical reaction conditions. There is only little influence of the anion on activities (less than a factor of 2) but a strong influence on induction periods. The complexes were not active in CEL coupling with alcohols, phenols, or alkylboronic acids.

Removeal of Arsenic(III) from Water by Using a New Class of Zero-Valent Iron Modified Mesoporous Silica Molecular Sieves SBA-15

2011 ◽  
Vol 356-360 ◽  
pp. 423-429
Author(s):  
Meng Ye ◽  
Jin Huang ◽  
Rui Chen ◽  
Qi Zhuang He
Keyword(s):  
Molecular Sieves ◽  
Cost Effective ◽  
Zero Valent Iron ◽  
Preparation Process ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray ◽  
New Class ◽  
Transmission Electron ◽  
Removal Of Arsenic

An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using Zero-Valent iron (ZVI) to remove As from water is a proven technology. In this study, ZVI modified SBA-15 mesoporous silicamolecular sieves (ZVI-SBA-15), was prepared, characterized, and used for removing arsenic from water. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to ZVI by NaBH4, and the ZVI modified SBA-15 was obtained. Fourier-transform infrared spectroscopy confirmed the preparation process of the nitrate to oxide forms. The structure of the materials was confirmed by Powder X-ray diffraction. Its data indicated that the structure of ZVI-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating ZVI-SBA-15 coating on the inner surfaces. Transmission electron micrographs also confirmed that modified SBA-15 retained the structure of the parent SBA-15 silica.It has a high uptake capability(more than 90 pecent) make it potentially attractive absorbent for the removal of arsenic from water.

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.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

Elucidating the CO2 adsorption mechanisms in the triangular channels of the bis(pyrazolate) MOF Fe2(BPEB)3 by in situ synchrotron X-ray diffraction and molecular dynamics simulations

2017 ◽  
Vol 5 (32) ◽  
pp. 16964-16975 ◽  
Author(s):  
C. Giacobbe ◽  
E. Lavigna ◽  
A. Maspero ◽  
S. Galli
Keyword(s):  
Molecular Dynamics ◽  
Co2 Adsorption ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
Computational Tools ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Metal Organic ◽  
Dynamics Simulations

The structural origin of the remarkable performance of the metal–organic framework Fe2(BPEB)3 as a CO2 adsorbent (40.5% of the host weight at 298 K and 10 bar) was investigated by combining advanced experimental and computational tools.

X-ray diffraction and solid-state n.m.r. studies of AEL molecular sieves: Effect of hydration

Zeolites ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Roger Khouzami ◽  
Gisèle Coudurier ◽  
Fréderic Lefebvre ◽  
Jacques C. Vedrine ◽  
Bernard F. Mentzen
Keyword(s):  
Solid State ◽  
Molecular Sieves ◽  
X Ray Diffraction ◽  
X Ray
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