scholarly journals ON THE CHARACTERISTICS OF ALKALI- AND ACID- ACTIVATED BENTONITE OF KOSOVO TO BE USED FOR OIL RECYCLING

2021 ◽  
Vol 11 (2) ◽  
pp. 331-336
Author(s):  
Valdet Teneqja ◽  
◽  
Arjan Korpa ◽  
Spiro Drushku ◽  
Arianit Reka ◽  
...  
Keyword(s):  
Activated Bentonite

Application of Activated Bentonite Impregnated with PdO as Green Catalyst for Acylation Reaction of Aromatic Compounds

2021 ◽  
pp. 105508
Author(s):  
Yehezkiel Steven Kurniawan ◽  
Arif Cahyo Imawan ◽  
Yoeretisa Miggia Stansyah ◽  
Tutik Dwi Wahyuningsih
Keyword(s):  
Aromatic Compounds ◽  
Acylation Reaction ◽  
Green Catalyst ◽  
Activated Bentonite

scholarly journals Maximum Bleaching of Vegetable Oils by Acid-Activated Bentonite: Influence of Nanopore Radius

2012 ◽  
Vol 30 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Müsęerref Önal ◽  
Yüksel Sarıkaya
Keyword(s):  
Vegetable Oils ◽  
Bleaching Earth ◽  
Nitrogen Adsorption ◽  
Mass Range ◽  
Acid Mixture ◽  
Acid Activation ◽  
Physicochemical Interaction ◽  
Activated Bentonite ◽  
The Mean ◽  
Bleaching Power

The optimum conditions necessary for preparing a bleaching earth (BE) with maximum bleaching power (BP) towards soybean oil (SO) and cottonseed oil (CSO) were investigated. BEs were obtained by H2SO4 activation of a white calcium bentonite (CaB) sample from the Kütahya region of Turkey. After drying for 4 h at 105 °C, the CaB samples were activated by heating their acidic aqueous suspensions for 6 h at 97 °C, the acid content of the dry bentonite/acid mixture being varied in the 0–70% mass range. The respective specific surface area (S) and specific nanopore volume (V) of the BEs were determined from nitrogen adsorption/desorption data obtained at −196 °C. For natural CaB, the values of S and V were 44 m2/g and 0.11 cm3/g, respectively. These values attained a maximum of 135 m2/g and 0.30 cm3/g for the BE sample prepared employing 40% H2SO4 for acid activation. Interestingly, the maximum BP was not associated with the maximum S and V values. The optimum values for the percentage H2SO4, S and V for attaining the maximum BP were 20%, 100 m2/g and 0.17 cm3/g, respectively. The mean nanopore radius (r) of each BE was calculated using the corresponding S and V values. Nanopores with a mean radius in the range 3.5–5.5 nm, which was close to the diameter of the coloured pigment, were found to be mostly responsible for the BP towards SO and CSO. The results obtained in the present study indicate that the value of r was more effective than the S and V values of BEs in the bleaching of vegetable oils. Adsorption of a pigment onto a BE was found to depend not only on the physicochemical interaction between the pigment molecule and the BE surface, but also on the mean nanopore size.

Effect of Environmental Materials on Aqueous Corrosion of R7T7 Glass

1988 ◽  
Vol 127 ◽  
Author(s):  
N. Godon ◽  
E. Vernaz ◽  
J. H. Thomassin ◽  
J. C. Touray
Keyword(s):  
Atmospheric Pressure ◽  
Test Results ◽  
Aqueous Corrosion ◽  
Environmental Material ◽  
Environmental Materials ◽  
Activated Bentonite ◽  
Order Of Magnitude ◽  
Glass Specimen ◽  
Icp Analysis ◽  
Glass Behavior

ABSTRACTR7T7 glass behavior was investigated in contact with eleven different materials including smectites, bentonites, illites, granite and sand. The experiments were conducted at 90°C under atmospheric pressure with a 4 cm−1 SA/V ratio using two grams of material in double distilled water under static leaching conditions without renewal of the leachate. For each material a control test was conducted under the same conditions but without the glass specimen, as well as a series of tests on glass alone, without the environmental material. Kinetics studies lasting up to 364 days were performed on four selected materials.The test results (mass loss, ICP analysis of the leachates, SEM and TEM observations) showed relatively slight glass alteration in contact with sand, granite and one bentonite (i.e. the same order of magnitude as glass alone in deionized water), but greater alteration of glass in contact with all the other clays.The significant differences in glass behavior in contact with environmental materials can be accounted for by the behavior of the latter in solution: activated bentonite releases very large amounts of silicon and sodium into solution while smectite seems to remove silicon from solution.

Influence of the physical-chemistry properties of an acid-activated bentonite in the bleaching of olive oil

2007 ◽  
Vol 57 (3) ◽  
pp. 213-216 ◽  
Author(s):  
E. González-Pradas ◽  
M. Villafranca-Sánchez ◽  
A. Gallego-Campo
Keyword(s):  
Physical Chemistry ◽  
Olive Oil ◽  
Activated Bentonite

scholarly journals The adsorption characteristics and porous structure of bentonite adsorbents, determined from the adsorption isotherms of benzene vapor

2004 ◽  
Vol 69 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Snezana Brezovska ◽  
Biljana Marina ◽  
Biljana Panova ◽  
Donco Burevski ◽  
Vasa Bosevska ◽  
...  
Keyword(s):  
Free Energy ◽  
Porous Structure ◽  
Pore Size ◽  
Adsorption Isotherms ◽  
Micropore Volume ◽  
Benzene Vapor ◽  
Free Energy Of Adsorption ◽  
Volume Filling ◽  
Activated Bentonite ◽  
Characteristic Values

The adsorption of benzene vapor on natural and acid activated bentonites was treated by the theory of volume filling of micropores. The micropore volume and characteristic values of the free energy of adsorptionwere determined from the adsorption isotherms. The Dubinin?Radushkevish?Stoeckli and Dubinin?Astakhov equations were used for this purpose. The results showed that natural bentonite has a more homogeneous micropore structure than the acid activated ones. The characteristic values of the free energy of adsorption for the natural bentonite were higher than those of the acid activated bentonite. This is due to differences in its structure and the pore size.

scholarly journals Application of activated bentonite for the removal of direct and reactive dye from aqueous solutions

2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic
Keyword(s):  
Aqueous Solutions ◽  
Dye Adsorption ◽  
Bentonite Clay ◽  
Reactive Dye ◽  
Second Order ◽  
Intra Particle Diffusion ◽  
Naoh Solution ◽  
Activated Bentonite ◽  
Endothermic Process ◽  
Pseudo Second Order

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.

scholarly journals COMPOSITION, STRUCTURE AND TEXTURAL CHARACTERISTICS OF DOMESTIC ACID ACTIVATED BENTONITE

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Zоrаn Pеtrоvić ◽  
Pеrо Dugić ◽  
Vојislаv Аlеksić ◽  
Sаbinа Bеgić ◽  
Vlаdаn Мićić ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Low Temperature ◽  
Layered Structure ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Textural Characteristics ◽  
X Ray ◽  
Before And After ◽  
Activated Bentonite ◽  
Composition Structure

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.

The role of normal and activated bentonite on the pelletization of barite iron ore concentrate and the quality of pellets

2003 ◽  
Vol 130 (1-3) ◽  
pp. 277-282 ◽  
Author(s):  
O.A Mohamed ◽  
M.E.H Shalabi ◽  
N.A El-Hussiny ◽  
M.H Khedr ◽  
F Mostafa
Keyword(s):  
Iron Ore ◽  
Activated Bentonite ◽  
Iron Ore Concentrate
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