scholarly journals Adsorbate—Adsorbate Association in a One-Component Mobile Adsorption Phase on Energetically Homogeneous Adsorbents

1997 ◽  
Vol 15 (9) ◽  
pp. 695-705 ◽  
Author(s):  
J.K. Garbacz ◽  
A. Kopkowski
Keyword(s):  
Adsorption Phase ◽  
Experimental Adsorption ◽  
Adsorption Data ◽  
Calculation Results ◽  
Mobile Adsorption

A new description of adsorbate-adsorbate association on energetically homogeneous adsorbents has been presented. Suitable relations have been formulated for the mobile adsorption of a single gas. Experimental adsorption data have been described theoretically by the equations derived. The calculation results demonstrate the good applicability of the proposed idea.

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

MD simulations of hydrogen diffusion in ZIF-11 with a force field fitted to experimental adsorption data

2015 ◽  
Vol 203 ◽  
pp. 132-138 ◽  
Author(s):  
P. Schierz ◽  
S. Fritzsche ◽  
W. Janke ◽  
S. Hannongbua ◽  
O. Saengsawang ◽  
...  
Keyword(s):  
Force Field ◽  
Hydrogen Diffusion ◽  
Md Simulations ◽  
Experimental Adsorption ◽  
Adsorption Data

scholarly journals Nonlinear regression for analysis of the uptake of KMnO4 from aqueous solutions onto natural marl

2021 ◽  
Vol 1204 (1) ◽  
pp. 012003
Author(s):  
E A Bouzeghaia ◽  
S Hafsi ◽  
N Gherraf
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Ph ◽  
Suitable Model ◽  
Surface Functional Groups ◽  
Experimental Adsorption ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Batch Technique ◽  
Formation Of Complexes

Abstract The present work aims to evaluate the performance of raw marl collected from the region of Oum El Bouaghi on the elimination of KMnO4 from aqueous solution. The adsorption capacities were studied using the batch technique as a function of pH, initial concentration and temperature. The maximum adsorption for KMnO4 was found to be 83.517% at pH 3.0. When the pH is low (pH<3.0), the uptake of KMnO4 occurs with an electrostatic attraction between the MnO4-ions and the surface proton groups, while at pH ≥3.0-8.0, the formation of complexes with the surface functional groups during the adsorption process and/or cation exchange are responsible for retention of Mn(II) ions onto marl. Experimental adsorption data were modeled with different nonlinear isotherms and kinetic models. Furthermore, statistical errors (SSE, SD, ARE, χ 2, R2 and R2 adj) were calculated to choose the suitable model. Langmuir isotherm was found to be best for fitting the experimental data. The calculated thermodynamic parameters indicated that adsorption process was physical, spontaneous and endothermic in nature. From this work, it was concluded that the natural marl can be used for effective elimination of KMnO4 from aqueous solution and wastewater.

scholarly journals Adsorption of Barium and Zinc Ions by Mesoporous TiO2 with Chemosorbed Carbonate Groups

2019 ◽  
Vol 20 (3) ◽  
pp. 282-290 ◽  
Author(s):  
H. Vasylyeva ◽  
I. Mironyuk ◽  
I. Mykytyn ◽  
N. Danyliyk
Keyword(s):  
Physical Adsorption ◽  
Mesoporous Tio2 ◽  
Order Kinetic ◽  
Zinc Ions ◽  
Experimental Adsorption ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Efficient Adsorbent ◽  
Agitation Time

In the present paper the mesoporous TiO2 with chemosorbed carbonate groups was investigated as an adsorbent for the removal of Zn2+ and Ba2+ cations from aqueous solutions. The dependence of the adsorption values of Zn2+ and Ba2+ on the agitation time, solution’s acidity, and modification of surface of TiO2 was determined. The process of Zn2+ and Ba2+ adsorption fit well by Lagergren’s pseudo-second-order kinetic model. The equilibrium adsorption was investigated in the concentration of heavy metal’s ranges 27.46 mg/L - 7809 mg/L. The experimental data was approximated by Langmuir and DubininRadushcevich adsorption theories. The energy of adsorption Zn2+ and Ba2+ onto modified TiO2 and unmodified TiO2 was calculated using Dubinin-Radushkevich equations, and was found to be 15.82 - 9.399 kJ/mol, which corresponds to the mechanism of physical adsorption. The application of Langmuir theory to experimental adsorption data gives high R2, close to unit. Separation factor RL indicates, that adsorption Zn2+ and Ba2+ onto modified TiO2 is very favorable. Modified mesoporous ТіО2 is very efficient adsorbent toward Zn2+ and Ba2+ cations from their individual solutions as well as from their mixture, and able to compete with the best world analogues.

A Fractal Approach To Adsorption on Heterogeneous Solids Surfaces. 2. Thermodynamic Analysis of Experimental Adsorption Data

2001 ◽  
Vol 105 (44) ◽  
pp. 10857-10866 ◽  
Author(s):  
Wladyslaw Rudzinski ◽  
Shyi-Long Lee ◽  
Tomasz Panczyk ◽  
Ching-Cher Sanders Yan
Keyword(s):  
Thermodynamic Analysis ◽  
Heterogeneous Solids ◽  
Experimental Adsorption ◽  
Fractal Approach ◽  
Adsorption Data

scholarly journals Adsorption of Sodium Cholate on Cationic Dextran Gels: Comparison of Isotherm Binding Models

2021 ◽  
Vol 57 (4) ◽  
pp. 181-192
Author(s):  
Magdalena Cristina Stanciu ◽  
Marieta Nichifor ◽  
Prisacaru Anca-Irina
Keyword(s):  
Bile Acid ◽  
Entire Range ◽  
Sodium Cholate ◽  
Equilibrium Analysis ◽  
Acid Salt ◽  
Nacl Solution ◽  
Experimental Adsorption ◽  
Binding Models ◽  
Adsorption Data ◽  
Dimethylammonium Chloride

Cationic dextran hydrogels having pendent 51-59 mol% N-alkyl-N,N-dimethylammonium chloride groups were synthesized and tested as adsorbents for sodium cholate. The bile acid salt sorption by these gels was evaluated by equilibrium analysis in water and 10 mM NaCl solution. The best adsorption results were obtained with amphiphilic dextran-based gels having two types of pendant ammonium chloride groups with different polarities. Experimental adsorption data for all polymers fitted good with Langmuir, Dubinin-Raduskevich and Temkin models over the entire range of ligand concentrations. The maximum experimental adsorption capacity of dextran sorbents for sodium cholate was in the range 850-1075 mg/g.

Tax maneuver in the oil industry: Provisional results and risks for further implementation

2020 ◽  
pp. 28-43
Author(s):  
A. S. Kaukin ◽  
E. М. Miller
Keyword(s):  
Oil Industry ◽  
Oil Products ◽  
Oil Refining ◽  
State Budget ◽  
Tax Rate ◽  
Oil Companies ◽  
Reform Plan ◽  
Alternative Variant ◽  
Calculation Results ◽  
The Cost

The paper analyzes the consequences of the abolition of the export duty on oil and oil products as a necessary step to stimulate energy efficiency of Russia’s economy and eliminate underdevelopment provoked by a long-term subsidizing of inefficient oil refining sector in Russia. The calculation results have shown that even taking into account several deviations from the planned scenarios of changing the parameters of tax regulation of the oil industry in 2014— 2019, the tax maneuver brought over 3.5 trillion rubles (in 2019 — 148 billion rubles) to the state budget in 2014—2017, mainly due to an increase in the base mineral extraction tax rate, and contributed to an increase in the depth of oil refining from 72% to 85%. In addition, the article analyzes possible risks associated with the current plan for reforming the taxation of the industry until 2024 and proposes an alternative that could level some of them. A comparative analysis of the effects of the tax maneuver under the current reform plan and the alternative variant suggests that the latter will allow to achieve a greater total budgetary effect in four years, reduce the cost of subsidizing domestic oil refining, increase the efficiency of Russian vertically integrated oil companies, and reduce the growth rate of oil products prices in the retail market.

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