Enhanced selective adsorption desulfurization on CO2 and steam treated activated carbons: Equilibria and kinetics

2020 ◽  
Vol 379 ◽  
pp. 122356 ◽  
Author(s):  
Diana Iruretagoyena ◽  
Kagiso Bikane ◽  
Nixon Sunny ◽  
Huiqiang Lu ◽  
Sergei G. Kazarian ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Selective Adsorption ◽  
Adsorption Desulfurization

scholarly journals An alternative low-cost adsorbent for gold recovery from cyanide-leached liquors: Adsorption isotherm and kinetic studies

2018 ◽  
Vol 37 (1-2) ◽  
pp. 3-23 ◽  
Author(s):  
Refiloe Tsolele ◽  
Fanyana Moses Mtunzi ◽  
Michael John Klink ◽  
Vusumzi Emmanuel Pakade
Keyword(s):  
Activated Carbons ◽  
Selective Adsorption ◽  
Low Cost ◽  
Kinetic Studies ◽  
Agitation Speed ◽  
Gold Recovery ◽  
Attractive Alternative ◽  
Solution Ph ◽  
Initial Concentration ◽  
Modified Activated Carbons

Pristine Macadamia nutshell-based activated carbons were chemically oxidized with different concentrations of H3PO4 and HNO3 to increase their surface adsorption properties and further explore if they could be an attractive alternative low-cost adsorbent for gold recovery from cyanide-leached liquors. The modified activated carbons were labeled MACN20, MACN40 and MACN55 to signify the materials prepared from 20%, 40% and 55% (v/v) HNO3, respectively. Similar nomenclature was followed for H3PO4-modified activated carbons. Brunauer-Emmet-Teller, scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, elemental analysis and X-ray diffraction spectroscopy were used to characterize the prepared activated carbons. The physical properties were attained through determining attrition, ash content, volatile matter and moisture content of all the activated carbons. Various parameters that affect selective adsorption such as the effect of initial concentration, time, agitation speed, interfering species and the dose of the adsorbent were investigated. Optimal parameters for gold ion adsorption were as follows: solution pH, 10; contact time, 6 h; agitation speed, 150 r/min; sorbent amount, 4 g and initial concentration, 5.5 mg/L. The observed selectivity order was not the same for all the adsorbents, but the adsorption of gold was found to be mostly influenced in the presence of nickel and least influenced by copper. MACN55 was found to be the most efficient adsorbent with 74% of gold adsorption from a real-world sample and displayed a similar performance to coconut-based activated carbons.

SURFACE ALTERATION OF ACTIVATED CARBON FOR DETOXIFICATION OF COPPER (II) FROM INDUSTRIAL EFFLUENTS

2013 ◽  
Vol 20 (02) ◽  
pp. 1350021
Author(s):  
SADAF BHUTTO ◽  
M. NASIRUDDIN KHAN
Keyword(s):  
Activated Carbons ◽  
Selective Adsorption ◽  
Low Cost ◽  
Industrial Effluents ◽  
Copper Adsorption ◽  
Adsorption Capacities ◽  
Surface Alteration ◽  
Equilibrium Data ◽  
Modified Activated Carbons ◽  
Acetic Acids

The low-cost modified activated carbons were prepared from Thar and Lakhra (Pakistan) coals by activation with sulfuric acid and further modified with citric, tartaric and acetic acids for the selective adsorption of Cu(II) from aqueous solution. The original carbon obtained from activated Thar and Lakhra coals at pH 3.0 displayed significant adsorption capacity for lead and insignificant capacity values (0.880 and 0.830 mg⋅g-1) for copper. However, after modification with citric, tartaric and acetic acid the copper adsorption capacities enhanced in the range of 5.56–21.85 and 6.05–44.61 times, respectively. The Langmuir, Freundlich and Temkin adsorption isotherms were used to elucidate the observed sorption phenomena. The isotherm equilibrium data was well fitted by the Langmuir and sufficiently fitted to the Freundlich models. The calculated thermodynamic parameters such as change in Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) inferred that the investigated adsorption was spontaneous and endothermic in nature. Based on the results, it was concluded that the surface alteration with citric and tartaric acid, Thar and Lakhra activated carbons had significant potential for selective removal of copper(II) from industrial wastewater.

SO and NO selective adsorption properties of coal-based activated carbons

Fuel ◽  
2005 ◽  
Vol 84 (4) ◽  
pp. 461-465 ◽  
Author(s):  
T QIANG ◽  
Z ZHIGANG ◽  
Z WENPEI ◽  
C ZIDONG
Keyword(s):  
Activated Carbons ◽  
Selective Adsorption ◽  
Adsorption Properties

scholarly journals Synthesis of highly active Cu(I)-Y(III)-Y zeolite and its selective adsorption desulfurization performance in presence of xylene isomers

2020 ◽  
Author(s):  
Bo-Long Jiang ◽  
Nan Jiang ◽  
You-Xin Chang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Selective Adsorption ◽  
Sulfur Removal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Active ◽  
Adsorption Desulfurization ◽  
Para Xylene ◽  
Xylene Isomers ◽  
Fluorescence Spectrometer

Abstract Abstract A bimetal-exchanged NaY zeolite (Cu(I)-Y(III)-Y) with a desirable adsorptive desulfurization (ADS) performance was prepared and characterized by means of X-ray diffraction, specific surface area measurements, X-ray fluorescence spectrometer, X-ray photoelectron spectroscopy, thermal gravity analysis and Fourier transform infrared spectroscopy. The effect of Y(III) ions on ADS in the presence of the xylenes was investigated. Results indicated that the ADS performance of Y(III)-Y is higher than that of most reported CeY. The Y(III)-based Cu(I)-Y(III)-Y demonstrated the higher breakthrough loading than those of reported Ce(III)/Ce(IV)-based transition metal Y zeolites, showing that Y(III) ions play a promoting role in improving the ADS selectivity. For Cu(I)-Y(III)-Y, a new strong S-M interaction (S stands for sulfur, while M stands for metal) active site was formed, which might be caused by the synergistic effect between Cu(I) and Y(III). The Cu(I)-Y(III)-Y, which combined the advantages of Cu(I)-Y and Y(III)-Y, is a kind of promising adsorbent. The breakthrough loading decreased in the order of Cu(I)-Y(III)-Y > Y(III)-Y > Cu(I)-Y, and the effect of xylene isomers on the sulfur removal was in the order of ortho-xylene > meta-xylene > para-xylene, which exhibited the same trend with the bond order of xylenes.

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