Application of Dubinin–Radushkevich isotherm model at the solid/solution interface: A theoretical analysis

Hu, Qili; Zhang, Zhenya

doi:10.1016/j.molliq.2019.01.005

Cited by 411 publications

(135 citation statements)

References 21 publications

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“…The Langmuir [ 52 ] (Equation (2)), Freundlich [ 53 ] (Equation (3)), Dubinin-Astakhov (D-A) [ 54 ] (Equation (4)), Dubinin-Radushkevich (D-R) [ 55 ] (Equation (5)), and Sips [ 30 ] (Equation (6)) equations were adjusted to the adsorption isotherms to infer surface properties of the natural and acidified bentonite with anionic and cationic dyes. The equations of the isothermic models mentioned are summarized below:

where for the Langmuir equation,

(mg/g) is the maximum adsorption capacity, C e (mg/g) is the equilibrium concentration, and K L (L/mg) is the Langmuir constant.…”

Section: Methodsmentioning

confidence: 99%

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

et al. 2020

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The efficiency of acid treatment on natural calcium bentonite (natural bentonite) for anionic dye adsorption was investigated using methyl orange (MO) as a probe. Additionally, adsorption experiments were accomplished between the natural bentonite, acidified bentonite, and a cationic dye (methylene blue, MB). Acid functionalization in natural bentonite (RF) was carried out with HCl and H2SO4 acids (RF1 and RF2, respectively). The samples were characterized by chemical analysis, mineralogy, particle size, and thermal behavior with the associated mass losses. The adsorption efficiency of MO and MB dyes was investigated by the effects of the initial concentration of adsorbate (Ci) and the contact time (tc). The acid treatment was efficient for increasing the adsorption capacity of the anionic dye, and the Qmaxexp values measured were 2.2 mg/g, 67.4 mg/g e 47.8 mg/g to RF, RF1 e RF2, respectively. On the other hand, the acid functionalization of bentonite did not significantly modify the MB dye adsorption. The Sips equation was the best fit for the adsorption isotherms. Thus, we found that the acid-functionalized bentonite increases the anionic dye adsorption by up to 8000%. The increased adsorptive capacity of acidified bentonite was explained in terms of electrostatic attraction between the clay surface and the dye molecule.

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where for the Langmuir equation,

(mg/g) is the maximum adsorption capacity, C e (mg/g) is the equilibrium concentration, and K L (L/mg) is the Langmuir constant.…”

Section: Methodsmentioning

confidence: 99%

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

et al. 2020

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“…The isotherms of samples had a classical type I-isotherm as IUPAC classified, characteristic of microporous materials. Relatively low pressure ( P / P 0 < 0.1), the adsorption isotherms showed a steep curve which indicated large adsorption potential in micropore (width, 2 nm) adsorption area [ 23 – 25 ]. This form implies the existence of porous carbon contained substantial proportion micropores.…”

Section: Resultsmentioning

confidence: 99%

Sisal xylem fibre-based activated carbon fibres for fuel adsorption: effect of thermal stabilization of diammonium phosphate

Deng

2020

R. Soc. open sci.

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Activated carbon fibres (ACFs) are considered as the next generation of activated carbon products. However, lack of structural diversity in pore structure and high prices of raw materials for ACFs has restrained the development of ACF materials. In this paper, a sisal-based activated carbon fibre (SACF) material was prepared from sisal wastes with a unique thermal stabilization treatment to maintain fibrous shapes of SACFs while dispersing in solutions, and the SACFs were prepared as raw fibre materials for fuel evaporation emissions controlling products. Experimental results of N 2 adsorption showed that SACF has a typical I-type adsorption isotherm, with specific surface area of SACF samples of approximately 1200 m 2 g −1 , and mainly microporous pore structure. Compared with commercial samples (specific surface area, 1841.29 m 2 g −1 ), the butane working capacities of SACF for advanced fuel evaporation emissions controlling product was 0.4 g/100 ml higher. Furthermore, two dynamic models, Thomas model and Clark model, were applied to adsorption breakthrough data, which showed excellent fit. And it indicated from the adsorption breakthrough curves and parameters of both models that the SACF has better performance in fuel adsorption and desorption process than the commercial samples.

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“…Table S4 (SI section) shows that the E values calculated for all metal ions are < 8 kJ mol −1 , suggesting that the adsorption of Cd II , Pb II , Cu II , Cr III , Ni II and Zn II on the surface of biochar is physical. 83,84 The high values of R 2 indicates that the data are also well adjusted to Sips isotherm model. When n = 1, this model tends to Langmuir model.…”

Section: Adsorption Isothermsmentioning

confidence: 93%

Combined Analytical Py-GC/MS, SEM, FTIR and 13C NMR for Investigating the Removal of Trace Metals from Aqueous Solutions by Biochar

Andrade¹,

Monteiro²,

Gontijo³

et al. 2020

J. Braz. Chem. Soc.

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In this study, the efficiency of biochar (BC) produced from sugarcane bagasse at different pyrolysis temperatures (300, 400, 500 and 600 °C) for simultaneous removal of Cd II , Pb II , Cu II , Cr III , Ni II and Zn II ions from aqueous solutions was assessed. All BC were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), 13 C nuclear magnetic resonance (13 C NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The effects of pyrolysis temperature, initial adsorbate concentration and adsorbent dosage on adorption capacity of BC were examined through batch experiments. The BC efficiency was also evaluated after a desorption cycle. The maximal adsorptions (Cd II : 51.50%, Cr III : 74.35%, Cu II : 91.18%, Ni II : 47.05%, Pb II : 96.17% and Zn II : 40.50%) were observed for BC produced at 500 °C, probably because of its higher porosity and presence of functional groups detected by SEM and FTIR. The maximum adsorption capacity for Cd II , Cr III , Cu II , Ni II and Zn II (ions fitted to Langmuir model) were 175, 303, 455, 156 and 128 μg g −1 , respectively. The predominance of phenolic groups observed in Py-GC-MS data may explain the high percentage of multi-element removal. Experimental data were best fitted to pseudo-second order, Sips and Freundlich models. The BC presented good removal results after a desorption cycle.

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Application of Dubinin–Radushkevich isotherm model at the solid/solution interface: A theoretical analysis

Cited by 411 publications

References 21 publications

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

Sisal xylem fibre-based activated carbon fibres for fuel adsorption: effect of thermal stabilization of diammonium phosphate

Combined Analytical Py-GC/MS, SEM, FTIR and 13C NMR for Investigating the Removal of Trace Metals from Aqueous Solutions by Biochar

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