Thermodynamics of Pb2+ and Ni2+ adsorption onto natural bentonite from aqueous solutions

Donat, Ramazan; Akdoğan, Abdullah; Erdem, Emre; Çetişli, Halil

doi:10.1016/j.jcis.2005.01.045

Cited by 380 publications

(207 citation statements)

References 26 publications

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“…The positive value of ΔS 0 indicated that the adsorption process was irreversible and random at the solid/liquid interface during the sorption of malachite green onto the wood adsorbent. In addition, the positive value of ΔS 0 suggested some structural change of malachite green and the wood adsorbent (Gupta, 1998) and favored complexion and sorption stability (Donat et al 2005). Similar results were also observed on carbon prepared from Arundo donax root ) and de-oiled soya (Mittal et al 2005), bentonite (Bulut et al 2008) and hen feathers (Mittal, 2006).…”

Section: Thermodynamic Studiessupporting

confidence: 68%

Removal of malachite green from water by Firmiana simplex wood fiber

Jian¹,

Xiangliang²,

Zhang³

et al. 2009

Electro Journal of Biotech

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This study shows that wood fiber of Phoenix tree (Firmiana simplex) is an effective adsorbent for malachite green (MG). MG sorption behavior onto the wood adsorbent was investigated in this study. Basic condition was favorable for MG adsorption to the adsorbent. The pseudo second order equation well described MG adsorption onto the wood adsorbent. The Freundlich Isotherm could describe the sorption data. The positive value of ΔH 0 showed that adsorption of malachite green onto the wood adsorbent was endothermic. The negative values of ΔG at various temperatures indicate the spontaneous nature of the adsorption process.

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Section: Thermodynamic Studiessupporting

confidence: 68%

Removal of malachite green from water by Firmiana simplex wood fiber

Jian¹,

Xiangliang²,

Zhang³

et al. 2009

Electro Journal of Biotech

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“…e D-R isotherm model is more general than Langmuir isotherm as it rejects the homogenous surface or constant sorption potential. As illustrated in Table 8, the values of are less than 8.00 kJ/mol, this indicates that physical forces affect the sorption [28]. It is interesting to note that the difference of max derived from the Langmuir and / derived from D-R models is quite large.…”

Section: Metal Sorption Studies Onmentioning

confidence: 89%

Sorption of Uranium(VI) and Thorium(IV) by Jordanian Bentonite

Khalili

Salameh

Shaybe

2012

Journal of Chemistry

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Puri�cation of raw bentonite was done to remove quartz. is includes mixing the raw bentonite with water and then centrifuge it at �50 rpm; this process is repeated until white puri�ed bentonite is obtained. �RD, �RF, FTIR, and SEM techniques will be used for the characterization of puri�ed bentonite. e sorption behavior of puri�ed Jordanian bentonite towards UO 2 2+and  4+ metal ions in aqueous solutions was studied by batch experiment as a function of pH, contact time, temperature, and column techniques at 25.0 ∘ C and pH = 3. e highest rate of metal ions uptake was observed aer 18 h of shaking, and the uptake has increased with increasing pH and reached a maximum at pH = 3. Bentonite has shown high metal ion uptake capacity toward uranium(VI) than thorium(IV). Sorption data were evaluated according to the pseudo-second-order reaction kinetic. Sorption isotherms were studied at temperatures 25.0 ∘ C, 35.0 ∘ C, and 45.0 ∘ C. e Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) sorption models equations were applied and the proper constants were derived. It was found that the sorption process is enthalpy driven for uranium(VI) and thorium(IV). Recovery of uranium(VI) and thorium(IV) ions aer sorption was carried out by treatment of the loaded bentonite with different concentrations of HNO 3 1.0 M, 0.5 M, 0.1 M, and 0.01 M. e best percent recovery for uranium(VI) and thorium(IV) was obtained when 1.0 M HNO 3 was used.

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“…Thermodynamic parameters [31,32], such as free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS), were estimated using the following equations. D represents the distribution coefficient (L/g), which is equal to the absorption equilibrium constant at the solid/liquid phase, and is shown as a function of the temperature.…”

Section: Thermodynamics Of the Adsorptionmentioning

confidence: 99%