Adsorption of cadmium and copper onto natural clay: isotherm, kinetic and thermodynamic studies

doi:10.30955/gnj.002352

Cited by 21 publications

(2 citation statements)

References 39 publications

(58 reference statements)

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“…However, theory indicates that adsorption is a process influenced by mass and heat transfer [EL ASS 2018], where the surface area, and therefore the particle diameter, play an essential role in the provision of active sites. Temperature affects the spontaneity of the process, favouring the adsorption or desorption of the metal.…”

Section: Effect Of Temperature and Particle Diametermentioning

confidence: 99%

Journal of Water and Land Development

2022

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Contamination of water bodies by heavy metals is a continuously growing environmental issue. High concentrations of mercury (Hg) in river waters are a recognized environmental problem, because it is one of the most toxic heavy metal ions as it causes damage to the central nervous system. Its negative impact has led to the development of different methods for the treatment of effluents contaminated with Hg(II). The aim of this article is to evaluate the use of coffee (Coffea arabica) residues as adsorbent of Mercury in an aqueous solution. Four kinetic models, including intraparticle diffusion, pseudo-first-order, pseudo-second-order, and Elovich kinetic models were applied to explore the internal mechanism of mercury adsorption. Results indicate that the pseudo-first-order and pseudo-second-order models could accurately describe the adsorption process. It means that chemical adsorption play an important role in the adsorption of mercury by activated carbon. Meanwhile, the external mass transfer process is more effective in controlling the activated carbon mercury adsorption according to the fitting result of the pseudo-first-order model. The fitting to Langmuir's model suggested that the material surface is energetically homogeneous. The technique of contaminated biomass encapsulation proved to be safe for short-term disposal when metal recovery is not desired.

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Section: Effect Of Temperature and Particle Diametermentioning

confidence: 99%

Journal of Water and Land Development

2022

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“…Adjusting the adsorption kinetics of Ni (II) and Pb (II) on the lemon peel suggests that the adsorption is carried out in two steps. Firstly, the metal diffuses through the solution until it reaches the external surface of the bio-adsorbent, so there would be a rapid adsorption rate during the first minutes of the process and micro-precipitates would form in the external contact area (Figures 3b and 3c) [50], [51]. In the second one, there would be the process of diffusion of Lead and Nickel through the pores of the adsorbent material, so that the process would take place in multiple internal active sites until saturation is reached, promoting the formation of complexes.…”

Section: Modelling Of Adsorption Kineticsmentioning

confidence: 99%

Adsorption in a binary system of Pb (II) and Ni (II) using lemon peels

Tovar

Sierra-Ardila

Meza-Acuña

et al. 2020

Rev.Fac.Ing.Univ.Antioquia

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The elimination of pollutants in water sources is a widely studied issue with the purpose of preserving the environment. In this work, the use of lemon peel (citrus lemon) as a bio-sorbent in the removal of Pb (II) and Ni (II) is studied, varying the temperature, adsorbent dose, and particle size. The materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analysis, to determine the bio adsorbent’s physicochemical properties. FTIR and EDS techniques confirmed the precipitation of ions on the adsorbent after the adsorption process. It was found that the optimal conditions according to the Response Surface Methodology (RSM) are: particle size for Ni (II) of 1 and 0.355 mm, adsorbent dose 0.077 g and 0.117 g, and temperatures of 34 and 45 ºC, for Pb (II) and Ni (II), respectively. The results reported that the Dubinin-Radushkevich isotherm and the pseudo-second-order model are more in line with the experimental data, suggesting that the adsorption process is driven by physisorption and occurs in multilayers. Thermodynamic parameters suggest that the process is exothermic for Ni (II) and endothermic for Pb (II), and irreversible. The binary study showed that there is no competition for active sites between the ions.

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