The Elovich equation as a predictor of lead and cadmium sorption rates on contaminant barrier minerals

Inyang, Hilary I.; Onwawoma, Adrianna; Bae, Sunyoung

doi:10.1016/j.still.2015.07.013

Cited by 101 publications

(49 citation statements)

References 38 publications

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“…Under these conditions, a graph of q t versus (lnt) shows a linear relationship with a slope of (1/β) and intercept of (1/β)ln(αβ) [26]. This equation was used by Inyang et al and Onwawoma et al, to describe the kinetics of adsorption of pollutants in natural adsorbents, prepared or modified, in which they found that the best behavior of the obtained data is given when applying this model [26]. This equation is also used to describe reaction mechanisms, such as solute diffusion in the solution or interface phase, surface activation, and deactivation.…”

Section: Elovich Modelmentioning

confidence: 97%

“…2.5. Kinetic Study of the CO 2 Adsorption Process at 0 • C and Atmospheric Pressure Rate laws are essential in any adsorption study because they provide an exact expression during the duration of the reaction [26]. The models used in the present study are described below.…”

Section: Infrared Spectroscopymentioning

confidence: 99%

“…where α is the initial adsorption rate of the Elovich equation (mmol g −1 s −1 ) and β is the model adsorption constant (g mmol −1 ) [26], which is related to the adsorption energy [33]. The Elovich equation can be linearized assuming that αβt >> 1 and that q = 0 at t = 0 [34] and that q = q t for time t = t t [35].…”

Section: Elovich Modelmentioning

confidence: 99%

“…The Elovich equation can be linearized assuming that αβt >> 1 and that q = 0 at t = 0 [34] and that q = q t for time t = t t [35]. Under these conditions, a graph of q t versus (lnt) shows a linear relationship with a slope of (1/β) and intercept of (1/β)ln(αβ) [26]. This equation was used by Inyang et al and Onwawoma et al, to describe the kinetics of adsorption of pollutants in natural adsorbents, prepared or modified, in which they found that the best behavior of the obtained data is given when applying this model [26].…”

Section: Elovich Modelmentioning

confidence: 99%

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Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Romero

Moreno–Piraján

Gutiérrez

2018

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In this work, aerogels were prepared using resorcinol-formaldehyde as a precursor in two synthetic routes, one basic and one acidic, to perform the adsorption of CO 2 at 0 • C and atmospheric pressure. Aerogels were Characterization by N 2 and CO 2 Physisorption, Raman Spectroscopy, Scanning Electron Microscopy, and Infrared Spectroscopy. In general, was found that aerogels have a polymeric, disordered, three-dimensional structure and have a microporous surface. Langmuir, Freundlich, Sips and Toth equilibrium models present a good data fit of CO 2 adsorption at relative pressure ranging between 1 × 10 −4 and 3 × 10 −2 . The diffusion intra-particle kinetic model explains the setps of this process; the Elovich model also showed a good fit, therefore, there are an energetic heterogeneity of the CO 2 superficial adsorption sites. The aerogel carbonized in basic medium at 1050 • C (ACB 1050) material was the best adsorbent of this pollutant, reaching an adsorption capacity of 6.43 mmol g −1 .Achieving economic and favorable separation of CO 2 from gas mixtures represents one of the main technological and environmental problems facing our society today [10]. The most studied post-combustion technology is chemical adsorption. Monoethanol amine (MEA) has been the chemical most used for this purpose. Alternative solvents, such as piperazine and ammonia, have also been proposed to achieve this objective [6]. The advantage of this method is the low partial pressure that is used because the CO 2 molecules are easily absorbed over liquids in flue gas streams [11]. The disadvantage is that the use of amine alkoxysilanes is very expensive [12], and the method requires high regeneration energy due to the large emission of combustion gases and the costs of repairing the process equipment [4]. Other common methods to achieve CO 2 sequestration include separation in membranes, cryogenic and biological methods, and physical adsorption [13].Capture and storage technology has been considered the best option to reduce carbon dioxide emissions from large sources, and particularly adsorption is considered a promising process to separate gas mixtures [14]. This process is inexpensive, requires less regeneration energy, is easy to handle, has fast kinetics, and has a high capacity of CO 2 adsorption and selectivity [4]. The adsorbents provide a high surface area, which is a fundamental parameter in this process. Among the different adsorbents, 13X zeolite has been investigated to adsorb CO 2 by oscillating the pressure [6]. It is generally recognized that CO 2 is physically adsorbed to activated carbon, mainly by condensation or liquefaction in pores with widths that are less than 1 nm [15]. The adsorption of this greenhouse gas in nanopore materials has also been investigated in zeolites exchanged with alkali metals, amino-modified and modified alkaline, mesoporous silicas, microporous polymers, carbons, and metalorganic structures [10]. It has also been established that the chemical properties of activated carbon play a relevant role in...

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Section: Elovich Modelmentioning

confidence: 97%

Section: Infrared Spectroscopymentioning

confidence: 99%

Section: Elovich Modelmentioning

confidence: 99%

Section: Elovich Modelmentioning

confidence: 99%

See 2 more Smart Citations

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Romero

Moreno–Piraján

Gutiérrez

2018

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“…Elovich equation is useful model that can describe in a semi-empirical equation (Inyang et al, 2016), which is given by equations (7 and 8):…”

Section: Kinetic Studiesmentioning

confidence: 99%

Investigation of Copper Removal from Aqueous Solution by Cement Kiln Dust as Industrial By-Product

2017

Alexandria Science Exchange Journal: An International Quarterly

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This study investigated the copper (Cu +2 ) removal from aqueous solution by cement kiln dust (CKD) as industrial by-product in cement manufacturing process. CKD was identified by Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and surface areas show the differences of physicochemical properties. Batch equilibrium experiments were carried out at 20, 25 and 30 o C with time intervals extended to 96 h to investigate the efficiency of the CKD in the removal of Cu +2 . CKD expressed high affinity for removal of Cu +2 and was not affected by temperature or time. The removal of Cu +2 was indicated by changes of FTIR and SEM images before and after sorption experiments. The kinetic data were evaluated by fractional power, Elovich, pseudo-first order and pseudo-second-order kinetic models. The kinetic studies demonstrated that rate of the removal followed pseudo-second-order kinetic model (r 2 =0.99). Thermodynamic parameters, the change of free energy (ΔG•), enthalpy (ΔH•) and entropy (ΔS • ) were calculated for predicting the nature of adsorption. The parameters showed that the process was feasible, spontaneous and exothermic under experiment conditions. Solubility equilibrium for various expected copper compounds was estimated and the solubility of copper in Cu-CKD system suggested to be controlled by Cu CO 3 precipitation under experiment condition. The results indicated that CKD can be used as a low cost and effective sorbent for copper ions from aqueous solutions.

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Triethanolamine‐modified montmorillonite clay as a new adsorbent for CO₂ capture: Characterization, adsorption, and RSM modeling

Godarziani

Penchah

Ghaemi

2022

J Chinese Chemical Soc

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In this study, CO 2 adsorption capacity was investigated by modified montmorillonite with triethanolamine due to its mechanical and chemical stability. The effect of operational parameters on CO 2 adsorption capacity including temperature, pressure, and percentage triethanolamine was studied in the range of 30-70 C and 1-9 bar and 10-30%wt., respectively. Isothermal, kinetic, and thermodynamic analyses were performed by conventional method under equilibrium conditions. According to the R 2 values from fitting the experimental data on the isothermal models, the Hill isotherm model was proposed for the unmodified and modified montmorillonite adsorbent. The results showed that the Elovich kinetic model provides the best fit for CO 2 adsorption data for montmorillonite and triethanolamine-modified montmorillonite. In the study of thermodynamic models, the positive slope of the Ln (K d ) diagram against 1/T indicates the thermal conductivity of the surface adsorption process. Optimal operating parameters were determined to obtain the highest adsorption capacity using the Design Expert software. For montmorillonite, the adsorption capacity obtained 219.86 mg/g at a temperature of 40 C and pressure of 7 bar, and for modified montmorillonite with triethanolamine, the optimal conditions for the input variables were 40 C, 7 bar, and 18.36%wt., respectively, and the adsorption capacity obtained was 248.55 mg/g.

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The Elovich equation as a predictor of lead and cadmium sorption rates on contaminant barrier minerals

Cited by 101 publications

References 38 publications

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Investigation of Copper Removal from Aqueous Solution by Cement Kiln Dust as Industrial By-Product

Triethanolamine‐modified montmorillonite clay as a new adsorbent for CO₂ capture: Characterization, adsorption, and RSM modeling

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The Elovich equation as a predictor of lead and cadmium sorption rates on contaminant barrier minerals

Cited by 101 publications

References 38 publications

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Investigation of Copper Removal from Aqueous Solution by Cement Kiln Dust as Industrial By-Product

Triethanolamine‐modified montmorillonite clay as a new adsorbent for CO2 capture: Characterization, adsorption, and RSM modeling

Contact Info

Product

Resources

About

Triethanolamine‐modified montmorillonite clay as a new adsorbent for CO₂ capture: Characterization, adsorption, and RSM modeling