scholarly journals Polyethyleneimine Supported Mesoporous Silica for CO2 Capture: Adsorption Kinetics and Degradation Problems

2015 ◽  
Vol 11 (2) ◽  
Keyword(s):  
Mesoporous Silica ◽  
Adsorption Kinetics ◽  
Co2 Capture ◽  
Co2 Adsorption ◽  
Second Order ◽  
Order Model ◽  
Capture Process ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order ◽  
Second Order Model

Polyethyleneimine supported mesoporous silica (PEI-MPS) has widely been investigated as solid sorbents for CO2 adsorption in laboratory. However, the adsorption kinetics of CO2 on this sorbent is still a disputed problem and the sorbent degradation could be a cause that hinders the sorbent from industrial application. In this study, the PEI-MPS sorbent was prepared by impregnating PEI onto mesoporous silica and then the adsorption kinetics was investigated using the pseudofirst order model, pseudo-second order model and intraparticle diffusion model. Results indicated that the CO2 adsorption kinetics on the sorbent occurred in a 2 stage process. In early stage, it is well fitted by the pseudo-first order model, but in later stage, it is well fitted by the intraparticle diffusion model. The pseudo second-order model proved to be the most suitable one to describe the adsorption of CO2 on the sorbent for the whole adsorption period with less than 5% absolute deviation. The sorbent with a CO2 adsorption capacity of 144.9 mg/g was calculated based on the fitting of the pseudo- second order model. The major degradation issues and their potential effects on the CO2 capture process were also discussed. The degradation significantly impacts on the performance and efficiency of CO2 capture process. The chemical degradation, however, can be considerably minimized by humidification.

scholarly journals Adsorption of cationic dye onto Moroccan natural rock

2019 ◽  
Vol 9 (1) ◽  
pp. 37-44
Author(s):  
Amira AM ◽  
Fatima Ouzidan ◽  
Tarik Ainane ◽  
Mohamed Talbi ◽  
M'hammed El Kouali
Keyword(s):  
Adsorption Kinetics ◽  
Diffusion Mechanism ◽  
Elimination Rate ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Natural Rock ◽  
Pseudo Second Order ◽  
Second Order Model

This paper evaluates the ability of a natural rock found in Morocco to remove the pollutant properties of methylene blue (MB) dye. In this regard, the experiments were conceived to test the hypothesis that the rock native of the country’s region of Khenifra can be used as a new abundant adsorbent to remove cationic dyes from water through the adsorption technique in order to avoid extra cost and contribute to the valorization of this material. For this, several factors such as pH of the solution, granulometry, mass of adsorbent, initial dye concentration and stirring rate were tested. The adsorption kinetics process was tested through three models, namely, the pseudo-first-order model, pseudo-second-order model and the intraparticle diffusion model, to predict which type of adsorption is best suited in the removal of dye pollution. The batch study proves that only the granulometry (G ≤ 63µm = 91%, G ≤ 80µm = 88.4% and G ≤ 100µm=70.7%) and the adsorbent mass (the more the mass of the adsorbent increases the more the elimination is achieved) can influence the elimination rate of our rock. Meanwhile, the data of the adsorption kinetics test show that the experimental adsorption could be described by the mechanism of the pseudo-second-order model (correlation coefficients near the unit ‘R 2 = 0.99’ ), confirming chemical sorption as a rate-limiting step of the intraparticle diffusion mechanism. According to the results of this study, the rock collected from the area of Khenifra can be used as a new and efficient adsorbent in the field of wastewater treatment.

Adsorption Kinetics of Pb2+ Ions Using Chitosan Nanoparticles

2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu
Keyword(s):  
Adsorption Kinetics ◽  
Chitosan Nanoparticles ◽  
Second Order ◽  
Isotherm Model ◽  
Order Model ◽  
Adsorption Characteristics ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Model

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.

Adsorption Kinetics of Zn(II) from Aqueous Solutions onto Epichlorohydrin Crosslinked Chitosan

2012 ◽  
Vol 463-464 ◽  
pp. 7-11 ◽  
Author(s):  
Ming Yan Dang ◽  
Hong Min Guo ◽  
Yan Kun Tan
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Crosslinking Agent ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Crosslinked Chitosan ◽  
Kinetics Of ◽  
Second Order Model

Chitosan was crosslinked using epichlorohydrin as crosslinking agent to prepare crosslinked chitosan which was used as an adsorbent for the removal of Zn(II) from aqueous solutions. The adsorption prosperities of Zn(II) on crosslinked chitosan were studied, including the influence of pH value and the adsorption kinetics. The kinetics of adsorption was discussed using two kinetic models, the pseudo first-order and the pseudo second-order model. Results reveal that the crosslinked chitosan is suitable as adsorbent to remove Zn(II) from dilute solution. The rate parameters for the Zn(II) by crosslinked chitosan were also determined. It was shown that the adsorption kinetics of Zn(II) could be best described by the pseudo second-order model and the adsorption process may involve a physical adsorption.

scholarly journals Study of Fluoride Affinity by Zirconium Impregnated Walnut Shell Carbon in Aqueous Phase: Kinetic and Isotherm Evaluation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Rajan ◽  
G. Alagumuthu
Keyword(s):  
Ph Value ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Walnut Shell ◽  
Fluoride Removal ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Bicarbonate Ions ◽  
Pseudo Second Order ◽  
Second Order Model

This paper examines the kinetics of fluoride removal from water by the adsorbent zirconium-impregnated walnut-shell carbon (ZIWSC), exploring the mechanisms involved. The dependence of the adsorption of fluoride on the pH of the solution has been studied to achieve the optimum pH value and a better understanding of the adsorption mechanism. The presence of bicarbonate ions in aqueous solution was found to affect the fluoride removal indicating that these anions compete with the sorption of fluoride on adsorbents. The kinetic profile has been modeled using pseudo-first-order model, pseudo-second-order model, and intraparticle diffusion model. The kinetic sorption profiles offered excellent fit with pseudo-second-order model. Adsorption isotherms have been modeled by Langmuir, Freundlich, and Temkin equations, and their constants were determined. The equilibrium adsorption data were fitted reasonably well for Freundlich isotherm model. XRD and SEM patterns of the ZIWSC were recorded to get better insight into the mechanism of adsorption process.

scholarly journals Kinetic and Thermodynamic Studies on the Phosphate Adsorption Removal by Dolomite Mineral

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoli Yuan ◽  
Wentang Xia ◽  
Juan An ◽  
Jianguo Yin ◽  
Xuejiao Zhou ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Removal Rate ◽  
Second Order ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Thermodynamic Studies ◽  
Pseudo Second Order ◽  
Second Order Model

The efficiency of dolomite to remove phosphate from aqueous solutions was investigated. The experimental results showed that the removal of phosphate by dolomite was rapid (the removal rate over 95% in 60 min) when the initial phosphate concentration is at the range of 10–50 mg/L. Several kinetic models including intraparticle diffusion model, pseudo-first-order model, Elovich model, and pseudo-second-order model were employed to evaluate the kinetics data of phosphate adsorption onto dolomite and pseudo-second-order model was recommended to describe the adsorption kinetics characteristics. Further analysis of the adsorption kinetics indicated that the phosphate removal process was mainly controlled by chemical bonding or chemisorption. Moreover, both Freundlich and Langmuir adsorption isotherms were used to evaluate the experimental data. The results indicated that Langmuir isotherm was more suitable to describe the adsorption characteristics of dolomite. Maximum adsorption capacity of phosphate by dolomite was found to be 4.76 mg phosphorous/g dolomite. Thermodynamic studies showed that phosphate adsorption was exothermic. The study implies that dolomite is an excellent low cost material for phosphate removal in wastewater treatment process.

Electrosorption of Methylene Blue from Aqueous Solution on Graphene-Titanium Electrode: Adsorption Kinetics Studies

2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Dan Wu ◽  
Yaxiu Zhao ◽  
Qiang Liu ◽  
Chein-Chi Chang ◽  
Wei Hou
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Kinetics ◽  
Graphene Film ◽  
Titanium Substrate ◽  
Second Order ◽  
Applied Potential ◽  
Order Model ◽  
Pseudo Second Order ◽  
Second Order Model

Abstract A graphene film deposited on titanium substrate was successfully prepared by a facile solution evaporation method, as electrode exhibiting superior electrosorption property toward methylene blue (MB) from aqueous solution. The fabricated graphene film on titanium substrate was characterized in detail by scanning electron microscopy (SEM) and FTIR techniques. As electrode (GTE) for electrosorption of MB, some experimental parameters, such as applied potential, concentration of electrolyte, solution initial pH and temperature, were systematically investigated and discussed. The experimental results demonstrated that the maximum adsorption capacity using GTE can reach 86.06 mg· g−1 under the optimized conditions of −600 mV of applied potential, pH of 7.5, 293 K and 0.01 mg· L−1 Na2SO4 solution, which is 1.40 times of that obtained under open circuit condition in 10 mg· L−1 MB solution. The adsorption isotherm of MB on GTE was analyzed with Langmuir and Freundlich isotherm equations, Pseudo-first-order model, pseudo-second-order model, and intra-particle diffusion model were applied to depict the adsorption kinetics process. The electrosorption of MB preferably fitted Langmuir isotherm, indicating a single-layer adsorption of MB molecules on graphene film followed pseudo-second-order model. Moreover the electrosorption of MB on GTE was found to be spontaneous and endothermic process. This work would be helpful to design and fabricate high performance carbon-based electrodes for high efficiency electrosorption treatment of dye wastewaters.

scholarly journals Eco-Friendly Materials Obtained by Fly Ash Sulphuric Activation for Cadmium Ions Removal

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3584
Author(s):  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Tiberiu Roman ◽  
Marieta Porcescu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Sulphuric Acid ◽  
Metal Ion ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Acid Activation ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order ◽  
Second Order Model

Wastes are the sustainable sources of raw materials for the synthesis of new adsorbent materials. This study has as objectives the advanced capitalization of fly ash, by sulphuric acid activation methods, and testing of synthesized materials for heavy metals removal. Based on the previous studies, the synthesis parameters were 1/3 s/L ratio, 80 °C temperature and 10% diluted sulphuric acid, which permitted the synthesis of an eco-friendly adsorbent. The prepared adsorbent was characterized through SEM, EDX, FTIR, XRD and BET methods. Adsorption studies were carried out for the removal of Cd2+ ions, recognized as ions dangerous for the environment. The effects of adsorbent dose, contact time and metal ion concentrations were studied. The data were tested in terms of Langmuir and Freundlich isotherm and it was found that the Langmuir isotherm fitted the adsorption with a maximum adsorption capacity of 28.09 mg/g. Kinetic data were evaluated with the pseudo-first-order model, the pseudo-second-order model and the intraparticle diffusion model. The kinetics of cadmium adsorption into eco-friendly material was described with the pseudo-second-order model, which indicated the chemisorption mechanism.

scholarly journals Adsorption kinetics of Direct Black 38 on nitrogen-doped TiO2

2014 ◽  
Vol 16 (4) ◽  
pp. 690-698 ◽  
Keyword(s):  
Adsorption Kinetics ◽  
Kinetic Studies ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Nitrogen Doped ◽  
Calcination Temperatures ◽  
Three Samples ◽  
Pseudo Second Order ◽  
Second Order Model

<div> <p>In this work, three samples of nitrogen-doped TiO<sub>2 </sub>prepared at different calcination temperatures (400, 450 and 500 &deg;C) were applied for the adsorption of Direct Black 38. Kinetic studies about the adsorption of Direct Black 38 on nitrogen-doped TiO<sub>2 </sub>were performed under different initial dye concentrations<br /> (75-175 mg l<sup>-1</sup>). Pseudo-first and pseudo-second order models were fitted with the experimental data. The results revealed that nitrogen-doped TiO<sub>2 </sub>synthesized at 400 &deg;C presented the more adequate characteristics for adsorption purposes, such as specific surface area of 151 m<sup>2</sup> g<sup>-1</sup>. The adsorption kinetics agreed with the pseudo-second order model, at initial dye concentrations from 75 to 175 mg l<sup>-1</sup>. The maximum adsorption capacity predicted by the pseudo-second order model was 138.3 mg g<sup>-1</sup>, and was obtained using nitrogen-doped TiO<sub>2</sub> synthesized at 400 &deg;C. In summary, these results revealed that nitrogen-doped TiO<sub>2</sub> is a good material for the removal Direct Black 38 from aqueous solutions by adsorption.&nbsp;</p> </div> <p>&nbsp;</p>

Polyaniline/ZnO nanocomposites for the removal of methyl orange dye from waste water

2018 ◽  
Vol 32 (19) ◽  
pp. 1840085 ◽  
Author(s):  
Neha V. Nerkar ◽  
Subhash B. Kondawar ◽  
Snehal Kargirwar Brahme ◽  
Yun Hae Kim
Keyword(s):  
Waste Water ◽  
Methyl Orange ◽  
Adsorption Mechanism ◽  
Second Order ◽  
Pure Pani ◽  
Time Interval ◽  
Order Model ◽  
Vis Spectroscopy ◽  
Pseudo Second Order ◽  
Second Order Model

In this paper, we report the safe removal of methyl orange (MO) dye from aqueous solution using chemical interaction of dye molecule with polyaniline/zinc oxide (PANI/ZnO) nanocomposite. PANI/ZnO nanocomposite has been prepared by in situ polymerization. PANI/ZnO nanocomposite was found to be the best promising candidate for adsorption of dyes due to more porosities compared to that of pure PANI. In the present investigation, PANI/ZnO nanocomposite was mixed in a solution of MO dye and used for adsorption process. Color removal was studied using UV-Vis spectroscopy and the spectra were recorded for specific time interval and validation of kinetic model has been applied. Absorbance of PANI/ZnO nanocomposite was found to be increased as compared to that of pure ZnO nanoparticles and pure PANI due to synergistic effect. Comparatively, the removal of dye was also found to be more by using PANI/ZnO nanocomposites. In order to evaluate kinetic mechanism the pseudo-first-order model, pseudo-second-order model and intraparticle diffusion models were verified by the linear equation analysis. Adsorption mechanism of pseudo-second-order model was systematically explained for removal of dye using PANI/ZnO nanocomposite. The results clearly demonstrated that the adsorption mechanism gives very novel and green method of removal of hazardous dyes from waste water.

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