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 FLY ASH MAGNETIC ADSORBENT FOR CADMIUM ION REMOVAL FROM AN AQUEOUS SOLUTION

2021 ◽  
Vol 185 (1) ◽  
pp. 42-50
Author(s):  
Gabriela BUEMA ◽  
Nicoleta LUPU ◽  
Horia CHIRIAC ◽  
Dumitru Daniel HEREA ◽  
Lidia FAVIER ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Adsorption Capacity ◽  
Second Order ◽  
Order Model ◽  
Cadmium Ion ◽  
Cadmium Ions ◽  
Ion Removal ◽  
Pseudo Second Order ◽  
Second Order Model

The fly ash generated from a Romanian power plant was used as a starting material in this study. The aim of the study was to obtain a low cost material based on the treatment of fly ash with Fe3O4 for utilization as an adsorbent for cadmium ion removal. The adsorbent that was synthesized was characterized using different techniques. The adsorption process was investigated by the batch technique at room temperature. The quantity of cadmium ion adsorbed was measured spectrophotometrically. The experimental data showed that the material can remove cadmium ions at all three working concentrations. The adsorption capacity increased with an increase in concentration, respectively contact time. The results were analyzed through two kinetic models: pseudo first order and pseudo second order. The kinetics results of cadmium adsorption onto a magnetic material are in good agreement with a pseudo second order model, with a maximum adsorption capacity of 4.03 mg/g, 6.73 mg/g, and 9.65 mg/g. Additionally, the pseudo second order model was linearized into its four types. The results indicated that the material obtained show the ability to remove cadmium ions from an aqueous solution.

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.

Use of papaya seeds as a biosorbent of methylene blue from aqueous solution

2013 ◽  
Vol 68 (2) ◽  
pp. 441-447 ◽  
Author(s):  
Diego S. Paz ◽  
Alexandre Baiotto ◽  
Marcio Schwaab ◽  
Marcio A. Mazutti ◽  
Mariana M. Bassaco ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Second Order ◽  
Adsorption Kinetic ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Papaya Seeds ◽  
Second Order Model

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2–12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin–Raduschkevich, Tempkin, Jovanovich, Redlich–Peterson, Sips, Toth and Radke–Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g–1. Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model.

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.

Adsorption of Cu(II) from Aqueous Solutions by Ammoniated Cotton Fiber

2016 ◽  
Vol 11 (4) ◽  
pp. 155892501601100
Author(s):  
Chuanfeng Zang ◽  
Yu Ren ◽  
Fangfang Wang ◽  
Hong Lin ◽  
Yuyue Chen
Keyword(s):  
Aqueous Solutions ◽  
Cotton Fiber ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Second Order ◽  
Order Model ◽  
Amine Content ◽  
Pseudo Second Order ◽  
Adsorption Amount ◽  
Second Order Model

This study describes the preparation of a novel chelating cotton fiber adsorbent, ammoniated cotton fiber (ACF), which was prepared by modifying cotton fiber with amino-HBP using glutaraldehyde as a cross-linking agent. This new adsorbent was characterized and analyzed for amine content, and by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The capacity of ACF to adsorb Cu(II) from aqueous solution was evaluated at different pHs, contact times and initial metal ion concentrations. The results showed that ACF was effective in removing of Cu(II) from aqueous solutions and the adsorption amount of Cu(II) reached 16.7374 mg g-1. The adsorption isotherm and kinetics were well fitted to the Langmuir model and the pseudo-second-order model, respectively. The adsorption amount calculated using the pseudo-second-order model was in good agreement with the experimental data.

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 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>

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.

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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