scholarly journals Studying Ni(II) Adsorption of Magnetite/Graphene Oxide/Chitosan Nanocomposite

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Luyen T. Tran ◽  
Hoang V. Tran ◽  
Thu D. Le ◽  
Giang L. Bach ◽  
Lam D. Tran

In this paper, Fe3O4/graphene oxide/chitosan (FGC) nanocomposite was synthesized using coprecipitation method for application to removal of nickel ion (Ni(II)) from aqueous solution by adsorption process. To determine residue Ni(II) ions concentration in aqueous solution after adsorption process, we have used UV-Vis spectrophotometric method, which is an effective and exact method for Ni(II) monitoring at low level by using dimethylglyoxime (DMG) as a complex reagent with Ni(II), which has a specific adsorption peak at the wavelength of 550 nm on UV-Vis spectra. A number of factors that influence Ni(II) ions adsorption capacity of FGC nanocomposite such as contact time, adsorption temperature, and adsorbent dosage were investigated. Results showed that the adsorption equilibrium is established after 70 minutes with the adsorbent dosage of 0.01 g.mL−1 at 30°C (the room temperature). The thermodynamic and kinetic parameters of this adsorption including free enthalpy change (∆G0), enthalpy change (∆H0), entropy change (∆S0), and reaction order with respect to Ni(II) ions were also determined. The Ni(II) ions adsorption equilibrium data are fitted well to the Langmuir isotherm and the maximum monolayer capacity (qmax) is 12.24 mg.g−1. Moreover, the FGC adsorbent can be recovered by an external magnet; in addition, it can be regenerated. The reusability of FGC was tested and results showed that 83.08% of removal efficiency was obtained after 3 cycles. The synthesized FGC nanocomposite with many advantages is a promising material for removal of heavy metal ions from aqueous solution to clean up the environment.

2014 ◽  
Vol 894 ◽  
pp. 121-124 ◽  
Author(s):  
Yan Qiang Jian ◽  
Ming Yu Li ◽  
Qing Xuan Zeng

A chelating ion exchange fiber containing thioureido groups for the removal of Cr (VI) has been prepared from chloramethylated styrene grafted polypropylene fiber (2.96 mmol/g Cl) reacted with thiourea, batch adsorption experiments are adopted to investigate its adsorption equilibrium properties, Adsorption isotherms at various temperatures were obtained. Langmuir linear equation model can well describe the adsorption equilibrium data suggesting that the adsorption process involves both chemisorption and physisorption. The values of thermodynamic parameters, including ΔH, ΔGand ΔS, indicate that the adsorption of Cr (VI) is a spontaneous, entropy-driven and endothermic process.


2013 ◽  
Vol 3 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Papita Das Saha ◽  
Jaya Srivastava ◽  
Shamik Chowdhury

The efficacy of seashells as a new adsorbent for removal of phenol from aqueous solutions was studied by performing batch equilibrium tests under different operating parameters such as solution pH, adsorbent dose, initial phenol concentration, and temperature. The phenol removal efficiency remained unaffected when the initial pH of the phenol solution was in the range of 3–8. The amount of phenol adsorbed increased with increasing initial phenol concentration while it decreased with increasing temperature. The adsorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer adsorption capacity of 175.27 mg g−1 at pH 4.0, initial phenol concentration = 50 mg L−1, adsorbent dose = 2 g and temperature = 293 K. Analysis of kinetic data showed that the adsorption process followed pseudo-second-order kinetics. Activation energy of the adsorption process, calculated using the Arrhenius equation, was found to be 51.38 kJ mol−1, suggesting that adsorption of phenol onto seashells involved chemical ion-exchange. The numerical value of the thermodynamic parameters (ΔG0, ΔH0 and ΔS0) indicated that adsorption of phenol onto seashells was feasible, spontaneous and endothermic under the examined conditions. The study shows that seashells can be used as an economic adsorbent for removal of phenol from aqueous solution.


2021 ◽  
Author(s):  
C Donga ◽  
S Mishra ◽  
A Aziz ◽  
L Ndlovu ◽  
A Kuvarega ◽  
...  

Abstract (3-aminopropyl) triethoxysilane (APTES) modified magnetic graphene oxide was synthesized and applied in the adsorption of three heavy metals, Pb(II), Cd(II) and Ni(II) from aqueous solution. An approach to prepare magnetic GO was adopted by using (3-aminopropyl) triethoxysilane (APTES) as a functionalizing agent on magnetic nanosilica coupled with GO to form the Fe3O4@SiO2-NH2/GO nanocomposite. FT-IR, XRD, BET, UV, VSM, SAXS, SEM and TEM were used to characterize the synthesized nanoadsorbents. Batch adsorption studies were conducted to investigate the effect of solution pH, initial metal ion concentration, adsorbent dosage and contact time. The maximum equilibrium time was found to be 30 min for Pb(II), Cd(II) and 60 min for Ni(II). The kinetics studies showed that the adsorption of Pb(II), Cd(II) and Ni(II) onto Fe3O4@SiO2-NH2/GO followed the pseudo-second-order kinetics. All the adsorption equilibrium data were well fitted to Langmuir isotherm model and maximum monolayer adsorption capacity for Pb(II), Cd(II) and Ni(II) were 13.46, 18.58 and 13.52 mgg-1, respectively. The Fe3O4@SiO2-NH2/GO adsorbents were reused for at least 7 cycles without the leaching of mineral core, showing the enhanced stability and potential application of Fe3O4@SiO2-NH2/GO adsorbents in water/wastewater treatment.


2018 ◽  
Vol 56 (2) ◽  
pp. 158
Author(s):  
Truong Dang Le ◽  
Hoang Vinh Tran ◽  
Le Dieu Thu ◽  
Tran Ngoc Quang ◽  
Nguyen Thi Minh Hang ◽  
...  

In this research, the potential of chitosan/Fe3O4/graphene oxide (CS/Fe3O4/GO) nanocomposite for efficient removal of Fe(III) a cationic metal ion from aqueous solutions was investigated. The synthesized CS/Fe3O4/GO was characterized by XRD, VSM and SEM techniques. Also, the various parameters affecting Fe3+ removal were investigated. Fe(III) adsorption equilibrium data were fitted well to the Langmuir isotherm and the maximum monolayer capacity (qmax), was calculated from the Langmuir as 6.5 mg.g-1. The results show that, CS/Fe3O4/GO nanocomposite, can be used as a cheap and efficient adsorbent for removal of heavy metal ions from aqueous solutions.


2018 ◽  
Vol 54 (1) ◽  
pp. 57-69 ◽  
Author(s):  
Shaheriar Haque ◽  
Sekhar Gain ◽  
Kaushik Gupta ◽  
Uday Chand Ghosh

Abstract Graphene oxide (GO) fabricated iron-aluminium oxide (GO@IAO) nanocomposite was synthesized with one-spot chemical reaction from emulsification of GO (1.0 g) in 0.2 L of 1.0 M mixed metal solution, which was characterized with some of the latest analytical tools aiming to assess methylene blue (MB) adsorption performance from aqueous solutions. Adsorption of MB on GO@IAO surfaces shows a steep increase from pH 3.0 to 5.0, but steepness declines at pH >5.0. The closeness of fitted kinetic data with the pseudo-second order (PSO) equation (R2 = 0.9845) compared to the pseudo-first order equation (R2 = 0.9527) confirms the adsorption process is of the PSO type. The MB adsorption equilibrium data can be described better by the Langmuir isotherm (R2 = 0.99) than the Freundlich isotherm (R2 = 0.96–0.97), inclining to the monolayer adsorption process. The Langmuir adsorption capacity of GO@IAO has been estimated to be 330.35 mg/g at 303 K. The MB adsorption is established to be spontaneous (–ΔG0 = 26.31–26.61 kJ/mol) owing to favourable enthalpy and entropy changes (ΔH0 = –23.38 kJ/mol; ΔS0= 0.01 kJ/mol/K). Both absolute and aqueous (1/1, v/v) alcohols regenerate the MB adsorbed GO@IAO up to 80–85%, indicating recyclability of composite.


2021 ◽  
Vol 55 (9-10) ◽  
pp. 1131-1142
Author(s):  
BENGÜ ERTAN ◽  

Stinging nettle was used as lignocellulosic adsorbent for the removal of cationic dye – malachite green (MG), and anionic dye – Congo red (CR), from aqueous solution, without any chemical pretreatment. The adsorption equilibrium data fitted well with the Langmuir model for the adsorption of both dyes, with the calculated maximum adsorption capacity of 270.27 mgg-1 and 172.14 mgg-1 for MG and CR, respectively. The adsorption process was controlled by the pseudo-second-order model in the adsorption of MG and by the pseudo-first-order model in the adsorption of CR. The thermodynamics modelling displayed that the process was spontaneous and endothermic. The π–π electron–donor interaction, hydrogen bonds and pore diffusion may also be effective, besides electrostatic interaction between the adsorbate and the adsorbent in the mechanism of MG and CR uptake.


Author(s):  
Olaniyi K Yusuff ◽  
Adenike M. O Abdulraheem ◽  
Omowumi D. Agboola

Introduction: The conversion and utilization of agricultural wastes in environmentally friendly processes have transformed these materials into useful rather than waste materials. Aim: This study investigates the adsorption of indigo blue dye from aqueous solution onto coconut shell, a low cost agricultural waste material in a batch process. Materials and Methods: Pulverized coconut shell was chemically modified and characterized using the Fourier Transform Infra Red spectroscopy and Scanning Electron Microscopy. Adsorption process using the chemically modified coconut shell was studied as a function of pH, initial dye concentration, adsorbent dose, and contact time. The adsorption equilibrium data were analyzed with Langmuir, Freundlich and Temkin isotherm models. Results: The results revealed that percentage of the indigo dye adsorbed from aqueous solution varied linearly with the adsorbent dose, concentration and time with maximum percentage dye adsorption of 88.4% at 70 mg dosage, 95.8% at 0.05 mg/L concentration and 90% at 1 hr contact time but varies non-linearly with pH with maximum percentage dye adsorption of 92.9% attained at pH of 5. The adsorption equilibrium data were analyzed with Langmuir, Freundlich and Temkin isotherm models with the Langmuir isotherm having the best fit to the adsorption process with R2 value of 0.998. The experimental data were best described by the pseudo-second order kinetics model. FTIR analyses reveal that the adsorption process was through a chemical interaction of the dye with some functional groups at the surface of the adsorbent Conclusion: The chemically modified coconut shell is an effective adsorbent for the removal of indigo dye from aqueous solution is by chemisorption process with the adsorbent surface energetically homogeneous (n < 1). Keywords: Adsorption, Indigo blue dye, Coconut Shell, Kinetics, Aqueous solution.


2021 ◽  
Vol 21 (7) ◽  
pp. 4104-4109
Author(s):  
Jong Jib Lee ◽  
Jong Ki Jeon

This study was conducted with a batch reaction to equilibrium isotherm, kinetic and thermodynamic parameters on adsorption of bromocresol purple (BCP), acid red 66 (AR 66) and acid blue 40 (AB 40) from aqueous solution by using activated carbon with nanopores. Freundlich and Temkin isotherm models were used to evaluate the suitability of isotherm for adsorption equilibrium data. The adsorption equilibrium was best fitted by Temkin model. The Freundlich separation factor values indicated that adsorption on the nanoporous activated carbon could effectively treat three dyes. The kinetic analysis of the adsorption process confirmed that it was more consistent with the pseudo second order model. The intraparticle diffusion was rate limiting step. The adsorption process of three dyes were endothermic because they were positive enthalpy values. The free energy values of three dyes decreased with increasing temperature, so that the spontaneity becomes higher with temperature increase. The activation energy value of three dyes were confirmed the physical adsorption.


2020 ◽  
Vol 15 (1) ◽  
pp. 170-181 ◽  
Author(s):  
Bei Chu ◽  
Kento Terao ◽  
Yoshimasa Amano ◽  
Motoi Machida

Abstract In this study, N-doped biochar BZ-9.5AG-30 min was prepared from bamboo by using ZnCl2 as activator and heat treated at 950 °C under NH3 gas flow for the removal of Cr(VI). The adsorbent was characterized by BET, and the amount of introduced nitrogen content and nitrogen species on BZ-9.5AG-30 min was examined by CHN elemental analyzer and X-ray photoelectron spectroscopy, respectively. Herein, the obtained BZ-9.5AG-30 min had a high specific surface area (1,610 m2/g) and high N content (4.52%). The pH of the solution had a great influence on the adsorption process, indicating that the acid condition is conducive to the adsorption process of Cr(VI). Adsorption equilibrium data of Cr(VI) were analyzed by the Langmuir and the Freundlich models. The adsorption equilibrium data were well described by the Langmuir model, and BZ-9.5AG-30 min has excellent adsorption capacity for Cr(VI) (4.31 mmol/g). BZ-9.5AG-30 min showed superior recyclability, and after five times regenerations, the adsorption capacity of BZ-9.5AG-30 min still had 63% of the initial adsorption capacity.


2019 ◽  
Vol 54 (2) ◽  
Author(s):  
Gerardo Domínguez ◽  
Rosario Hernández-Huesca ◽  
Gelacio Aguilar-Armenta

We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass high-vacuum volumetric system that permitted characterization of the energetics of the adsorption process. Adsorption equilibrium data were analyzed using the classical Freundlich equation and the Dual–Langmuir model. We employed the Clausius–Clapeyron relationship to calculate the isosteric heats of adsorption using the equilibrium data of the isotherms measured at 273.15 K and 293.15 K. The isosteric heats of reversible adsorption of both gases were smaller than the heats of total adsorption. The interaction energy of N2O with mordenite was larger than the interaction energies of N2O with either erionite or clinoptilolite. The interaction energy of NO was found to be largest with erionite.  


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