Alkaline deoxygenated graphene oxide as adsorbent for cadmium ions removal from aqueous solutions

2015 ◽  
Vol 71 (11) ◽  
pp. 1611-1619 ◽  
Author(s):  
Jun Liu ◽  
Hongyan Du ◽  
Shaowei Yuan ◽  
Wanxia He ◽  
Pengju Yan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Transmission Electron ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.

scholarly journals Synthesis and Characterisation of Graphene Oxide-Silica-Chitosan for Eliminating the Pb(II) from Aqueous Solution

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1922
Author(s):  
Sepehr Azizkhani ◽  
Ebrahim Mahmoudi ◽  
Norhafizah Abdullah ◽  
Mohd Halim Shah Ismail ◽  
Abdul Wahab Mohammad ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Removal Capacity ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their π-π interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/− 4%) mg/g based on Langmuir isotherms.

Adsorption of Zn(II) from Aqueous Solutions by Thiol-Functionalized MCM-48

2011 ◽  
Vol 413 ◽  
pp. 148-153 ◽  
Author(s):  
Xue Na Hu ◽  
Ya Han ◽  
Jia Yan Li ◽  
Jun Yan Wu ◽  
Jian Rong Chen ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Pluronic P123 ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Poly Ethylene Oxide ◽  
Ft Ir ◽  
Poly Ethylene ◽  
Poly Propylene

Thiol-functionalized MCM-48 (SH-MCM-48) was synthesized by co-condensation method, with co-templates of cetyltrimethylammonium bromide (CTAB) and nonionic poly (ethylene oxide)–poly (propylene oxide)–poly (ethylene oxide) triblock copolymer (Pluronic P123). The resulting material was characterized by XRD and FT-IR spectrum. The potential of SH-MCM-48 for adsorption Zn (II) from aqueous solution was examined. Batch adsorption studies were carried out to investigate the effect of experimental parameters including pH, metal ions concentration and adsorption time. The maximum adsorption capacities of Zn (II) onto SH-MCM-48 were 30.12, 34.01 and 38.02 mg g-1 at the temperature of 303, 313 and 323K, respectively. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model, and adsorption isotherms were fitted well with Langmuir and Freundlich models. Moreover, the adsorption thermodynamic parameters (△G0, △H0 and △S0) were measured, and indicated that the adsorption was an exothermic and spontaneous process.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

Preparation of Graphene Oxide Modified Rice Husk for Cr(VI) Removal

2019 ◽  
Vol 19 (11) ◽  
pp. 7035-7043 ◽  
Author(s):  
Tong Ouyang ◽  
Jidan Tang ◽  
Fang Liu ◽  
Chang-Tang Chang
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Alkaline Conditions ◽  
Rice Husk Biochar

The objective of this paper is to study the removal of Cr(VI) in aqueous solution by using a new graphene oxide-coated rice husk biochar composite (GO-RHB). GO-RHB is a synthetic material having a porous structure with lots of oxygen-containing functional groups and a large surface area that provide effective adsorption sites. Experiments showed that GO-RHB had higher adsorption capacity under acidic than under alkaline conditions. At pH of 2, GO-RHB has the maximum adsorption capacity(48.8 mg g−1). Equilibrium data obtained by fitting with the Langmuir and Freundlich models indicate that the reaction process was monolayer adsorption. The adsorption of Cr(VI) followed the pseudo-second-order kinetic model that illustrates chemical adsorption. Intraparticlediffusion studies further revealed that film diffusion was taking place. Moreover, the results of thermodynamics showed that the adsorption process was endothermic and spontaneous in nature. The removal mechanism of Cr(VI) was also explained in detail. The prepared adsorbent is highly efficient and might be useful than many other conventional adsorbent used for the removal of Cr(VI) from wastewater.

Equilibrium and Kinetic Studies of Benzene and Toluene Adsorption onto Microwave Irradiated-Coconut Shell Activated Carbon

2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Kinetic Studies ◽  
Coconut Shell ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Volatile Organic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Coconut Shell Activated Carbon

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.

Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 31-44 ◽  
Author(s):  
G. A. Ikhtiyarova ◽  
A. S. Özcan ◽  
Ö. Gök ◽  
A. Özcan
Keyword(s):  
Surface Area ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Thermal Analysis Techniques

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.

scholarly journals Enhanced cadmium removal from water by hydroxyapatite subjected to different thermal treatments

2020 ◽  
Vol 69 (7) ◽  
pp. 678-693
Author(s):  
R. Aouay ◽  
S. Jebri ◽  
A. Rebelo ◽  
J. M. F. Ferreira ◽  
I. Khattech
Keyword(s):  
Electron Microscopy ◽  
Sorption Process ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Cadmium Removal ◽  
Sorption Behaviour ◽  
Adsorption Mechanisms ◽  
Transmission Electron ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Hydroxyapatite powders were synthesized according to a wet precipitation route and then subjected to heat treatments within the temperature range of 200–800 °C. The prepared samples were tested as sorbents for cadmium in an aqueous medium. The best performances were obtained with the material treated at 200 °C (HAp200), as the relevant sorbent textural features (SBET – specific surface area and Vp – total volume of pores) were least affected at this low calcination temperature. The maximum adsorption capacity at standard ambient temperature and pressure was 216.6 mg g−1, which increased to 240.7 mg g−1 by increasing the temperature from 25 to 40 °C, suggesting an endothermic nature of the adsorption process. Moreover, these data indicated that a thermal treatment at 200 °C enhanced the ability of the material in Cd2+ uptake by more than 100% compared to other similar studies. The adsorption kinetic process was better described by the pseudo-second-order kinetic model. Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich isotherms were applied to describe the sorption behaviour of Cd2+ ions onto the best adsorbent. Furthermore, a thermodynamic study was also performed to determine ΔH°, ΔS°, and ΔG° of the sorption process of this adsorbent. The adsorption mechanisms were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-transmission electron microscopy (SEM-TEM) observations.

scholarly journals Adsorption Behaviour of Chromium(VI) onto Surface Modified Sugarcane Waste

2013 ◽  
Vol 28 (1-2) ◽  
pp. 113-122
Author(s):  
Kedar Nath Ghimire ◽  
Deepak Wagle ◽  
Suman Lal Shrestha
Keyword(s):  
Volume Ratio ◽  
Freundlich Isotherm ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Method ◽  
Chromium Vi ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Modified

An effective chemically modified adsorbent based on sugarcane waste has been prepared by treating with concentrated sulphuric acid in 2:1weight/volume ratio. Thus prepared adsorbent has been found to be effective in the adsorption of chromium from aqueous medium. The efficacy of the adsorbent in the removal of chromium was evaluated by batch adsorption method. The effect of initial concentration, contact time and pH of the solution was investigated. The maximum adsorption capacity onto this adsorbent was found to be 195 mg/g at their optimal pH 1 at which unmodified bagasse has only 58 mg/g. The characterization of adsorbent was done by determining surface area and Boehm’s titration method. Freundlich isotherm and pseudo-second order kinetic model gave better explanation of the adsorption process.

Kinetic Study and Equilibrium Isotherm Analysis of Cationic Dye Adsorption onto Attapulgite and Rectorite

2012 ◽  
Vol 446-449 ◽  
pp. 2960-2963
Author(s):  
Jing Yan Song ◽  
Jing Yang
Keyword(s):  
Low Cost ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Kinetic ◽  
Cationic Dye ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The adsorption properties of the attapulgite and the rectorite were investigated by removal of a cationic dye, methylene blue (MB) from aqueous solution. The attapulgite and the rectorite were characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations showed that the data fitted better with Langmuir model. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the attapulgite exhibited higher adsorption capacity for MB than rectorite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.

scholarly journals Gum Arabic-Magnetite Nanocomposite as an Eco-Friendly Adsorbent for Removal of Lead(II) Ions from Aqueous Solutions: Equilibrium, Kinetic and Thermodynamic Studies

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 224
Author(s):  
Ismat H. Ali ◽  
Mutasem Z. Bani-Fwaz ◽  
Adel A. El-Zahhar ◽  
Riadh Marzouki ◽  
Mosbah Jemmali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Gum Arabic ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Transmission Electron ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model

In this study, a gum Arabic-magnetite nanocomposite (GA/MNPs) was synthesized using the solution method. The prepared nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). The prepared composite was evaluated for the adsorption of lead(II) ions from aqueous solutions. The controlling factors such as pH, contact time, adsorbent dose, initial ion concentration, and temperature were investigated. The optimum adsorption conditions were found to be 0.3 g/50 mL, pH = 6.00, and contact time of 30 min. The experimental data well fitted the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity was determined as 50.5 mg/g. Thermodynamic parameters were calculated postulating an endothermic and spontaneous process and a physio-sorption pathway.

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