scholarly journals Preparation of Graphene Oxide Composites and Assessment of Their Adsorption Properties for Lanthanum (III)

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1040
Author(s):  
Jie Zhou ◽  
Xiaosan Song ◽  
Boyang Shui ◽  
Sanfan Wang
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Reaction Temperature ◽  
Adsorption Process ◽  
Solution Concentration ◽  
Initial Solution ◽  
Magnetic Chitosan ◽  
Adsorbent Dosage ◽  
Initial Solution Concentration ◽  
Adsorption Desorption

In this study, graphene oxide (GO) was prepared using the improved Hummers’ method, and GO was carboxylated and modified into hydroxylated graphene oxide (GOH). Diatomaceous earth (DE), which exhibits stable chemical properties, a large specific surface area, and high porosity, as well as chitosan/magnetic chitosan, was loaded by solution blending. Subsequently, carboxylated graphene oxide/diatomite/chitosan (GOH/DCS) and carboxylated graphene oxide/diatomite/magnetic chitosan (GOH/DMCS) composites were prepared through simple solid–liquid separation. The results showed that the modified GOH/DCS and GOH/DMCS composites could be used to remove lanthanum La(III)), which is a rare earth element. Different factors, such as initial solution concentration, pH of the solution, adsorbent dosage, adsorption contact time, and adsorption reaction temperature, on adsorption, were studied, and the adsorption mechanism was explored. An adsorption–desorption recycling experiment was also used to evaluate the recycling performance of the composite material. The results show that at the initial solution concentration of 50 mg·g−1, pH = 8.0, 3 g·L−1 adsorbent dosage, reaction temperature of 45 °C, and adsorption time of 50 min, the adsorption effect is the best. The adsorption process is more in line with the pseudo-second-order kinetic model and Langmuir model, and the internal diffusion is not the only controlling effect. The adsorption process is an endothermic and spontaneous chemical adsorption process. The maximum adsorption capacity of GOH/DMCS for La(III) at 308K is 302.51 mg/g through model simulation. After four adsorption–desorption cycles, the adsorption capacity of the GOH/DMCS composite for La(III) initially exceeded 74%. So, GOH/DMCS can be used as a reusable and efficient adsorbent.

scholarly journals Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

2019 ◽  
Vol 80 (7) ◽  
pp. 1357-1366
Author(s):  
Jianming Liu ◽  
Runying Bai ◽  
Junfeng Hao ◽  
Bowen Song ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Ligand Exchange ◽  
Adsorption Process ◽  
High Adsorption ◽  
Order Model ◽  
Powder Composites ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Level ◽  
Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

scholarly journals Modeling and Optimization for Production of Rice Husk Activated Carbon and Adsorption of Phenol

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Y. S. Mohammad ◽  
E. M. Shaibu-Imodagbe ◽  
S. B. Igboro ◽  
A. Giwa ◽  
C. A. Okuofu
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Rice Husk ◽  
Adsorption Process ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Variables ◽  
Adsorbent Dosage ◽  
Pretreatment Temperature

Modeling of adsorption process establishes mathematical relationship between the interacting process variables and process optimization is important in determining the values of factors for which the response is at maximum. In this paper, response surface methodology was employed for the modeling and optimization of adsorption of phenol onto rice husk activated carbon. Among the action variables considered are activated carbon pretreatment temperature, adsorbent dosage, and initial concentration of phenol, while the response variables are removal efficiency and adsorption capacity. Regression analysis was used to analyze the models developed. The outcome of this research showed that 99.79% and 99.81% of the variations in removal efficiency and adsorption capacity, respectively, are attributed to the three process variables considered, that is, pretreatment temperature, adsorbent dosage, and initial phenol concentration. Therefore, the models can be used to predict the interaction of the process variables. Optimization tests showed that the optimum operating conditions for the adsorption process occurred at initial solute concentration of 40.61 mg/L, pretreatment temperature of 441.46°C, adsorbent dosage 4 g, adsorption capacity of 0.9595 mg/g, and removal efficiency of 97.16%. These optimum operating conditions were experimentally validated.

Ammonium Removal from Aqueous Solutions Using an Ammonium Ion-Exchange Material, the Equilibrium Study

2011 ◽  
Vol 322 ◽  
pp. 102-107
Author(s):  
Lu Hua You ◽  
Xin Tan ◽  
Qiong Qiong Liu ◽  
Lin Zhao
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Solution Concentration ◽  
Initial Solution ◽  
Ammonium Ion ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Initial Solution Concentration ◽  
Exchange Material

This article investigates the removal of ammonium from aqueous solutions using the ammonium ion-exchange material prepared by the modified kaolin. Batch tests were performed under a range of conditions to assess the effect of initial solution concentration, contact time and solution PH on the performance and capacity of the media for this application. The findings show that increasing initial solution concentration and contact time provide the best performance at an optimum PH of between 6 and 7 and the maximum ammonium adsorption capacity reaches at 79mgNH4+g-1 under the experimental conditions studied. Five isotherm models were used to describe the isotherm data. Three-parameter isotherm models (Redlich–Peterson and Langmuir–Freundlich) prove a better fit than two-parameter isotherm models (Langmuir, Freundlich and Temkin). These results indicate that the ammonium ion-exchange material is a promising material for cost-effective removal of ammonium from wastewater.

scholarly journals Methylene Blue Adsorption from aqueous solution by low cost vine-wood biomass

2021 ◽  
Author(s):  
Rachida Souidi ◽  
yasmina khane ◽  
Lahcen Belarbi ◽  
Smain Bousalem
Keyword(s):  
Methylene Blue ◽  
Sulfuric Acid ◽  
Contact Time ◽  
Adsorption Process ◽  
Low Cost ◽  
Sulfuric Acid Concentration ◽  
Analytical Techniques ◽  
Batch Adsorption ◽  
Adsorbent Dosage ◽  
Adsorption Desorption

Abstract In this work, the sawdust of vine wood (VW) was treated with sulfuric acid and used to adsorb methylene blue (MB) from aqueous solutions via a batch adsorption process. The characteristics of the adsorbent were determined by various analytical techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) and Brunauer−Emmett−Teller (BET) N2 adsorption−desorption isotherms. The effects of various experimental parameters including sulfuric acid concentration, particle size of the adsorbent, pH of the solution, contact time, initial concentration, adsorbent dosage and temperature on adsorption of MB by activating sawdust were systematically investigated. The experimental results showed that the adsorption efficiency was increased with contact time and adsorbent dosage. The maximum removal efficiency was found after 180 min of solid/liquid contact with adsorbent doses of 1 g/l for sawdust. The isotherm and kinetic experimental data for MB adsorption on VW sawdust were best-fitted by Langmuir models and Pseudo-second-order, respectively. The calculated values of the entropy (ΔS°), enthalpy (ΔH°) and Gibbs energy (ΔG°) indicated that the adsorption process was exothermic in nature. These results suggest that the activated sawdust can be employed as a low-cost and environmentally friendly adsorbent for the treatment of wastewaters containing dyes.

Carboxylated carbon nanotubes-graphene oxide aerogels as ultralight and renewable high performance adsorbents for efficient adsorption of glyphosate

2020 ◽  
Vol 17 (1) ◽  
pp. 6 ◽  
Author(s):  
Hao Liu ◽  
Xueying Wang ◽  
Chaofan Ding ◽  
Yuxue Dai ◽  
Yuanling Sun ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Langmuir Isotherm ◽  
Adsorption Process ◽  
Organophosphorus Pesticide ◽  
Isotherm Model ◽  
Langmuir Isotherm Model ◽  
Graphene Oxide Aerogel ◽  
Carboxylated Carbon Nanotubes

Environmental contextGlyphosate is a highly effective and widely used organophosphorus pesticide, but its residues can harm the environment and human health. We report a carboxylated carbon nanotubes-graphene oxide aerogel that can efficiently remove glyphosate from water. This technology has great application prospects in dealing with water contaminated with glyphosate. AbstractGlyphosate, an organophosphorus pesticide, has received considerable attention in recent years owing to its carcinogenic potency. The technologies that remove glyphosate in the environment, especially in water, are important. In this work, we prepare a carboxylated carbon nanotubes-graphene oxide aerogel (cCNTs-GA) by the freeze-drying method for the adsorption of glyphosate. The prepared aerogel exhibits an ultra-low density (7.30mgcm−3), good morphology and strong mechanical strength. Meanwhile, a NaOH solution (0.5molL−1) is selected as an eluent and the adsorption parameters for the adsorption of glyphosate are optimised. The properties of the adsorbents after multiple repetitions and the adsorption mechanism of the cCNTs-GA are also studied. The results show that the adsorbent can be recycled more than 20 times and maintains a good adsorption performance. The maximum adsorption capacity of glyphosate at pH 3 is calculated from the Langmuir isotherm model (546mgg−1 at the temperature of 298K), and the cCNTs-GA exhibits a high adsorption affinity and adsorption capacity for glyphosate, as determined by the partition coefficient (PC). The pseudo-second-order kinetic model fits well to the dynamic behaviour. The equilibrium adsorption process follows the Langmuir isotherm model and the adsorption process is mainly controlled by the intraparticle diffusion model. Furthermore, thermodynamic analysis indicates that the adsorption of glyphosate on the cCNTs-GA is exothermic and spontaneous. The adsorbent is used to remove glyphosate from waste water and the adsorption capacity of the cCNTs-GA for glyphosate is higher than other adsorbents, which indicates that the developed adsorbent has a great potential application in environmental pollution treatment.

scholarly journals Optimization and Adsorption-Based Recovery of Cobalt Using Activated Disordered Mesoporous Carbons

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
I. Bernabé ◽  
J.M. Gómez ◽  
E. Díez ◽  
P. Sáez ◽  
A. Rodríguez
Keyword(s):  
Adsorption Capacity ◽  
Electrostatic Interactions ◽  
Adsorption Process ◽  
Agitation Speed ◽  
Metallic State ◽  
Mesoporous Carbons ◽  
Batch Mode ◽  
Adsorbent Dosage ◽  
High Particle ◽  
Cobalt Recovery

Kinetic and operating condition studies were studied in the batch mode. MCSG60A has a large and fast adsorption capacity, retaining 90% of the Co2+ in the solution and reaching equilibria in only 15 minutes. Among all the variables studied, the adsorbent dosage and the agitation speed favor the Co2+ adsorption until an agitation speed of 1100 rpm and 15.0 mg/L of adsorbent dosage; higher values do not increase the adsorption capacity. On the other hand, the presence of Na+ ions in the solution and high particle size hinder the adsorption process. The thermodynamic study indicated that this process is exothermic and spontaneous, mainly caused by electrostatic interactions between adsorbent and adsorbate. The adsorption is highly pH dependent: while it is optimum at basic pH, it decreases by a 70% at pH 2. The adsorption process is favored in controlled pH, in spite of the ionic strength that involves the buffer presence in the solution. As to the cobalt recovery, to preconcentrate this metal, it is tested with different acid solutions, proving that lower pH promotes this phenomena, even reaching a recovery around 98%, with HNO3 solution with 0.5 pH. Moreover, if the volume of regenerative solution is decreased to the eight part, the cobalt concentration increases five times, reaching enough concentration to facilitate its recovery in metallic state by other techniques.

Fabrication of a novel graphene oxide/β-FeOOH composite and its adsorption behavior for copper ions from aqueous solution

2015 ◽  
Vol 44 (22) ◽  
pp. 10448-10456 ◽  
Author(s):  
Tingshun Jiang ◽  
Lu Yan ◽  
Lei Zhang ◽  
Yingying Li ◽  
Qian Zhao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Copper Ions ◽  
Removal Rate ◽  
Second Order ◽  
Adsorption Behavior ◽  
Kinetics Model ◽  
Pseudo Second Order

A graphene oxide/β-FeOOH composite was prepared and its adsorption capacity was evaluated by Cu2+removal. The adsorption process was well fitted with the pseudo-second-order kinetics model. The removal rate of Cu2+reached 93.8%.

The Degradation of Organophosphorous Pesticide Wastewater by Sonophotocatalytic Oxidation Technology

2013 ◽  
Vol 781-784 ◽  
pp. 2184-2188
Author(s):  
Zhao Yan Li ◽  
Wei Song ◽  
Li Zhang
Keyword(s):  
Oxidation Reaction ◽  
Degradation Rate ◽  
Solution Concentration ◽  
Initial Solution ◽  
Optimal Time ◽  
Factors Affecting ◽  
Initial Solution Concentration ◽  
Organophosphorous Pesticide ◽  
Initial Ph ◽  
Oxidation Technology

Organophosphosphous pesticides wastewater was degradated by sonophotocatalytic oxidation technology,and some factors affecting sonophotocatalytic oxidation reaction were studied in details such as different degradation modes,the time of degradationinitial solution concentration initial pH valuethe amount of catalyst and the effect of Fenton,etc.In the end the optimal conditons were determined.The conclusion we drawed was that the optimal time of degradation was 100min initial solution concentration was 100mg/Lthe amount of catalyst AgBr/TiO2 was 0.6g,moreover the adding of Fenton could greatly enhance the degradation rate.

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
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Nickel Ion ◽  
Adsorbent Dosage ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data

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.

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