Adsorption of Zn(II) in Aqueous Solutions by Kaolin

2012 ◽  
Vol 554-556 ◽  
pp. 2041-2044
Author(s):  
Jun Jin Chen ◽  
Guo Xiang Pan ◽  
Yan Fei Yu
Keyword(s):  
Kinetic Equation ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Model Fitting ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Initial Ph ◽  
Higher Temperature ◽  
Better Than ◽  
Adsorption Activation Energy

In this paper, adsorption performance of Zn(II) in simulative waste water by kaolin was studied, and the influences of solution initial pH value, temperature, adsorption time, concentration of Zn(II) were tested. Moreover, the thermodynamic parameters and kinetic equation were calculated. The results show that Zn(II) adsorption capacity firstly increases and then decreases as the pH increases, and the higher temperature, the better adsorption capacity. The Zn(II) adsorption occurs mainly within 60 minutes, and then leveling off. The calculations show that linear correlation coefficient (R2) of langmuir equation is better than the freundlich model fitting results, and Zn(II) adsorption can occur spontaneously, is an endothermic and entropy increasing process. In addition, first-order kinetic equation is more suitable for the description of Zn(II) adsorption mechanism, and adsorption activation energy equals 21.51 kJ•mol-1.

Study on the Adsorption Performance of Zn(II) over Bentonite

2013 ◽  
Vol 575-576 ◽  
pp. 276-279
Author(s):  
Guo Xiang Pan ◽  
Ya Jing Zhang ◽  
Da Gan Chai ◽  
Yan Fei Yu
Keyword(s):  
Kinetic Equation ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Langmuir Equation ◽  
Adsorption Time ◽  
Adsorption Performance ◽  
Initial Ph ◽  
Increasing Process ◽  
Adsorption Activation Energy

Bentonite is applied in the simulative waste water containing Zn (II) ions in this paper, and the influences of initial pH value, temperature, adsorption time, Zn (II) concentration on the adsorption performance have been tested, and thermodynamic and kinetic equation are fitted. The results show that Zn (II) adsorption capacity increases firstly and then tends to balance as the pH increases. The higher the temperature is, the better adsorption capacity is. Zn (II) adsorption occurs within 60 minutes. Langmuir equation is used to fit adsorption thermodynamic equation, which indicates that the adsorption can occur spontaneously, and it is an endothermic and entropy increasing process. In addition, a kinetic equation is more suitable for the description of Zn (II) adsorption mechanism, and adsorption activation energy calculated is 6.90 kJ/mol.

scholarly journals Adsorption Equilibrium of a Herbicide (Pendimethalin) onto Natural Clay

2005 ◽  
Vol 23 (6) ◽  
pp. 437-453 ◽  
Author(s):  
M.S. El-Geundi ◽  
T.E. Farrag ◽  
H.M. Abd El-Ghany
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Natural Clay ◽  
Freundlich Model ◽  
Adsorption Data ◽  
Effect Of Particle Size ◽  
System Variables ◽  
Better Than

The equilibrium adsorption of a herbicide (pendimethalin) onto natural clay from aqueous solutions was studied experimentally using different system variables. The influence of such variables, such as particle size (dp), pH and temperature, on the adsorption capacity was studied. Equilibrium modelling was carried out using the Langmuir, Freundlich and Redlich—Peterson models with the corresponding constants being calculated for the different system variables. The results indicate that the maximum adsorption capacity (qmax) at an acidic pH value (3.44) was approximately double that observed at an alkaline pH value (9.62). It was also found that the effect of particle size was significant and that the temperature plays an interesting role in the adsorption process. The enthalpy change (ΔH) for adsorption was evaluated as −29.36 kJ/mol. It is clear from the results of this study that the Freundlich model fitted the experimental adsorption data significantly better than the Langmuir or the Redlich—Peterson models.

Synthesis and Characterization of Zeolite X Obtained from Coal Gangue for Adsorption of Cu2+

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Copper Ions ◽  
Removal Rate ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Zeolite X ◽  
Initial Ph

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.

Adsorption kinetics and thermodynamics of acid Bordeaux B from aqueous solution by graphene oxide/PAMAMs

2015 ◽  
Vol 72 (7) ◽  
pp. 1217-1225 ◽  
Author(s):  
Fan Zhang ◽  
Shengfu He ◽  
Chen Zhang ◽  
Zhiyuan Peng
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Freundlich Model ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Effects Of Media ◽  
Better Than

Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GO with 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMs was 2.5. The maximum adsorption capacity increased from 325.78 to 520.83 mg/g with the increase in temperature from 298 to 328 K. The equilibrium data followed the Langmuir isotherm model better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

Effect of Modification with Nitric Acid and Hydrogen Peroxide on Chromium (VI) Adsorption by Activated Carbon Fiber

2012 ◽  
Vol 518-523 ◽  
pp. 2099-2103
Author(s):  
Guang Zhou Qu ◽  
Hai Bing Ji ◽  
Ran Xiao ◽  
Dong Li Liang
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Nitric Acid ◽  
Carbon Fiber ◽  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Activated Carbon Fiber ◽  
Order Kinetic ◽  
Adsorption Amount

The activated carbon fiber (ACF) was treated by different concentration nitric acid (HNO3) and hydrogen peroxide (H2O2) oxidization to enhance its adsorption capacity to hexavalent chromium (Cr6+) ion. The adsorption amount and adsorption kinetics of Cr6+ion on ACFs, and the surface chemical groups were investigated. The results showed that the modified ACFs with 1% HNO3and 10% H2O2had a better adsorption capacity, respectively. The adsorption amount of ACFs was affected strongly solution pH value, and decreased significantly with increasing of the pH value. The adsorption kinetics indicated that the adsorption rates of Cr6+ ion on different modified ACFs were well fitted with the pseudo-second-order kinetic model. After 1% HNO3and 10% H2O2modification, respectively, the total acidic oxygen-containing groups on ACFs surface had an increase obviously, which might be enhance the adsorption amount of Cr6+ion on ACFs.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

Adsorption of cadmium by biochar produced from pyrolysis of corn stalk in aqueous solution

2016 ◽  
Vol 74 (6) ◽  
pp. 1335-1345 ◽  
Author(s):  
Fengfeng Ma ◽  
Baowei Zhao ◽  
Jingru Diao
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Ionic Strength ◽  
Ph Value ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Corn Stalk ◽  
Adsorbent Dosage ◽  
Initial Ph ◽  
Adsorbent Particle

The purpose of this work is to investigate adsorption characteristic of corn stalk (CS) biochar for removal of cadmium ions (Cd2+) from aqueous solution. Batch adsorption experiments were carried out to evaluate the effects of pH value of solution, adsorbent particle size, adsorbent dosage, and ionic strength of solution on the adsorption of Cd2+ onto biochar that was pyrolytically produced from CS at 300 °C. The results showed that the initial pH value of solution played an important role in adsorption. The adsorptive amount of Cd2+ onto the biochar decreased with increasing the adsorbent dosage, adsorbent particle size, and ionic strength, while it increased with increasing the initial pH value of solution and temperature. Cd2+ was removed efficiently and quickly from aqueous solutions by the biochar with a maximum capacity of 33.94 mg/g. The adsorption process was well described by the pseudo-second-order kinetic model with the correlation coefficients greater than 0.986. The adsorption isotherm could be well fitted by the Langmuir model. The thermodynamic studies showed that the adsorption of Cd2+ onto the biochar was a spontaneous and exothermic process. The results indicate that CS biochar can be considered as an efficient adsorbent.

Adsorption kinetics and isotherm of vanadium with melamine

2017 ◽  
Vol 75 (10) ◽  
pp. 2316-2321 ◽  
Author(s):  
Hao Peng ◽  
Zuohua Liu ◽  
Changyuan Tao
Keyword(s):  
Adsorption Kinetics ◽  
Impact Factors ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm ◽  
Langmuir And Freundlich Models

Melamine, possessing three free amino groups and three aromatic nitrogen atoms in its molecule, has great potential as an adsorbent for metal ions. We investigated three impact factors of the adsorption process: the initial pH of the vanadium solution, contact time and reaction temperature. The adsorption kinetics could be accurately described by the pseudo-second-order kinetic model. Langmuir and Freundlich models fitted well with the experimental equilibrium data, and the maximal adsorption capacity was found to be 1,428.57 mg vanadium/g melamine, and the Freundlich model showed the adsorption is privilege type.

scholarly journals Sorption Efficiency of a New Sorbent towards Cadmium(II): Methylphosphonic Acid Grafted Polystyrene Resin

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nacer Ferrah ◽  
Omar Abderrahim ◽  
Mohamed Amine Didi ◽  
Didier Villemin
Keyword(s):  
Metal Ion ◽  
Ph Value ◽  
Ion Concentration ◽  
Methylphosphonic Acid ◽  
Order Kinetic ◽  
Elementary Analysis ◽  
Optimum Ph ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Polystyrene Resin

A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization by FTIR and elementary analysis, the new resin has been investigated in liquid-solid extraction of cadmium(II). The results indicated that phosphonic resin could adsorb Cd(II) ion effectively from aqueous solution. The adsorption was strongly dependent on the pH of the medium and the optimum pH value level for better sorption was between 3.2 and 5.2. The influence of other analytical parameters including contact time, amount of resin, metal ion concentration, and the presence of some electrolytes was investigated. The maximum uptake capacity of Cd(II) ions was 37,9 mg·g−1grafted resin at ambient temperature, at an initial pH value of 5.0. The overall adsorption process was best described by pseudo second-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. Furthermore, more than 92% of Cd(II) could be eluted by using 1.0 mol·L−1HCl in one cycle.

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