Adsorption of Cr(VI) onto the Cross-Linked Cationic Starch and the Establishment of the Adsorption Isotherm and Kinetic Equation

2012 ◽  
Vol 518-523 ◽  
pp. 285-288
Author(s):  
Yuan Dong Xu ◽  
Xiang Yang Yan
Keyword(s):  
Kinetic Equation ◽  
Adsorption Isotherm ◽  
Equilibrium State ◽  
Modified Starch ◽  
Trimethyl Ammonium Chloride ◽  
Cationic Starch ◽  
Adsorption Time ◽  
Adsorption Performance ◽  
The Cross ◽  
Cationic Reagent

Glycidyl trimethyl ammonium chloride (GTA) has been synthesized and used as cross-linked cationic reagent to prepare modified starch. The adsorption behavior of Cr(VI) onto the cross-linked cationic starch was studied systematically. The adsorption time and the temperature took great effects on the adsorption performance of the adsorbent. After a suitable time the adsorption could reach an equilibrium state and the adsorption capacity increased with the decrease of the temperature. The adsorption isotherm and the kinetic equation were established and they fit well with the Freundlich and Lagergren models, respectively. The used adsorbent was regenerated with acid medium and the recycling of the regenerated adsorbent has also been investigated.

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.

Preparation and Adsorption Performance of Cu (II)-Imprinted ALG-CTS Complex Microspheres

2012 ◽  
Vol 268-270 ◽  
pp. 229-232 ◽  
Author(s):  
Wei Ying Zhang ◽  
Dan Chen ◽  
Xiao Li ◽  
Xiao Guang Ying
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ionic Interaction ◽  
Experimental Conditions ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorption Performance ◽  
Series Of Experiments ◽  
Equilibrium Adsorption Isotherm

We prepared alginate-chitosan (ALG-CTS) complexes through ionic interaction, and then obtained Cu (II)-imprinted alginate-chitosan complex microspheres (Cu-ALG-CTS) by coupling with ionic imprinting technology. To investigate the effects of experimental conditions on adsorption behavior, we performed a series of experiments including changing the initial concentration of Cu (II) ions and adsorption time. We found that the adsorption capacity increases with the initial concentration of Cu (II) ions. The Cu (II) ions adsorption reaches the maximum of 70.54mg/g after adsorbing for 13h when the initial concentration of Cu (II) ions is 60μg/ml. Cu-ALG-CTS shows much higher adsorption for Cu (II) ions than Zn (II) ions. And the adsorption kinetics and equilibrium adsorption isotherm were further studied.

Adsorption Characteristics of Hg2+ Ions Using Fe3O4/Chitosan Magnetic Nanoparticles

2011 ◽  
Vol 291-294 ◽  
pp. 72-75 ◽  
Author(s):  
Bo Lin Liang
Keyword(s):  
Magnetic Nanoparticles ◽  
Adsorption Capacity ◽  
Uniform Distribution ◽  
Ph Value ◽  
Cross Linking ◽  
Mercury Ions ◽  
Dialdehyde Starch ◽  
Adsorption Time ◽  
Adsorption Performance ◽  
Chemical Cross Linking

Fe3O4/chitosan magnetic nanoparticles were prepared by chemical cross-linking technique, using dialdehyde starch as a crosslinker, and the adsorption performance of the adsorbent toward Hg2+ was investigated. The adsorption capacity of mercury ions was greatly affected by pH value, adsorption doses and adsorption time. Results indicated that optimal adsorption conditions were pH value, 6, adsorption doses, 140 mg.L-1, adsorption time, 20 min, and the adsorption capacity was 25.12 mg.g-1. The well-defined nanoparticles with a uniform distribution were observed.

The Decoloration Property of Modified Reed Absorbent for Alkaline Fuchsin Wastewater

2013 ◽  
Vol 821-822 ◽  
pp. 365-368
Author(s):  
Yu Ying
Keyword(s):  
Adsorption Isotherm ◽  
Ph Value ◽  
Adsorption Time ◽  
Adsorption Condition ◽  
Adsorption Temperature ◽  
Naoh Solution ◽  
Adsorbent Dose

The modified reed absorbent was obtained by the being treated process with NaOH solution. The decoloration property of modified reed for alkaline fuchsin was studied under different conditions. The effects of adsorbent dose, adsorption temperature, adsorption time and pH value on the decoloration property were investigated, and the optimal adsorption condition was gotten,, the discoloration rate was above 95%. The adsorption isotherm was well represented by the Langmuir.

A Statistical Derivation of Langmuir's Adsorption Isotherm

1935 ◽  
Vol 31 (2) ◽  
pp. 260-264 ◽  
Author(s):  
R. H. Fowler
Keyword(s):  
Adsorption Isotherm ◽  
Equilibrium State ◽  
Ab Initio ◽  
Statistical Methods ◽  
Adsorbed Layer ◽  
Gas Pressure ◽  
Saturation Effect ◽  
Adsorbed Molecules ◽  
Statistical Derivation ◽  
Image Position

The commonest form of Langmuir's adsorption isotherm iswhere θ is the fraction of the surface of the solid covered by adsorbed molecules, p the gas pressure in equilibrium with the adsorbed layer and A = A (T) a function of the temperature alone. This formula is usually derived by a kinetic argument which balances the rates of deposition and re-evaporation. It is perhaps not without interest to show that formula (1) and similar formulae can be obtained directly by the usual statistical methods which evaluate all the properties of the equilibrium state of any assembly. The ordinary derivation is apt to obscure the essentially thermodynamic character of (1) and to lead one to think that its form depends on the precise mechanisms of deposition and re-evaporation, whereas in fact it depends only on the whole set of states, adsorbed and free, accessible to the molecules in question. By suitable use of the usual technique for handling assemblies obeying the Fermi-Dirac statistics the saturation effect can be naturally incorporated in the theory ab initio.

The Adsorption of Zn2+ onto Chitosan-Aluminum Oxide Composite Material

2014 ◽  
Vol 1056 ◽  
pp. 58-61
Author(s):  
Xue Jun Ren ◽  
Qing Gang Gao ◽  
Ming Gao
Keyword(s):  
Composite Material ◽  
Aluminum Oxide ◽  
Raw Material ◽  
Chemical Bonds ◽  
Adsorption Time ◽  
Oxide Composite ◽  
Adsorption Performance ◽  
Adsorption Temperature ◽  
Oxide Composite Material ◽  
Temperature Time

Chitosan-aluminum oxide composite material was synthesized through chemical bonds with chitosan and isopropanol aluminum as raw material, whose structure was characterized by IR, TG. The influence of reaction conditions on adsorption performance were studied, such as temperature, time. Results show that in the composite materials, chemical bonds were existed between aluminum and chitosan, inorganic aluminum oxide evenly dispersed in the surface of chitosan molecular, the thermal stability of the composites is improved significantly. Chitosan-aluminum oxide composite material has good adsorption performance of Zn2+ in solution. The adsorption quantity of Zn2+ increases with the increasing of the adsorption temperature and the adsorption time, and the best adsorption time is 7.0h.

Study on Structure of Amphoteric Starch and Its Reinforcing Effect on Secondary Fiber

2011 ◽  
Vol 236-238 ◽  
pp. 1112-1115
Author(s):  
Hong Wei Zhang ◽  
Guo Ping Zheng
Keyword(s):  
Control Sample ◽  
Amorphous Region ◽  
Crystalline Region ◽  
Paper Strength ◽  
Cationic Starch ◽  
Reinforcing Effect ◽  
Dry Process ◽  
Amphoteric Starch ◽  
Reinforcing Effects ◽  
Cationic Reagent

In the presented work, a series of the phosphate amphoteric cassava starch were synthesized by a two-step semi-dry process with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CTA) as the cationic reagent and phosphate mixture as the anionic reagent. The structure of the amphoteric starch was characterized by FTIR and XRD. The reinforcing effects of the amphoteric starch on the secondary fiber were also studied. The results indicated that the reaction occurred not only in the amorphous region, but also in its crystalline region. When the cationic starch reacted with different amount of phosphates, the degree of cation substitution (DSc) of products was decreased with the dosage of the phosphates. When cationic starch with different DSc reacted with the same amount of phosphates, the degree of anion substitution (DSa) of products was decreased with the DSc. All the amphoteric starch showed reinforcing effect on the secondary fiber. The No. 7 sample showed better reinforcing effects on paper strength due to its higher total degree of substitution (0.095), proper DSa/DSc ratio (DSc = 0.067, DSa = 0.028) and interior modification of the starch granule. Compared with the control sample, the secondary fiber paper with 1.0 wt % (relative to dried pulp) of 7# modified starch showed 23.5%, 20.3% and 29.4% increases in tensile index, tearing index, and burst index, respectively.

scholarly journals Preparation and Characterization of Magadiite–Magnetite Nanocomposite with Its Sorption Performance Analyses on Removal of Methylene Blue from Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 607 ◽  
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Guoqing Hu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Aqueous Solutions ◽  
Langmuir Adsorption Isotherm ◽  
Order Kinetic ◽  
Langmuir Adsorption ◽  
Adsorption Performance ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The magadiite–magnetite (MAG–Fe3O4) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe3O4 and the high adsorption capacity of pure magadiite (MAG). MAG–Fe3O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe3O4 nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe3O4 was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe3O4 were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe3O4 improved remarkably compared with MA and Fe3O4. The adsorption capacity of MAG–Fe3O4 and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe3O4 was better than that of MAG and Fe3O4. Moreover, the adsorption behavior of MB on MAG–Fe3O4 was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe3O4 nanocomposite was a monolayer adsorption.

Preparation and Utilization of Lignin Ionic Adsorbent for the Removal of Cr(VI) from Aqueous Solution

2012 ◽  
Vol 588-589 ◽  
pp. 47-50
Author(s):  
Ze Sheng Cheng ◽  
Zhen Wang ◽  
Yu Liu ◽  
Na Na Bo
Keyword(s):  
Aqueous Solution ◽  
Quaternary Ammonium ◽  
Organic Medium ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Alkali Lignin ◽  
Adsorption Performance ◽  
Lignin Modification ◽  
As Adsorption ◽  
Better Than

Alkali lignin, Modification, Quaternary ammonium salt, Cr(Ⅵ), Anion adsorbent Abstract. LIA(lignin ionic adsorbent) was synthesized by modified alkali lignin after reaction with epichlorohydrin and dimethylamine or diethylamine by using the modifying agents of N-methylmorpholine (NMM) in the presence of organic medium of N,N-dimethylformamide(DMF). The LIA was characterized by FTIR spectroscopy and elements analysis， the yield of products and the adsorbent capabilities for Cr(Ⅵ) from aqueous solution were also exploited. The factors that might influent the adsorption performance were investigated, such as adsorption time, reagent dosage and the initial concentration of Cr(Ⅵ). It was found that the efficiency of Cr(Ⅵ) removal were better when the amount of the sorbent was increased. But the removal efficiency was reduced as the initial concentration of Cr(Ⅵ) increased. The contrast result of the two synthesis processes also proved the yields of sample 3 (modified alkali lignin using diethylamine) was higher than sample 2 (modified alkali lignin using dimethylamine). And the adsorption capabilities of sample 3 were also better than sample 2.

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