Adsorption Characteristics of Four Acid Dyes on Reaming Functionalized Mesoporous Material

2012 ◽  
Vol 550-553 ◽  
pp. 2301-2307
Author(s):  
Ping Ge ◽  
Feng Ting Li ◽  
Hong Yang
Keyword(s):  
Mesoporous Material ◽  
Adsorption Process ◽  
Activation Parameters ◽  
Sorption Kinetics ◽  
Acid Dyes ◽  
Solution Interface ◽  
Thermodynamic Activation Parameters ◽  
Pseudo Second Order ◽  
Enthalpy Of Sorption ◽  
Short Time

The present paper is aimed to investigate and develop renewable adsorption methods for four dyes removal from wastewater using pore-expanding mesoporous material. The sorption kinetics, sorption thermodynamic and the renewable adsorption test were evaluated. The adsorption process attained equilibrium within 60min, which show that the adsorbent can remove of the dye in a short time. It was shown that the process best described by the pseudo-second-order equation. Various thermodynamic activation parameters such as enthalpy of sorption △H, Gibbs energy change △G and entropy △S were estimated. The negative values of △G indicate that adsorption of dye with the adsorbent was spontaneous, while positive △H values indicative of endothermic nature of the adsorption. The negative △S values for the adsorbents show decreased randomness at the solid solution interface during the adsorption of dye. The adsorbent, washed by NaOH, can be reused by regeneration decolorizing process.

Biosorption of Acid Dyes Using Modified Chitosan: Effect of Dye Structure, Hydrogen Bonding and PH

2011 ◽  
Vol 236-238 ◽  
pp. 464-469 ◽  
Author(s):  
Zuo Hua Wang ◽  
Bo Xiang ◽  
Zheng Zhai ◽  
Yi Jiu Li
Keyword(s):  
Hydrogen Bonding ◽  
Aqueous Solutions ◽  
Sorption Kinetics ◽  
Acid Dyes ◽  
Order Model ◽  
Modified Chitosan ◽  
Ph Influence ◽  
Pseudo Second Order ◽  
Acid Orange 10 ◽  
Acid Green 25

This work investigated sorption properties of diethylenetriamine derivative of chitosan (CTSN) for removal of acid dyes (Acid Green 25 (AG25), Acid Red 18 (AR18) and Acid Orange 10 (AO10)) from aqueous solutions. Sorption kinetics was firstly evaluated. It was found that pseudo-second-order model fits well with these dyes adsorbed on CTSN. Compared with normal chitosan, CTSN has higher capacity for AR18 and AO10, but a lower value for AG25. Mechanisms and interactions of dyes with CTSN were also discussed by study the effect of pH, influence of hydrogen-bonding and comparing the sorption capacities.

Sorption of Th(IV) onto ZnO nanoparticles and diatomite-supported ZnO nanocomposite: kinetics, mechanism and activation parameters

2016 ◽  
Vol 104 (9) ◽  
pp. 635-647 ◽  
Author(s):  
Sabriye Yusan ◽  
Anastasia Bampaiti ◽  
Sema Erenturk ◽  
Fotini Noli ◽  
Mahmut A. A. Aslani ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Zno Nanoparticles ◽  
Activation Parameters ◽  
Sorption Kinetics ◽  
Second Order ◽  
Experimental Conditions ◽  
Maximum Sorption ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
First Time

Abstract In this study, for the first time ZnO nanoparticles and diatomite-supported ZnO nanocomposite have been utilized as adsorbent for the removal of Th(IV) ions from aqueous solutions under different experimental conditions. The Langmuir, Freundlich, Temkin and Dubinin– Radushkevich (D–R) isotherms were used to analyze the equilibrium data. The sorption equilibrium data were fitted well to the Langmuir isotherm with maximum sorption capacities values was found to be 1.105 mmol/g and 0.320 mmol/g for ZnO nanoparticles and diatomite supported ZnO nanocomposite, respectively. Pseudo-first and pseudo-second order equations, Intraparticle diffusion and Bangham’s models were considered to evaluate the rate parameters and sorption mechanism. Sorption kinetics were better reproduced by the pseudo-second order model (R2 > 0.999), with an activation energy (Ea) of +99.74 kJ/mol and +62.95 kJ/mol for ZnO nanoparticles and diatomite-supported ZnO nanocomposite, respectively. In order to specify the type of sorption reaction, thermodynamic parameters were also determined. The evaluated ΔG* and ΔH* indicate the non-spontaneous and endothermic nature of the reactions. The results of this work suggest that both of the used materials are fast and effective adsorbents for removing Th(IV) from aqueous solutions and chemical sorption plays a role in controlling the sorption rate.

scholarly journals Characterization and utilization of Sargassum linifolium and Stypopodium schimperi polysaccharides as blue inhibitors for steel electo-polishing

2020 ◽  
Author(s):  
Abeer A. M. El-Sayed ◽  
F. M. Abouzeid ◽  
Mona M. Ismail ◽  
Gehan M. ElZokm
Keyword(s):  
Steel Surface ◽  
Inhibition Efficiency ◽  
Adsorption Process ◽  
Activation Parameters ◽  
Limiting Current ◽  
High Concentration ◽  
Surface Appearance ◽  
Solution Interface ◽  
Ft Ir ◽  
Crude Polysaccharide

Abstract Different polysaccharides extracts (crude polysaccharide, fucoidan and alginate) from Sargassum linifolium and Stypopodium schimperi were examined as inhibitors for carbon-steel anodic dissolution process in 8M phosphoric acid. Anode potential –limiting current relationship was measured and comparing of gradually increasing algae extract concentrations (from 20 to 350 ppm). The limiting current decrease while inhibition Efficiency % increases as the concentrations of all these extracts increase. Fucoidan from S. linifolium is considered as most retardation effect. The extracts retardation mechanism is depending on adsorption process at the steel metal which proved by SEM. Also, SEM shows that high concentration (350 ppm) from St. schimperi crude polysaccharide, Sargassum linifolium fucoidan and Stypopodium. schimperi alginate extracts have promising effect on the surface texture. The data of Langmuir and the kinetic-thermodynamic isotherms were determined to clarify the nature of adsorption of extract on metal –solution interface. The activation energy (Ea) and activation parameters (ΔH*, ΔS*, and ΔG*) were determined and gave indication for strong interaction between the inhibitor and the steel surface. The extract feature was investigated via FT-IR. The polysaccharides from brown algae especially fucoidan manifest preferable as natural electro-polishing blue inhibitor. Surface morphology study confirmed that addition of algae extract to steel dissolution bath enhance surface appearance and its texture quality to great extent.

Surface interaction of sweet potato peels (Ipomoea batata) with Cd(II) and Pb(II) ions in aqueous medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Aqueous Medium ◽  
Sweet Potato ◽  
Adsorption Process ◽  
Low Cost ◽  
Correlation Coefficients ◽  
Order Kinetic ◽  
Thermodynamic Evaluation ◽  
Dissociative Mechanism ◽  
Pseudo Second Order ◽  
Potato Peels

The removal of Cd(II) and Pb(II) ions from aqueous medium was studied using potato peels biomass. The adsorption process was evaluated using Atomic Absorption Spectrophotometer (AAS). The Vibrational band of the potato peels was studied using Fourier Transform Infrared Spectroscopy (FTIR). The adsorption process was carried out with respect to concentration, time, pH, particle size and the thermodynamic evaluation of the process was carried at temperatures of 30, 40, 50 and 60(0C), respectively. The FTIR studies revealed that the potato peels was composed of –OH, -NH, –C=N, –C=C and –C-O-C functional groups. The optimum removal was obtained at pH 8 and contact time of 20 min. The adsorption process followed Freundlich adsorption and pseudo second-order kinetic models with correlation coefficients (R2) greater than 0.900. The equilibrium adsorption capacity showed that Pb(II) ion was more adsorbed on the surface of the potato peels biomass versus Cd (II) ion (200.91 mg/g > 125.00 mg/g). The thermodynamic studies indicated endothermic, dissociative mechanism and spontaneous adsorption process. This study shows that sweet potato peels is useful as a low-cost adsorbent for the removal of Cd(II) and Pb(II) ions from aqueous medium.

Kinetic Studies of [4n+2]π-Thermal Cyclodimerization of 1-(3-Pyridazinyl)-3-oxidopyridinium Betaines

1992 ◽  
Vol 57 (9) ◽  
pp. 1951-1959 ◽  
Author(s):  
Madlene L. Iskander ◽  
Samia A. El-Abbady ◽  
Alyaa A. Shalaby ◽  
Ahmed H. Moustafa
Keyword(s):  
Energy Gap ◽  
Activation Parameters ◽  
Kinetic Studies ◽  
Cyclic Transition ◽  
Concerted Mechanism ◽  
First Order ◽  
Thermodynamic Activation Parameters ◽  
Cyclic Transition State ◽  
Complete Dissociation ◽  
Homo Lumo

The reactivity of the base induced cyclodimerization of 1-(6-arylpyridazin-3-yl)-3-oxidopyridinium chlorides in a pericyclic process have been investigated kinetically at λ 380 nm. The reaction was found to be second order with respect to the liberated betaine and zero order with respect to the base. On the other hand dedimerization (monomer formation) was found to be first order. It was shown that dimerization is favoured at low temperature, whereas dedimerization process is favoured at relatively high temperature (ca 70 °C). Solvent effects on the reaction rate have been found to follow the order ethanol > chloroform ≈ 1,2-dichloroethane. Complete dissociation was accomplished only in 1,2-dichloroethane at ca 70 °C. The thermodynamic activation parameters have been calculated by a standard method. Thus, ∆G# has been found to be independent on substituents and solvents. The high negative values of ∆S# supports the cyclic transition state which is in favour with the concerted mechanism. MO calculations using SCF-PPP approximation method indicated low HOMO-LUMO energy gap of the investigated betaines.

scholarly journals Eggshell Powder as an Adsorbent for Removal of Fluoride from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Fluoride Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Maximum Removal

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

Study on the Formaldehyde Adsorption Kinetics of Dry Waters

2014 ◽  
Vol 809-810 ◽  
pp. 907-911
Author(s):  
Jun Long Wang ◽  
Jie Hou ◽  
Ting Jiang ◽  
Yong Jun He ◽  
Yao Dong Liang
Keyword(s):  
Adsorption Kinetics ◽  
High Speed ◽  
Adsorption Process ◽  
Average Diameter ◽  
Adsorption Rate ◽  
Absorption Kinetics ◽  
Order Model ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Formaldehyde Adsorption

Dry waters with an average diameter of 82 μm were prepared by a high speed mixed route. The formaldehyde absorption kinetics of dry waters was investigated by simulating indoor formaldehyde pollution in glass chamber. The results showed that pseudo-second order model could be used to simulate the adsorption process; the adsorption rate was highest in the initial 60 minutes; when the adsorption lasted for 180 minutes, the adsorption reached equilibrium.

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