scholarly journals KINETIC STUDIES OF ADSORPTION PROCESS OF CHROMIUM IONS FROM AQUEOUS SOLUTION.

2016 ◽  
Vol 4 (10) ◽  
pp. 545-550 ◽  
Author(s):  
Dimple Lakherwal ◽  
◽  
H.P. Singh ◽  
V.K. Rattan ◽  
◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Chromium Ions

scholarly journals Adsorption of Phenol from Aqueous Solution by Aminated Hypercrosslinked Polymers

2005 ◽  
Vol 23 (4) ◽  
pp. 335-346 ◽  
Author(s):  
Yue Sun ◽  
Jin-Long Chen ◽  
Ai-Min Li ◽  
Fu-Qiang Liu ◽  
Quan-Xing Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Amino Group ◽  
Commercial Resin ◽  
The Matrix ◽  
Basic Anion Exchange Resin ◽  
Tertiary Amino ◽  
Basic Anion ◽  
Hypercrosslinked Polymeric Adsorbent

The adsorption of phenol from aqueous solution onto the hypercrosslinked polymeric adsorbent NDA-100 and its dimethylamine aminated derivatives AH-1, AH-2 and AH-3, the commercial resin Amberlite XAD-4 and the weakly basic anion-exchange resin D301 was compared. Of the tested polymers, the aminated hypercrosslinked resins had the highest adsorption capacities. The empirical Freundlich equation was successfully employed to describe the adsorption process. The specific surface area and the micropore structure of the adsorbent together with the tertiary amino group on the matrix affected the adsorption performance towards phenol. Furthermore, these factors also influenced the thermodynamic properties. Kinetic studies demonstrated that the presence of the tertiary amino group on the polymer matrix decreased the adsorption rate and increased the apparent activation energy of the adsorption process.

scholarly journals Sorption of Bivalent Ions by Cymbopogon citratus: Characterisation and Investigation of Biosorptive Capacity and Mechanism

2018 ◽  
Vol 4 (3) ◽  
pp. 297-302
Author(s):  
S. Jayashree ◽  
Jeyavathana Samuel ◽  
R. Vashantha
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Adsorption Process ◽  
Low Cost ◽  
Kinetic Studies ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Physical Parameters ◽  
Cymbopogon Citratus ◽  
Equilibrium Data

The main objective of this study was to investigate the removal of cadmium(II) ions from aqueous solution using raw Cymbopogon citratus as an adsorbent. It was characterized by FT-IR, XRD, SEM-EDAX and its physical parameters were analyzed. Different factors such as pH, contact time, initial concentration and temperature were studied. Maximum adsorption was taken place at the optimum pH of 6 and the equilibrium data were analyzed by Langmuir, Freundlich and Temkin Isotherm models. Among those isotherm models Langmuir and Temkin were fitted well with good correlation coefficient (R2). The negative values of ΔG⁰ for all temperature shows the adsorption process for cadmium(II) ion was spontaneous in nature and feasible. The negative value of enthalpy change ΔH⁰ shows the adsorption process is exothermic and the positive value of ΔS⁰ indicates the disorderness or randomness process of adsorption. The positive value of Ea indicates the higher solution temperature favors the adsorption of metal ion onto RCC. The experimental data were analyzed by kinetic studies such as pseudo-first order, pseudo-second order and intra-particle diffusion models. Desorption was also studied and the recovery of the adsorbent was found to be 10%. Thus on the basis of these investigations the present study concludes that the raw Cymbopogon citratus (RCC) was found to be highly effective, nontoxic, environmental friendly and low cost adsorbent for the removal of toxic Cd(II) ions from aqueous solution.

scholarly journals Thermodynamics and Kinetic Studies for the Adsorption Process of Methyl Orange by Magnetic Activated Carbons

2021 ◽  
Vol 14 ◽  
pp. 117862212110133
Author(s):  
Ana Karen Cordova Estrada ◽  
Felipe Cordova Lozano ◽  
René Alejandro Lara Díaz
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Surface Area ◽  
Adsorption Process ◽  
Activated Carbons ◽  
Good Description ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Bet Analysis

This study investigates the adsorption behavior of methyl orange (MO) by magnetic activated carbons (MACs) with different ratios of AC: Magnetite from aqueous solution. Batch experiments for MO adsorption were carried out for evaluating the thermodynamics and kinetics parameters onto the MAC adsorbents. Variables such as pH, initial concentration of the dye, contact time, and temperature have been analyzed. The physicochemical characteristics of MACs were analyzed by scanning electron microscopy (SEM), surface area analyzer (BET), and X-ray power diffraction. The results of SEM and BET analysis showed that MAC adsorbents present a porous structure and large surface area, suitable conditions for the adsorption process. The X-ray diffraction patterns of MACs revealed that the adsorbents possess magnetite as magnetic material. Adsorption kinetic studies carried out onto MACs showed that the pseudo-second-order model provides a good description of the kinetic process. The adsorption equilibrium results were well adjusted to the Langmuir isotherm, showing that the maximum adsorption capacity was for MACs with a ratio 3:1 and 2:1 AC/magnetite. Thermodynamic analysis declares that the adsorption process was established as spontaneous, endothermic, and physical adsorption in nature. The results of the this study indicated that MAC adsorbents can be used successfully for eliminating MO from aqueous solution.

scholarly journals Adsorption Behavior of Methylene Blue Dye by Novel Crosslinked O-CM-Chitosan Hydrogel in Aqueous Solution: Kinetics, Isotherm and Thermodynamics

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3659
Author(s):  
Nouf Faisal Alharby ◽  
Ruwayda S. Almutairi ◽  
Nadia A. Mohamed
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Thermodynamic Parameters ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Kinetic Studies ◽  
Blue Dye ◽  
Chitosan Hydrogel ◽  
Adsorption Capacities ◽  
Increasing Temperature

The chemical cross-linking of carboxymethyl chitosan (O-CM-chitosan), as a method for its modification, was performed using trimellitic anhydride isothiocyanate to obtain novel cross-linked O-CM-chitosan hydrogel. Its structure was proven using FTIR, XRD and SEM. Its adsorption capacity for the removal of Methylene Blue (MB) dye from aqueous solution was studied. The effects of different factors on the adsorption process, such as the pH, temperature and concentration of the dye, in addition to applications of the kinetic studies of the adsorption process, adsorption isotherm and thermodynamic parameters, were studied. It was found that the amount of adsorbed MB dye increases with increasing temperature. A significant increase was obtained in the adsorption capacities and removal percentage of MB dye with increasing pH values. An increase in the initial dye concentration increases the adsorption capacities, and decreases the removal percentage. It was found that the pseudo-second-order mechanism is predominant, and the overall rate of the dye adsorption process appears to be controlled by more than one step. The Langmuir model showed high applicability for the adsorption of MB dye onto O-CM-chitosan hydrogel. The value of the activation energy (Ea) is 27.15 kJ mol−1 and the thermodynamic parameters were evaluated. The regeneration and reuse of the investigated adsorbent was investigated.

INVESTIGATION OF Cr (VI) IONS ADSORPTIVE REMOVAL FROM AQUEOUS SOLUTION ONTO TiO2-AC COMPOSITE: NON-LINEAR EQUILIBRIUM MODELING AND KINETICS.

2021 ◽  
Vol 10 (1) ◽  
pp. 41-54
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Solution Concentration ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Batch Mode ◽  
Non Linear

The present work dedicated to the removal of Cr(VI) ions in aqueous solution onto a synthetized TiO2-AC composite. Composite characterization was carried out by determining of the point of zero charge pHpzc, iodine number, methylene blue index and FT-IR spectra. Adsorption experiments were conducted in batch mode and the influences of composite quantity, contact time, Cr(VI) ions concentration, ionic strength, and pH were studied. The highest adsorption were obtained in acid medium, with lowest adsorbent quantity (0.01 g) and initial solution concentration of 10 ppm. The results of kinetic studies revealed that Cr(VI) adsorption process on TiO2-AC composite followed pseudo second-order kinetic model. Non-linear regression was applied to equilibrium data and Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models were used for evaluation of adsorption parameters. The best-fitting was estimated based on correlation coefficient R2 value and the calculation of error deviations between experimental and predicted equilibrium adsorption data, using non-linear analysis. The results showed that Freundlich model describing adsorption process the best. The isotherm parameters from Langmuir and Freundlich models revealed that Cr(VI) adsorption mechanism on the composite is linear, spontaneous, and endothermic follows chemisorption process.

Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Selective Removal ◽  
Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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.

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

scholarly journals An Investigation into the Adsorption of Aniline from Aqueous Solution Using H-Beta Zeolites and Copper-Exchanged Beta Zeolites

2005 ◽  
Vol 23 (3) ◽  
pp. 255-266 ◽  
Author(s):  
J. O'Brien ◽  
T. Curtin ◽  
T.F. O'Dwyer
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Zeolite Beta ◽  
Langmuir Model ◽  
Beta Zeolite ◽  
Copper Leaching ◽  
Beta Zeolites ◽  
The Stability ◽  
Ph Range ◽  
Adsorbent Materials

Zeolite beta, a large-pore zeolite, was investigated in this study with a view to examining it as a potential adsorbent for the removal of aniline from aqueous solutions. Two different metal-loaded zeolites were prepared by exchanging H-beta zeolite (SiO2/Al2O3 = 75:1) with copper. The influence of exchanged copper on the uptake level was assessed. The effect of varying the silica-to-alumina ratio of the H-beta zeolite on the aniline uptake level was also examined, using three different H-beta zeolites with ratios of 25:1, 75:1 and 150:1 as adsorbents. The sorption experiments indicated an uptake level of ca. 110–120 mg/g for each zeolite and this level was also adsorbed by the copper-modified H-beta zeolites (SiO2/Al2O3 = 75:1). In all cases, the adsorption process followed the Langmuir model for adsorption and the level of aniline adsorbed was largely unaffected by a change in temperature or the presence of extra framework copper. The stability of the exchanged copper on these zeolites was then examined by measuring the quantity of copper leached from each zeolite into solution as a function of pH. Minimum copper leaching was observed in the pH range 5–11. This provided a stable pH working range for the adsorbent materials.

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