Effects of Adsorbed Water Vapor on the Adsorption Rate Constant and the Kinetic Adsorption Capacity of the Wheeler Kinetic Model

AIHAJ ◽  
1988 ◽  
Vol 49 (9) ◽  
pp. 461-465 ◽  
Author(s):  
THOMAS HALL ◽  
PATRICK BREYSSE ◽  
MORTON CORN ◽  
L.A. JONAS
Keyword(s):  
Water Vapor ◽  
Kinetic Model ◽  
Adsorption Capacity ◽  
Rate Constant ◽  
Adsorbed Water ◽  
Adsorption Rate ◽  
Kinetic Adsorption ◽  
Adsorption Rate Constant

scholarly journals EFFECT OF DIATOMEAOUS EARTH TREATMENT USING HYDROGEN CHLORIDE AND SULFURIC ACID ON KINETICS OF CADMIUM(II) ADSORPTION

2010 ◽  
Vol 2 (2) ◽  
pp. 107-112
Author(s):  
Nuryono Nuryono ◽  
Narsito Narsito
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Hydrogen Chloride ◽  
Rate Constant ◽  
Diatomaceous Earth ◽  
Adsorption Rate ◽  
Physical Interaction ◽  
First Order ◽  
Adsorption Rate Constant ◽  
Kinetics Of

In this research, treatment of diatomaceous earth, Sangiran, Central Java using hydrogen chloride (HCl) and sulfuric acid (H2SO4) on kinetics of Cd(II) adsorption in aqueous solution has been carried out. The work was conducted by mixing an amount of grounded diatomaceous earth (200 mesh in size) with HCl or H2SO4 solution in various concentrations for two hours at temperature range of 100 - 150oC. The mixture was then filtered and washed with water until the filtrate pH is approximately 7 and then the residue was dried for four hours at a temperature of 70oC. The product was used as an adsorbent to adsorb Cd(II) in aqueous solution with various concentrations. The Cd(II) adsorbed was determined by analyzing the rest of Cd(II) in the solution using atomic absorption spectrophotometry. The effect of treatment was evaluated from kinetic parameter of adsorption rate constant calculated based on the simple kinetic model. Results showed  that before equilibrium condition reached, adsorpstion of Cd(II) occurred through two steps, i.e. a step tends to follow a reaction of irreversible first order  (step I) followed by reaction of reversible first order (step II). Treatment with acids, either hydrogen chloride or sulfuric acid, decreased adsorption rate constant for the step I from 15.2/min to a range of 6.4 - 9.4/min.  However, increasing concentration of acid (in a range of concentration investigated) did not give significant and constant change of adsorption rate constant. For step II process,  adsorption involved physical interaction with the sufficient low adsorption energy (in a range of 311.3 - 1001 J/mol).     Keywords: adsorption, cdmium, diatomaceous earth, kinetics.

Adsorption Isotherm and Kinetics of Water Vapor Adsorption Using Novel Super-Porous Hydrogel Composites

2020 ◽  
Author(s):  
Hemant Mittal ◽  
Ali Al-Alili ◽  
Saeed M. Alhassan
Keyword(s):  
Water Vapor ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Polymer Matrix ◽  
Adsorbed Water ◽  
Water Vapor Adsorption ◽  
Water Molecules ◽  
Vapor Adsorption ◽  
Highly Effective ◽  
Desiccant Material

Abstract Deliquescent salts have high water vapor adsorption capacity, but they dissolve in water by forming crystalline hydrates. That restricts their use in different water vapor adsorption applications. However, this limitation can be overcome by incorporating deliquescent salts within a polymer matrix which will keep the salt solution in place. Furthermore, if the polymer matrix used is also capable of adsorbing water vapor, it will further improve the overall performance of desiccant system. Therefore, in this work, we are proposing the synthesis and use of a highly effective new solid polymer desiccant material, i.e. superporous hydrogel (SPHs) of poly(sodium acrylate-co-acrylic acid (P(SA-co-AA)), and subsequently its composite with deliquescent salt, i.e. calcium chloride (CaCl2), to adsorb water vapors from humid air without the dissolution of the salt in the adsorbed water. Parental PAA-SPHs matrix alone exhibited an adsorption capacity of 1.02 gw/gads which increased to 3.35 gw/gads after incorporating CaCl2 salt in the polymer matrix. Both materials exhibited type-III adsorption isotherm and the experimental isotherm data fitted to the Guggenheim, Anderson and Boer (GAB) isotherm model. However, the adsorption kinetics followed linear driving force model which suggested that this extremely high adsorption capacity was due to the diffusion of water molecules into the interconnected pores of SPHs via capillary channels followed by the attachment of adsorbed water molecules to the CaCl2 salt present in the polymer matrix. Furthermore, the adsorbents were used successively for six cycles of adsorption with a very little loss in adsorption capacity. Therefore, the proposed polymer desiccant material overcomes the problem of dissolution of deliquescent salts and opens the doors for a new class of highly effective solid desiccant material.

Kinetics and Adsorption Ions of Heavy Metal by Modified Alumino-Silicates

2021 ◽  
Vol 316 ◽  
pp. 170-174
Author(s):  
Elena G. Filatova ◽  
Yury N. Pozhidaev
Keyword(s):  
Heavy Metal ◽  
Rate Constant ◽  
Heavy Metal Ions ◽  
Second Order ◽  
Adsorption Rate ◽  
Order Model ◽  
Adsorption Rate Constant ◽  
Maximum Value ◽  
Pseudo Second Order ◽  
Kinetics Of

Adsorption isotherms of Ni (II) and Cu (II) ions by alumino-silicates, modified with N, N'-bis (3-triethoxysilylpropyl) thiocarbamide (BTM-3), and HCl, were obtained. The adsorption kinetics of heavy metal ions is studied, using the kinetic pseudo-first and pseudo-second order models. It is shown that, when alumino-silicates are modified, the rate and energy of adsorption increase. It is established that the kinetics of the adsorption of the studied ions is best described by a pseudo-second order model. The maximum value of the adsorption rate constant of 33.7∙10-5 g/ (mmol min) corresponds to nickel (II) ions for alumino-silicates, modified with HCl. The maximum value of the adsorption rate constant value of 2.91∙10-5 g/ (mmol min) for alumino-silicates, modified with BTM-3, corresponds to Cu (II) ions.

scholarly journals ADSORPTION OF BACTERIOPHAGE UNDER VARIOUS PHYSIOLOGICAL CONDITIONS OF THE HOST

1940 ◽  
Vol 23 (5) ◽  
pp. 631-642 ◽  
Author(s):  
M. Delbrück
Keyword(s):  
Rate Constant ◽  
Physiological State ◽  
Adsorption Rate ◽  
Bacterial Host ◽  
Physiological Conditions ◽  
Adsorption Rate Constant ◽  
Assay Methods ◽  
Free Phage

1. The adsorption rate constant of phage to bacterium is found to change between wide limits, depending on the physiological state of the bacterium. 2. The experiments of Krueger and of Schlesinger on the residual free phage in contact with an excess of bacteria are discussed and the view of Schlesinger, that they represent phage particles with reduced affinity to the bacterial host is supported by experiments. 3. The theory of von Smoluchowski and Schlesinger is compared with the experiments. 4. The implications of these findings for the assay methods currently used are discussed.

A Study on Surfactant Adsorption Kinetics:  Effect of Bulk Concentration on the Limiting Adsorption Rate Constant

Langmuir ◽  
2000 ◽  
Vol 16 (10) ◽  
pp. 4573-4580 ◽  
Author(s):  
Chengdi Dong ◽  
Ching-Tien Hsu ◽  
Chin-Yuan Chiu ◽  
Shi-Yow Lin
Keyword(s):  
Rate Constant ◽  
Adsorption Kinetics ◽  
Adsorption Rate ◽  
Surfactant Adsorption ◽  
Bulk Concentration ◽  
Adsorption Rate Constant

scholarly journals A Simple Method for Calculating the Overall Adsorption Rate Constant in the Wheeler–Jonas Equation

2011 ◽  
Vol 29 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Chongyang Zhou ◽  
Shujuan Feng ◽  
Gouqing Zhou ◽  
Yuren Jin ◽  
Junfu Liang ◽  
...  
Keyword(s):  
Rate Constant ◽  
Adsorption Rate ◽  
Simple Method ◽  
Adsorption Rate Constant

scholarly journals A Novel Stoichio-Kinetic Model for the DPPH• Assay: The Importance of the Side Reaction and Application to Complex Mixtures

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1019
Author(s):  
Lucrezia Angeli ◽  
Sebastian Imperiale ◽  
Yubin Ding ◽  
Matteo Scampicchio ◽  
Ksenia Morozova
Keyword(s):  
Antioxidant Activity ◽  
Kinetic Model ◽  
Rate Constant ◽  
High Resolution Mass Spectrometry ◽  
Sinapic Acid ◽  
Side Reaction ◽  
Main Reaction ◽  
Dpph Assay ◽  
Best Fitting ◽  
The Common

The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay is widely used to determine the antioxidant activity of food products and extracts. However, the common DPPH• protocol uses a two-point measurement and does not give information about the kinetics of the reaction. A novel stoichio-kinetic model applied in this study monitors the consumption of DPPH• by common antioxidants following the second order reaction. The fitting of such decay yields the rate constant k1, which describes the main reaction between antioxidants and DPPH•, and the rate constant k2, which is attributed to a slower side reaction considering the products generated between the transient radicals (AO•) and another molecule of DPPH•. The model was first applied to antioxidant standards. Sinapic acid, Trolox and ascorbic and chlorogenic acids did not show any side reaction. Instead gallic, ferulic and caffeic acids achieved the best fitting with k2. The products of the side reaction for these compounds were confirmed and identified with high-resolution mass spectrometry. Finally, the kinetic model was applied to evaluate the antioxidant activity of eight herbal extracts. This study suggests a new kinetic approach to standardize the common DPPH• assay for the determination of antioxidant activity.

scholarly journals KINETIC STUDY ON ADSORPTION OF CHROMIUM(lIl) TO DIATOMACEOUS EARTH PRE-TREATED WITH SULFURIC AND HYDROCHLORIC ACIDS

2010 ◽  
Vol 3 (1) ◽  
pp. 32-38
Author(s):  
Nuryono Nuryono ◽  
V.V.H. Susanti ◽  
Narsito Narsito
Keyword(s):  
Rate Constant ◽  
Adsorption Kinetics ◽  
Diatomaceous Earth ◽  
Atomic Absorption Spectrophotometry ◽  
Adsorption Rate ◽  
Physical Interaction ◽  
Kinetics Of Adsorption ◽  
Pre Treatment ◽  
Sulfuric And Hydrochloric Acids ◽  
Kinetics Of

In this research, the effect of Sangiran diatomaceous earth pre-treatment with sulfuric acid (H2SO4) and hydrochloric acid (HCl) on the kinetics of adsorption for Cr(III) in aqueous solution has been studied. The research has been carried out by mixing an amount of diatomeaeous earth with HCl or H2SO4 in various concentrations for two hours at temperature of 150 - 200°C. The mixture was washed with water until neutral, and the residue was dried at 70°C for four hours. The result then was used as adsorbent. Adsorption was carried out by mixing an amount of adsorbent with Cr(III) solution in various contact times. Ion adsorbed was determined by analyzing filtrate using atomic absorption spectrophotometry. The effect of pre-treatment on adsorption kinetics was evaluated based on kinetic parameters, i.e. constant of adsorption rate by using Langmuir-Hinshelwood kinetics and using two-process kinetics (fast and slow processes). Adsorption kinetics calculated using LH equation gave negative value for adsorption rate constant of zero order (k0). On the other words, the LH kinetics might not be applied for adsorption of Cr(III) to diatomaceous earth adsorbent. Results of kinetics study approached using two processes (fast and slow) showed that adsorption of Cr(III) occurred in two processes with rate constant of fast adsorption, kc, 0.041/min, rate constant of slow adsorption, kl, 0.0089/min, and of slow desorption, k'l, 0.089/menit. Pre-treatment with HCl up to 10 M decreased either kc, kl or k'l, while pre-treatment with H2SO4 1M increased kc to 0.061/min, decreased kl to 0.00424 and k'l to 0.0139/min. On pre-treatment with H2SO4 higher than 6 M significantly decreased three constants above. Based on the Gibbs energy change (4.31 - 6.79 kJ/mole) showed that adsorption involved physical interaction.   Keywords: adsorption, chromium, diatomaceous earth, kinetics, Langmuir-Hinshelwood

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