Theoretical prediction of gas adsorption kinetics based on equilibrium data

2012 ◽  
Vol 90 (10) ◽  
pp. 828-835 ◽  
Author(s):  
Krzysztof Nieszporek ◽  
Tomasz Banach
Keyword(s):  
Theoretical Model ◽  
Theoretical Prediction ◽  
Intermolecular Interactions ◽  
Adsorption Kinetics ◽  
Gas Adsorption ◽  
Rate Equations ◽  
Equilibrium Isotherm ◽  
Energetic Heterogeneity ◽  
Equilibrium Data ◽  
Adsorption Systems

Based on the equilibrium adsorption isotherms, new expressions describing the rate of adsorption were developed. The theoretical model takes into account the influence of diffusional effects on the rate of adsorption. Other nonideal effects such as surface energetic heterogeneity or intermolecular interactions can be taken into account by using the adequate equilibrium isotherm. The accuracy of the presented rate equations was verified using real adsorption systems.

Studies relating to an electrochemically assisted coagulation for the removal of chromium from water using zinc anode

2011 ◽  
Vol 11 (2) ◽  
pp. 142-150 ◽  
Author(s):  
S. Vasudevan ◽  
J. Lakshmi
Keyword(s):  
Adsorption Kinetics ◽  
Current Density ◽  
Second Order ◽  
Rate Equations ◽  
Zinc Anode ◽  
Effects Of Ph ◽  
Equilibrium Data ◽  
Density Concentration ◽  
Chromium Adsorption ◽  
Kinetics And Isotherms

In this work, an electrochemically assisted coagulation for the removal of chromium from water has been studied using zinc as anode and galvanized iron as cathode. The effects of pH, current density, concentration of chromium, temperature, adsorption kinetics and isotherms on the removal of chromium were investigated. The results showed that the optimum removal efficiency of 96.5% was achieved at a current density of 0.2 A/dm2, at a pH of 7.0. First- and second-order rate equations, Elovich and intraparticle diffusion models were applied to study adsorption kinetics. The adsorption process follows second-order kinetics model with good correlation. An equilibrium isotherm was measured experimentally and the results were analyzed by the Langmuir, Freundlich and Dubinin-Redushkevich model using linearized correlation co-efficient. The Langmuir adsorption isotherm was found to fit the equilibrium data for chromium adsorption. Temperature studies showed that the adsorption was endothermic and spontaneous in nature.

Assessment of surface energetic heterogeneity of synthetic Na- saponites. The role of layer charge

Clay Minerals ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 39-57 ◽  
Author(s):  
L. J. Michot ◽  
F. Villiéras
Keyword(s):  
Aspect Ratio ◽  
Gas Adsorption ◽  
High Energy ◽  
Layer Charge ◽  
Adsorption Mechanisms ◽  
Energetic Heterogeneity ◽  
Complex Adsorption ◽  
Adsorption Energy Distribution ◽  
Synthetic Saponite

AbstractHigh-resolution gas adsorption techniques were used to analyse the evolution of the aspect ratio and adsorption energy distribution on synthetic saponite samples with increasing layer charge. Using Ar as a gaseous probe, the aspect ratio of the saponite particles can be determined easily by decomposing the derivative adsorption isotherms and taking into account high-energy sites which can be assigned to talc-like ditrigonal cavities. Changes in the shape of the elementary particles are observed for layer charges above 1.30, i.e. when all the ditrigonal cavities contain at least one Al atom substituting for Si. When N2 is used as a probe, high-energy sites that could be wrongly interpreted as micropores on the basis of classical t-plot treatments are observed whatever the layer charge. Using the information obtained from both Ar and N2, schemes for describing adsorption can be proposed for all layer charges and suggest complex adsorption mechanisms for charged clay minerals.

scholarly journals Comparison of adsorptions by rice hull and Lewatit TP 214 of platinum in chloride solution

2013 ◽  
Vol 78 (6) ◽  
pp. 811-826 ◽  
Author(s):  
M.H. Morcali ◽  
B. Zeytuncu ◽  
O. Yucel
Keyword(s):  
Waste Product ◽  
Second Order ◽  
Attenuated Total Reflection ◽  
Rate Equations ◽  
Rice Hull ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Biomass Waste ◽  
Equilibrium Data ◽  
Pseudo Second Order

Rice hull, a biomass waste product, and Lewatit TP 214, a thiosemicarbazide sorbent, were investigated as adsorbents for the adsorption of platinum (IV) ions from synthetically prepared dilute chloroplatinic acid solutions. The rice hull was characterized by Attenuated Total Reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The effects of the different adsorption parameters, sorbent dosage, contact time, temperature and pH of solution on adsorption percentage were studied in detail on a batch sorption. The adsorption equilibrium data were best fitted with the Langmuir isotherm model. The maximum monolayer adsorption capacities, Qmax, at 25?C were found to be 42.02 and 33.22 mg g-1 for the rice hull and Lewatit TP 214, respectively. Thermodynamic calculations using the measured ?H?, ?S? and ?G? values indicate that the adsorption process was spontaneous and exothermic. The pseudo-first-order and pseudo-second-order rate equations were investigated; the adsorption of platinum ions for both sorbents was found to be described by the pseudo-second-order kinetic model. The kinetic rate, k2, using 30 mg sorbent at 25?C was found to be 0.0289 and 0.0039 g min-1 mg-1 for the rice hull and Lewatit TP 214, respectively. The results indicated that the rice hull can be effectively used for the removal of platinum from aqueous solution.

Adsorption Kinetics and Surface Characterization of Microorganisms Grown under Different Conditions

2015 ◽  
Vol 1130 ◽  
pp. 519-523
Author(s):  
Zeng Ling Wu ◽  
Wei Zhang Kong ◽  
Jin Yan Liu ◽  
Zhi Wu ◽  
Shui Ping Zhong ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Surface Characterization ◽  
Elemental Sulfur ◽  
Selective Adsorption ◽  
Copper Concentrate ◽  
Freundlich Isotherms ◽  
Equilibrium Data ◽  
Ft Ir ◽  
Mixed Bacteria ◽  
Adsorption Equilibrium Data

The adsorption of bacteria onto minerals is the premise for bioleaching and plays an important role in minerals oxidation. Understanding of the adsorption kinetics onto the surface will give information on the effectiveness of bioleaching. Three kinds of mixed bacteria (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, Sulfobacillus) were cultured in different substrates - copper concentrate, elemental sulfur and ferrous iron and adsorbed onto different solid surface of elemental sulfur, silica and copper concentrate. Adsorption kinetics was examined and surface properties were investigated by Zeta-potential and FT-IR spectroscopy. Bacterial adsorption equilibrium data for bacteria grown on three different substrates were well fitted to Freundlich isotherms, indicating inhomogeneous and selective adsorption. Microorganisms grown on copper concentrate and S0 showed similar adsorption kinetics whereby cell adsorptions proceeded rapidly and reached equilibrium within 30 mins of interaction. With the average KF value of 46.2, most copper concentrate-grown cells were strongly adsorbed to three solid surfaces. Microorganisms grown on copper concentrate and S0 also showed higher hydrophobicity and higher isoelectric point (IEP) (pH 3.4-3.8) as compared to the soluble Fe2+-grown cells (pH 2.1), indicating higher amount of EPS and proteins on the surfaces. The FT-IR spectra indicated the presence of COOH, NH2, OH and PO4 groups on all cell surfaces. However, more proteinaceous compounds were found on cells grown on copper concentrate and S0 substrates.

Effects of energetic heterogeneity on gas adsorption and gas storage in geologic shale systems

2019 ◽  
Vol 251 ◽  
pp. 113368 ◽  
Author(s):  
Jing Li ◽  
Keliu Wu ◽  
Zhangxin Chen ◽  
Wenyang Wang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Gas Storage ◽  
Energetic Heterogeneity

scholarly journals First-Principles Investigation of the Adsorption Behaviors of CH2O on BN, AlN, GaN, InN, BP, and P Monolayers

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 676 ◽  
Author(s):  
Chuang Feng ◽  
Hongbo Qin ◽  
Daoguo Yang ◽  
Guoqi Zhang
Keyword(s):  
Charge Transfer ◽  
First Principles ◽  
Gas Adsorption ◽  
Indium Nitride ◽  
Single Layer ◽  
Boron Phosphide ◽  
Adsorption Behaviors ◽  
Gas Molecule ◽  
Adsorption Energies ◽  
Adsorption Systems

CH2O is a common toxic gas molecule that can cause asthma and dermatitis in humans. In this study the adsorption behaviors of the CH2O adsorbed on the boron nitride (BN), aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), boron phosphide (BP), and phosphorus (P) monolayers were investigated using the first-principles method, and potential materials that could be used for detecting CH2O were identified. The gas adsorption energies, charge transfers and electronic properties of the gas adsorption systems have been calculated to study the gas adsorption behaviors of CH2O on these single-layer materials. The electronic characteristics of these materials, except for the BP monolayer, were observed to change after CH2O adsorption. For CH2O on the BN, GaN, BP, and P surfaces, the gas adsorption behaviors were considered to follow a physical trend, whereas CH2O was chemically adsorbed on the AlN and InN monolayers. Given their large gas adsorption energies and high charge transfers, the AlN, GaN, and InN monolayers are potential materials for CH2O detection using the charge transfer mechanism.

Sign in / Sign up

Export Citation Format

Share Document