Kinetic Studies of Adsorption Process of Zambian Kapiri Mposhi Zeolites

2021 ◽  
Vol 37 (2) ◽  
pp. 467-475
Author(s):  
Marina G. Xavier

Batch adsorption studies were done on aqueous solutions of Pb(NO3)2 at varying solute concentration, adsorbent dose, contact time, temperature, calcination temperatures and pH. Residual concentrations of the solute were found out using AAS and optimum conditions were studied. Adsorbent used in this study is locally available silicate rich mineral which closely resembles zeolites. The net negative charge on the framework of hydrated aluminosilicates is responsible for ion exchange property. Freundlich model was used to validate the results obtained from batch experiments plotting lnCe vs lnqe. Objective of this work is to study the kinetics of adsorption considering the interplay of particle diffusion in addition to proving the effectiveness as an adsorbent. A diffusion model also was also applied apart from kinetic model to analyze the experimental results more specifically. For maximizing the efficiency of the adsorption process and minimizing the time involved, variables like temperature, reactants and pH were manipulated using kinetic studies. It establishes the optimum reaction conditions for various experimental parameters in the process of adsorption.

2021 ◽  
Vol 12 (2) ◽  
pp. 156-162
Author(s):  
A.S. Muhammad ◽  
M.A. Abdurrahman

A batch adsorption process was carried out by optimizing, the effect of contact time (10min to 180min) and initial concentration (5mg/l to150mg/l). The adsorbent was characterized using FTIR spectra and SEM, and the result obtained showed shifting and disappearance of peaks after adsorption. The results of the adsorption kinetics, which includes the correlation coefficient 0.9771 and the agreement between the amount adsorbed experimentally (1.472mg/g) and the calculated amount absorbed(1.196mg/g) revealed that MB was adsorbed satisfactory according to the pseudo second-order kinetic model.


2017 ◽  
Vol 13 (27) ◽  
pp. 425
Author(s):  
Azeh Yakubu ◽  
Gabriel Ademola Olatunji ◽  
Folahan Amoo Adekola

This investigation was conducted to evaluate the adsorption capacity of nanoparticles of cellulose origin. Nanoparticles were synthesized by acid hydrolysis of microcrystalline cellulose/cellulose acetate using 64% H3PO4 and characterized using FTIR, XRD, TGA-DTGA, BET and SEM analysis. Adsorption kinetics of Pb (II) ions in aqueous solution was investigated and the effect of initial concentration, pH, time, adsorbent dosage and solution temperature. The results showed that adsorption increased with increasing concentration with removal efficiencies of 60% and 92.99% for Azeh2 and Azeh10 respectively for initial lead concentration of 3 mg/g. The effects of contact time showed that adsorption maximum was attained within 24h of contact time. The maximum adsorption capacity and removal efficiency were achieved at pH6. Small dose of adsorbent had better performance. The kinetics of adsorption was best described by the pseudo-second-Order model while the adsorption mechanism was chemisorption and pore diffusion based on intra-particle diffusion model. The isotherm model was Freundlich. Though, all tested isotherm models relatively showed good correlation coefficients ranging from 0.969-1.000. The adsorption process was exothermic for Azeh-TDI, with a negative value of -12.812 X 103 KJ/mol. This indicates that the adsorption process for Pb by Azeh-TDI was spontaneous. Adsorption by Azeh2 was endothermic in nature.


2016 ◽  
Vol 113 (41) ◽  
pp. 11465-11470 ◽  
Author(s):  
Birte Riechers ◽  
Florine Maes ◽  
Elias Akoury ◽  
Benoît Semin ◽  
Philipp Gruner ◽  
...  

Emulsions are metastable dispersions. Their lifetimes are directly related to the dynamics of surfactants. We design a microfluidic method to measure the kinetics of adsorption of surfactants to the droplet interface, a key process involved in foaming, emulsification, and droplet coarsening. The method is based on the pH decay in the droplet as a direct measurement of the adsorption of a carboxylic acid surfactant to the interface. From the kinetic measurement of the bulk equilibration of the pH, we fully determine the adsorption process of the surfactant. The small droplet size and the convection during the droplet flow ensure that the transport of surfactant through the bulk is not limiting the kinetics of adsorption. To validate our measurements, we show that the adsorption process determines the timescale required to stabilize droplets against coalescence, and we show that the interface should be covered at more than 90% to prevent coalescence. We therefore quantitatively link the process of adsorption/desorption, the stabilization of emulsions, and the kinetics of solute partitioning—here through ion exchange—unraveling the timescales governing these processes. Our method can be further generalized to other surfactants, including nonionic surfactants, by making use of fluorophore–surfactant interactions.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Swarup Biswas ◽  
Umesh Mishra

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Benias C. Nyamunda ◽  
Terrence Chivhanga ◽  
Upenyu Guyo ◽  
Fidelis Chigondo

This study evaluates the effectiveness of magnetic biochar (Fe2O3-EC) derived from water hyacinth in the removal of Cu+2 and Zn+2 from aqueous solution. Fe2O3-EC was prepared by chemical coprecipitation of a mixture of FeCl2 and FeCl3 on water hyacinth biomass followed by pyrolysis. The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDX). Batch adsorption studies on the effects of temperature, biosorbent dosage, contact time, and initial metal ion concentration were carried out. Fe2O3-EC exhibited optimum contact time, biosorbent dosage, and pH values of 65 min, 1.2 g, and 6, respectively. Fe2O3-EC exhibited strong magnetic separation ability and high sorption capability. Metal ion adsorption onto the biochar conformed to the Langmuir isotherm. Kinetic studies revealed that the adsorption process followed pseudo-second-order model. The calculated thermodynamic parameters showed that the adsorption process was feasible and exothermic in nature. These results have demonstrated that the use of Fe2O3-EC in metal ion removal could provide an alternative way to manage and utilize this highly problematic invasive species.


2020 ◽  
Vol 15 (3) ◽  
pp. 765-785
Author(s):  
Taibi Mohamed ◽  
Elaziouti Abdelkader ◽  
Laouedj Nadjia ◽  
Dellal Abdelkader

The RM (RM stands for the pristine clay) collected from sites in the Naima-Tiaret-Algeria and its purified phase TM (TM stands for the treated clay) were characterized using XRF, XRD, FT−IR, SEM−EDX, and DC electrical conductivity techniques. The as-prepared clays were used as potential adsorbents for the removal of Cu2+ and Zn2+ metals ions. Highly purified clay TM, exhibiting a basal, spacing of 25.83 Å and CEC of 51 meq/100 g, was obtained. The type of interstratified I/M in the studied sites is S=1, based on the calculation method of Watanabe. The percentage of illite type S=1 is between 80−85% illite. The adsorption equilibrium was established in 60 min with the capacities of 28.57 and 24.39 mg/g for Cu2+ onto RM, 32.25 and 4.95 mg/g for Zn2+ in the presence of TM. D-R isotherm model was more suitable with the adsorption process than Freundlich and Langmuir models suggesting the ion exchange nature of the retention mechanism in most cases (E > 8 kJ/mol). Pseudo second-order model best described the kinetics of adsorption process. The adsorption mechanism was mainly monitored by ion exchange mechanism between exchangeable interlayer cations (Na) in the interstratified I/M and Cu2+ or Zn2+ metals from aqueous matrix. Further, the release of H+ ions from the edge of the layer structure in acidic environments promote the adsorption of heavy metals onto the surfaces interstratified I/M clay soils via electrostatic attraction. Copyright © 2020 BCREC Group. All rights reserved 


BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 121-143
Author(s):  
Shree P. Mishra ◽  
Jennifer Thirree ◽  
Anne-S. Manent ◽  
Bruno Chabot ◽  
Claude Daneault

In this study application of ultrasound in oxidizing native cellulose for the production of nanocellulose has been explored for the first time. Bleached hardwood kraft pulp was oxidized with an ultrasound (US) catalyzed 2,2,6,6-tetramethylepiperidin-1-oxyl (TEMPO) system (US-TEMPO-system) at five different temperatures – 5, 15, 25, 35, and 45°C and two pH ranges, 8.5-9.0 and 10.0-10.5 – to obtain the optimum reaction conditions. The reaction pH and temperature have significant effect on the kinetics of the formation of carboxylate in the oxidized pulps and produce depolymerization at temperatures greater than 25°C. Formation of carboxylate on the cellulose chain is directly proportional to the NaBr concentration. The pulp oxidized by the US-TEMPO-system at 25°C had 10-15% more carboxyls and showed a ca. 10% increase in the nanocellulose yield when compared to the TEMPO-system without sono-catalysis.


2019 ◽  
Vol 8 (2) ◽  
pp. 79-84
Author(s):  
Bode Haryanto ◽  
Warren K Sinaga ◽  
Febri T Saragih

This study aimed to analyze the adsorption ability of black sand in the metal ions adsorb cadmium (Cd2+) with a concentration of 70 ppm to a solution with a pH of 4,5. The black sand is used is 40 mesh. This research was conducted by batch adsorption system naturally and adsorption kinetics modeling. Kinetics of adsorption reached equilibrium at time t = 120 minutes with the percentage concentration of adsorbed Cd2+ 18,5%. In the adsorption kinetics modeling correlation coefficient is almost the same between the equations of first order and second order in the amount of 0.98 and 0.99. The result indicated that the type of interaction Cd2+ ions on the surface of black sands occur in chemistry and physics. The adsorption kinetics of diffusion modeling of internal and external diffusion of the correlation coefficient of 0,85 and 0,71. From this data it can be seen that in this study is modeling kinetic internal diffusion trend that shows adsorbent particles are inter sand surface area that experienced internal inter-particle pore diffusion.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Felix A. Aisien ◽  
Andrew N. Amenaghawon ◽  
Albert I. Adinkwuye

The potential use of waste tyre rubber granules (WTRG) for the batch adsorption of naphthalene from aqueous solutions was investigated. The effect of various operational variables such as contact time, initial naphthalene concentration, adsorbent dose, size of adsorbent particles, and temperature of solution on the adsorption capacity of WTRG was evaluated. The adsorption of naphthalene by WTRG was a fast kinetic process with an equilibrium contact time of 60 min. A low temperature (5°C), small adsorbent particle size (0.212 mm) and higher adsorbent dosage favored the adsorption process. Results of isotherm studies revealed that adsorption of naphthalene was best described by the Langmuir isotherm equation (R<sup>2</sup>=0.997) while the kinetics of the process was best described by the Lagergren pseudofirst order kinetic equation (R<sup>2</sup>=0.998). This study has demonstrated the suitability of WTRG for the removal of naphthalene from aqueous solution.


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