scholarly journals Adsorption Kinetic Behaviour of Pure CO2, N2 and CH4 in Natural Clinoptilolite at Different Temperatures

2003 ◽  
Vol 21 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Gelacio Aguilar-Armenta ◽  
María E. Patiño-Iglesias ◽  
Roberto Leyva-Ramos

The adsorption kinetics of pure CO2, N2 and CH4 on a natural clinoptilolite (ZSL) sample from Villa de Reyes (San Luis Potosí, México) were measured at different temperatures using a glass, high-vacuum volumetric system. The ability of the natural zeolite to adsorb these gases depended on the gas–adsorbent contact time, t. For short values of t, the gas adsorption uptakes decreased in the order CO2 >> N2 > CH4. However, for long t values, the adsorption uptakes decreased in the sequence CO2 > CH4 > N2. It was established that the activation energies (kJ/mol) for the adsorption process increased in the following order CO2 (15) < N2 (18) < CH4 (40), correlating fairly well with the increasing order of kinetic diameter (Å) of the molecules: CO2 (3.3) < N2 (3.64) < CH4 (3.8). In comparison to the ZSL sample, the rate of adsorption of N2 and CH4 on H-ZSL increased and the total adsorption capacity decreased. The ZSL sample may be recommended as an effective adsorbent for the separation of CO2/CH4 and N2/CH4 mixtures.

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.


2020 ◽  
Vol 23 (10) ◽  
pp. 370-376
Author(s):  
Thamrin Azis ◽  
La Ode Ahmad ◽  
Keke Awaliyah ◽  
Laode Abdul Kadir

Research on the equilibrium and adsorption kinetics of methylene blue dye using tannin gel from the Tingi tree (Ceriops tagal) has been carried out. This study aims to determine the capacity and adsorption kinetics of tannin gel against methylene blue dye. Several parameters, such as the effect of contact time, pH, and methylene blue dye concentration on adsorption, were also studied. Based on the research results, the optimum adsorption process is a contact time of 30 minutes and a pH of 7. The adsorption capacity increased to a concentration of 80 mg/L with a maximum adsorption capacity (qm) of 49.261 mg/g. The adsorption process follows the pseudo-second-order adsorption kinetics model and the Langmuir isotherm model.


2012 ◽  
Vol 12 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Susy Yunita Prabawati ◽  
Jumina Jumina ◽  
Sri Juari Santosa ◽  
Mustofa Mustofa ◽  
Keisuke Ohto

A research has been conducted to investigate the capability of a series of novel calix[6]arenes-based polymers: poly-monoallyloxycalix[6]arene (2a), poly-monoallyloxypenta-estercalix[6]arene (2b) and poly-monoallyloxypenta-acidcalix[6]arene (2c) for trapping of heavy metal cations such as Cd(II), Cu(II) and Cr(III). The existence of active hydroxy group (-OH) and with a tunnel-like structure of the polymers, caused the polymers can be used as adsorbents for heavy metals. The adsorption process was carried out in batch method in the variation of acidity (pH), contact time and initial concentration of metal ions. The results showed that the amount of adsorbed metal increased with the increasing of the pH of metal solution. For these three polymers, the amount of metal ions Cd(II), Cu(II) and Cr(III) adsorbed was optimum at pH 7, 6 and 5 respectively. The optimum contact time for Cd(II) and Cu(II) was 120 min, while that for Cr(III) was 60 min. Study of the adsorption kinetics showed that the adsorption of Cd(II), Cu(II) and Cr(III) using polymer 2a followed kinetics model of Ho. For adsorbent 2b and 2c, the adsorption kinetics of Cd(II) and Cr(III) also followed kinetics model of Ho while for the Cu(II) followed Lagergren kinetic models. Isothermal studies showed that the adsorption of metal ions on all adsorbents tend to follow the Langmuir isotherm. The adsorption energies of the three adsorbents were higher than 23 kJ/mole and polymer 2c has the largest adsorption capacity for Cr(III).


2020 ◽  
Vol 82 (9) ◽  
pp. 1858-1867
Author(s):  
Huannan Wang ◽  
Dandan Yan ◽  
Huan Zeng ◽  
Jiajie He

Abstract A biochar material made from corncobs was tested for its capability in BTEX adsorption/interception in stormwater filtration systems. Batch experiments were conducted to examine the adsorption kinetics, adsorption isotherms, and adsorption thermodynamics of BTEX onto this biochar. The feasibility of applying this biochar in stormwater filtration was studied by dynamic transport experiments and model simulations. The result showed that this biochar can adsorb BTEX and the adsorption is a thermodynamically spontaneous, and endothermic process. The BTEX adsorption kinetic experiment and adsorption retarded BTEX transport experiment indicated that the BTEX adsorption kinetics can be changed by the driving force between the BTEX concentrations and the active adsorption site as well as the contact time between BTEX and the biochar. In terms of applying this biochar in stormwater filtration, the Monte Carlo uncertainty analysis indicated that the BTEX interception is sensitive to the hydraulic conductivity of the biochar filter and the adsorption kinetics of the biochar material. Although this corncob-made biochar demonstrated effective pollutant adsorption capability, the biochar adsorption capability should be utilized to retain the pollutant long enough for biodegradation to take effect for ultimate pollutant attenuation.


2019 ◽  
Vol 35 (3) ◽  
pp. 1004-1012 ◽  
Author(s):  
Henry Olumayowa Oluwasola ◽  
Jonnie Niyi Asegbeloyin ◽  
Alfred Ezinna Ochonogor ◽  
Julius Udeh Ani ◽  
Collins Ugochukwu Ibeji ◽  
...  

The study investigates the sorption of cadmium (Cd) and lead (Pb) by Nsukka urban soils, a Nigeria soil classified as an ultisol soil of tropics. Laboratory batch technique was utilized to investigate the effect of pH, temperature, contact time, and concentration on the adsorption process. Results showed that adsorption efficiency of the soils for Cd2+ and Pb2+ increased with increase in pH, temperature, and contact time but decreased with increase in concentration. The data from adsorption study was fitted to the Langmuir, Freundlich and Temkin adsorption isotherms, and results revealed that Langmuir isotherm fitted most satisfactorily. On the basis of the obtained maximum adsorption capacity (qmax) from the Langmuir model, the affinity of Cd and Pb for the studied soil was Pb2+ > Cd2+. Pseudo-second order (r2 ≥ 0.995-0.999) best described the kinetics of the sorption process for the metal ions in the soil.


2017 ◽  
Vol 6 (1) ◽  
pp. 1-6
Author(s):  
Cut Raziah ◽  
Zerlinda Putri ◽  
Atika Rahmi Lubis ◽  
Sofyana ◽  
Zuhra ◽  
...  

The presence of Cadmium (Cd) in groundwater is an issue that needs serious handling as it causes problems to human health. The removal of Cadmium (Cd) can be done by various methods such as adsorption, oxidation, filtration, and many more. In this study, the method used was adsorption using Aceh natural zeolite. This process was expected to reduce Cd metal as effectively as possible. The adsorption was conducted by varying contact time, adsorbent dosage, pH and initial concentration of Cd metal. The crystallized Aceh natural zeolite was characterized by X-Ray Fluorescence (XRF) with Si/Al zeolite ratio of 4.36 %. The concentration of Cadmium in water was analyzed by means of Atomic Adsorption Spectrophotometer (AAS) standard AA 630. The results showed that the adsorption of cadmium in water solution by Aceh natural zeolite occurred according to   the Freundlich adsorption model. While the adsorption kinetic from the process was found to be a pseudo second order with k2 value of 1.53.


Author(s):  
Onu Chijioke Elijah ◽  
Oguanobi Nonso Collins ◽  
Okonkwo Callistus Obumneme ◽  
Nnamdi-Bejie Jessica

Background: The adsorptive removal of anionic dye (Bromocresol green) from aqueous solution was investigated using activated carbon prepared from rice husk. Place of Study: The research work took place at Nnamdi Azikiwe Univeristy Awka, Nigeria. Methods: The rice husk which was obtained from rice mills in Awka was activated with tetraoxophosphoric acid and carbonized in a furnace. The adsorption process was investigated by varying the contact time, temperature, dosage, pH and initial concentration in a batch process. Five isotherm models (Langmuir, Freundlich, Temkin, Halsay and Harkin-Jura) were employed in the equilibrium studies. Thermodynamics and kinetics of the adsorption were carried out. Results: The result indicated that increase in contact time, adsorbent dosage and temperature increased the percent uptake of the Bromocresol green dye. Maximum percentage adsorption of about 93% was obtained. Langmuir and Harkin-Jura isotherm models best described the equilibrium data of the adsorption process. Pseudo second-order kinetic model best correlates the kinetics of the experimental data. The thermodynamic study showed that the Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were –2.541 kJ/mol,  -7.401 kJ/mol and –15.52 kJ/mol K respectively. Conclusion: This work has shown that activated carbon prepared from rice husk can be used in adsorptive removal of bromocresol green dye from solution and that the adsorption process was spontaneous and exothermic.


2017 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Przemysław Bartczak ◽  
Tomasz Szatkowski ◽  
Teofil Jesionowski

Abstract We demonstrate here that lignin can be successfully combined with silica to create a multifunctional material with considerable sorption capabilities. Experiments were carried out in which a silica/lignin hybrid was used for the removal of lead(II) ions from water solutions. Adsorption kinetics were also determined and preliminary regeneration tests were performed. The effectiveness of the adsorption process depends on the following parameters: contact time of adsorbent and adsorbate (equilibrium times: 5 min for concentration 25 mg/L, 10 min for 50 and 75 mg/L, 60 min for 100 mg/L), pH (optimal pH = 5) and adsorbent mass. The kinetics of the adsorption of lead(II) ions on the SiO2/lignin biosorbent are best described by a pseudo-second-order model. Adsorption isotherms of lead(II) ions were also determined. The experimental data were found to be in agreement with the Langmuir model, and the maximal sorption capacity of the adsorbent with respect to lead(II) was 89.02 mg/g.


2020 ◽  
Vol 5 (2) ◽  
pp. 63
Author(s):  
Matheis F.J.D.P. Tanasale ◽  
Yusthinus T Male ◽  
Nina B Garium

It has been conducted a research about the utilization waste of tofu as adsorbent of tartrazine dye. Utilization waste of tofu as adsorption because tofu contains protein which has the power adsorption of amino acids that form a zwitter ion. The purpose of this study was to determine the adsorption process and adosrption kinetics model of tartrazine dye by waste of tofu as adsorbent. Making the adsorbent is done by making waste of tofu into powder with a size of 100 mesh. The method used in the analysis of tartrazine dye is using UV-Vis. Adsorption of of tartrazine dye using waste of tofu at concentrations of 50 ppm and a contact time of 80 minutes with weight adsorbent 0.3 g. The two isotherms were used that Langmuir isotherm and Freundlich isotherm, the adsorption studies of tartrazine dye adsorbent waste of tofu follow Freundlich adsorption isotherms with a correlation coefficient (R2) of 94.4%, KF is 0.0026 mg/g and n is 0.5621. Adsorption kinetics of of tartrazine dye adsorbent waste of tofu following the model of adsorption Ho pseudo-second order with a correlation coefficient (R2) of 100%, Xe is 1.7761 mg/g and k2,ads is -0.6550 g/mg minutes. The mechanism adsorption of of tartrazine dye with waste of tofu as adsorbent is chemisorpsi process.


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