Scandium adsorption from sulfuric-chloride solutions with activated carbons

2019 ◽  
pp. 49-55
Author(s):  
Wai Moe Aung ◽  
M. V. Marchenko ◽  
I. D. Troshkina
Keyword(s):  
Correlation Coefficient ◽  
Diffusion Model ◽  
Activated Carbons ◽  
Second Order ◽  
Model Description ◽  
Particle Diffusion ◽  
Diffusion Region ◽  
Chloride Solutions ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

The study covers scandium adsorption in batch conditions by VSK, DAS and PFT activated carbon grades (Russia) of different origin (сoconut shell, аnthracite, thermoset waste, respectively) from sulfuric acid-chloride solutions (pH = 2) simulating the composition of the underground leaching solutions of polymetallic ores. It was found that scandium adsorption by DAS and VSK carbons proceeds with the highest distribution coefficients (133 and 45.8 cm3/g, respectively). Isotherms of scandium adsorption with these carbons are linear and described by the Henry equation with constants 133 ± 21 and 46 ± 7 cm3/g, respectively. A limited solution volume method was used to obtain the integral kinetic curves of scandium adsorption. Their linearization according to the kinetic models of the pseudo-first, pseudo-second order, the Elovich model and the Weber–Morris intra-particle diffusion model indicates that the kinetics of scandium adsorption with VSK carbon having a higher correlation coefficient (0.999) is described using the pseudo-second order model. Description of the kinetic data obtained during the adsorption of scandium with DAS carbon showed that for all the models used the correlation coefficient is low (<0.939), while the highest value is observed when using the intra-particle diffusion model. It was suggested that the scandium adsorption process occurs in the mixed diffusion region. The possibility of scandium elution from VSK and DAS carbons with sodium carbonate solution (10 %) was studied in batch conditions, where the degree of scandium desorption in two stages of elution was 84.0 and 90.4 %, respectively.

scholarly journals Guidelines for general adsorption kinetics modeling

2020 ◽  
Vol 74 (1) ◽  
pp. 65-70
Author(s):  
Bojana Obradovic
Keyword(s):  
Adsorption Kinetics ◽  
Scale Up ◽  
Second Order ◽  
Particle Diffusion ◽  
Analysis And Evaluation ◽  
Inappropriate Use ◽  
Adsorption Processes ◽  
Intra Particle Diffusion ◽  
Elovich Equation ◽  
Pseudo Second Order

Adsorption processes are widely used in different technological areas and industry sectors, thus continuously attracting attention in the scientific research and publications. Design and scale-up of these processes are essentially based on the knowledge and understanding of the adsorption kinetics and mechanism. Adsorption kinetics is usually modeled by using several well-known models including the pseudo-first and pseudo-second order models, the Elovich equation, and the intra-particle diffusion based models. However, in the scientific literature there are a significant number of cases with the inappropriate use of these models, utilization of erroneous expressions, and incorrect interpretation of the obtained results. This paper is especially focused on applications of the pseudo-second order, intra-particle diffusion and the Weber-Morris models, which are illustrated with typical examples. Finally, general recommendations for selection of the appropriate kinetic model and model assumptions, data regression analysis, and evaluation and presentation of the obtained results are outlined.

Application of the intra-particle diffusion model for activated carbon fibers in an aqueous medium

2012 ◽  
Vol 1373 ◽  
Author(s):  
Teresa Ramírez-Rodríguez ◽  
Fray de Landa Castillo-Alvarado
Keyword(s):  
Activated Carbon ◽  
Diffusion Model ◽  
Carbon Fibers ◽  
Aqueous Media ◽  
Particle Diffusion ◽  
Activated Carbon Fibers ◽  
Kinetics Of Adsorption ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Kinetics Of

ABSTRACTThe intra-particle diffusion model (IPD), proposed by Weber and Morris has been applied to the analysis of the kinetics of adsorption on activated carbon fibers with phosphate groups in the removal of cadmium ions in aqueous media. It is evident that the removal of cadmium ion kinetic model of pseudo-second order provides a better fit than the model of pseudo-first order and the intra-particle diffusion model provides the best to the sample compared activating solution: grams fibers of 1:3.

Adsorptive Removal of Phosphate from Groundwater Using Granular Activated Carbon

2017 ◽  
Vol 32 ◽  
pp. 53-61 ◽  
Author(s):  
Abdelkader Ouakouak ◽  
Leila Youcef ◽  
Djihad Boulanouar ◽  
Samia Achour
Keyword(s):  
Activated Carbon ◽  
Natural Waters ◽  
Granular Activated Carbon ◽  
Second Order ◽  
Phosphate Adsorption ◽  
Particle Diffusion ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

The objective of this work is to study the phosphate adsorption from natural waters by using a granular activated carbon (GAC). Experiments were carried out with synthetic solutions of phosphate prepared using groundwater (mineralized drinking water). Batch tests were carried out in order to study different operating parameters such as the effect of contact time, pH, initial phosphate concentration and adsorbent dosage. In addition, the adsorption kinetic data were simulated using the pseudo first order, the pseudo second-order and the intra-particle diffusion model. The sorption equilibrium was analyzed by Langmuir, Freundlich and Dubinin–Radushkevich isotherms model. Results show that the phosphate adsorption was reversible and the quantity adsorbed reached its maximum value (2.82 mg/g) after 30 min. It was also found that phosphate uptake was affected by variation of pH, initial concentration of phosphate and granular activated carbon dosage. The adsorption improved with increase in pH values, initial concentration and adsorbent dosage. The results of kinetic studies revealed that pseudo-second-order model adequately described the adsorption phosphate on GAC and the intra-particle diffusion involved in the adsorption mechanism. Also, isotherm study showed that Langmuir isotherm best fit the data and the adsorption was a physical type.

Kinetic Study of Arsenic(V) Absorption with Al2O3 Functionalized SBA-15

2013 ◽  
Vol 726-731 ◽  
pp. 2191-2197 ◽  
Author(s):  
Su Yun He ◽  
Cai Yun Han ◽  
Su Fang He ◽  
Hua Wang ◽  
Chun Xia Liu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Second Order ◽  
Particle Diffusion ◽  
Order Model ◽  
Surface Absorption ◽  
Arsenic Uptake ◽  
First Order ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Pseudo First Order

This research presented the kinetic performance of arsenic absorption by mesostructure SBA-15 functionalized with Al2O3. The SBA-15 was previously synthesised and subsequently functionalized via impregnation of alumina oxides. The absorption of arsenic(V) was studied as a function of absorbent dosage and contact time. The experimental data were fitted to kinetic pseudo-first order, pseudo-second order and the intra-particle diffusion model. The pseudo-second order model presented the best correlation with the experimental data. Both surface absorption and intra-particle diffusion were acting during arsenic uptake, except for absorbent dosage of 0.1g, which was mainly controlled by the intra-particle diffusion.

scholarly journals Investigation of carbon monoxide gas adsorption on the Al2O3/Pd(NO3)2/zeolite composite film

2019 ◽  
Vol 14 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Nastaran Mozaffari ◽  
Alireza Haji Seyed Mirzahosseini ◽  
Amir Hossein Sari ◽  
Leila Fekri Aval
Keyword(s):  
Gas Adsorption ◽  
Co Adsorption ◽  
Second Order ◽  
Particle Diffusion ◽  
X Ray ◽  
Gas Concentration ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Zeolite Composite ◽  
Co Gas

AbstractIn this study, Al2O3/Pd(NO3)2/zeolite composite films have been fabricated by roll coating method and characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy. The gas adsorption was tested in an experimental setup by a continuous gas analyzer KIMO KIGAZ 210 at constant temperature and pressure (32 °C and 1.5 bar) and as a function of reaction time (s). The inlet CO gas concentration was 150 mg L−1, and the saturation level of CO gas concentration was 5 mg L−1. The maximum adsorption capacity (qmax) and maximum adsorption efficiency (%) were calculated as 111.16 mg g−1 and 97%, respectively. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were investigated to kinetic study of CO adsorption on Al2O3/Pd(NO3)2/zeolite adsorbents. Results indicated that CO adsorption follows the pseudo-second-order model well according to regression coefficient value (R2 = 0.98), and the value of pseudo-second-order rate constant of adsorption was obtained as 2 × 10−5 g mg−1 s−1. According to the intra-particle diffusion model, adsorption is affected by only one process. So, adsorption of CO by Al2O3/Pd(NO3)2/zeolite adsorbent indicated an effective adsorption by obtained results.

scholarly journals Equilibrium and kinetic studies of Pb(II), Cd(II) and Zn(II) sorption by Lagenaria vulgaris shell

2012 ◽  
Vol 18 (4-1) ◽  
pp. 563-576 ◽  
Author(s):  
Dragana-Linda Mitic-Stojanovic ◽  
Danijela Bojic ◽  
Jelena Mitrovic ◽  
Tatjana Andjelkovic ◽  
Miljana Radovic ◽  
...  
Keyword(s):  
Metal Ions ◽  
Sorption Capacity ◽  
Second Order ◽  
Isotherm Models ◽  
Particle Diffusion ◽  
Order Kinetic ◽  
Sorption Data ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Lagenaria Vulgaris

The sorption of lead, cadmium and zinc ions from aqueous solution by Lagenaria vulgaris shell biosorbent (LVB) in batch system was investigated. The effect of relevant parameters such as contact time, biosorbent dosage and initial metal ions concentration was evaluated. The Pb(II), Cd(II) and Zn(II) sorption equilibrium (when 98% of initial metal ions were sorbed) was attained within 15, 20 and 25 min, respectively. The pseudo first, pseudo-second order, Chrastil?s and intra-particle diffusion models were used to describe the kinetic data. The experimental data fitted the pseudo-second order kinetic model and intra-particle diffusion model. Removal efficiency of lead(II), cadmium(II) and zinc(II) ions rapidly increased with increasing biosorbent dose from 0.5 to 8.0 g dm-3. Optimal biosorbent dose was set to 4.0 g dm-3. An increase in the initial metal concentration increases the sorption capacity. The sorption data of investigated metal ions are fitted to Langmuir, Freundlich and Temkin isotherm models. Langmuir model best fitted the equilibrium data (r2 > 0.99). Maximal sorption capacities of LVB for Pb(II), Cd(II) and Zn(II) at 25.0?0.5?C were 0.130, 0.103 and 0.098 mM g-1, respectively. The desorption experiments showed that the LVB could be reused for six cycles with a minimum loss of the initial sorption capacity.

scholarly journals Novel Adsorbent for Industrial Wastewater Treatment Applications

2019 ◽  
Vol 9 (1) ◽  
pp. 1219-1225
Keyword(s):  
Methylene Blue ◽  
Second Order ◽  
Thymol Blue ◽  
Batch Adsorption ◽  
Particle Diffusion ◽  
Maximum Adsorption Capacity ◽  
Basic Solution ◽  
Order Kinetic ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order

In this study, the hydroxyapatite powder is investigated for both of methylene blue and thymol blue in aqueous solution. The physical and chemical properties of the adsorbent were evaluated systematically using the different techniques including Microsoft Excel programming, linear regression model and also the coefficient of determination. Batch adsorption experiments were conducted to determine the effect of contact time, solution pH, initial dye concentrations, and also the adsorbent dosage on adsorption. The adsorption kinetic parameters confirmed the better fitting of pseudo-second order kinetic model for both of methylene blue and thymol blue. The isotherm data of methylene blue and thymol blue could be well described by the Freundlich isotherm model which means the adsorption is multilayer adsorption with non-uniform distribution of adsorption heat and affinities over the heterogeneous surface. The maximum adsorption capacity (KF) of methylene blue and thymol blue is found to be 0.2736 (L/mg) and 11.18407 (L/mg) respectively. The high specific surface area and the porous structure with some acidic functional groups on the surface were obviously responsible for high dyes adsorption onto hydroxyapatite (HA). Adsorption kinetics data were modeled with the application of Pseudo first order, Pseudo second order and Intraparticle diffusion models. The results revealed that the Pseudo second order model was the best fitting model. Which means that, the adsorption mechanism followed two stages in which the first one was fast and the other was slower step. Which means the adsorption of dye molecules was limited by intra particle diffusion and film diffusion, as well as, the adsorption rate in both of adsorption system are depends only on the slower step.The Boyd plot exposed that the intra-particle diffusion was the rate controlling step of the adsorption process of both of methylene blue and thymol blue molecules by HA powder. However, the adsorption of methylene blue molecules (basic solution) using of HA as adsorbent particles is found to be extremely preferable than thymol blue molecules.

scholarly journals Application of activated bentonite for the removal of direct and reactive dye from aqueous solutions

2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic
Keyword(s):  
Aqueous Solutions ◽  
Dye Adsorption ◽  
Bentonite Clay ◽  
Reactive Dye ◽  
Second Order ◽  
Intra Particle Diffusion ◽  
Naoh Solution ◽  
Activated Bentonite ◽  
Endothermic Process ◽  
Pseudo Second Order

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.

scholarly journals Removal Effect of Atrazine in Co-Solution with Bisphenol A or Humic Acid by Different Activated Carbons

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2558 ◽  
Author(s):  
Zhansheng Wu ◽  
Xinhui Wei ◽  
Yongtao Xue ◽  
Xiufang He ◽  
Xia Yang
Keyword(s):  
Humic Acid ◽  
Bisphenol A ◽  
Adsorption Kinetics ◽  
Competitive Adsorption ◽  
Activated Carbons ◽  
Second Order ◽  
Adsorption Behavior ◽  
Single Solution ◽  
Pseudo Second Order ◽  
Kinetics Of

Activated carbons (ACs) based on apricot shells (AS), wood (W), and walnut shells (WS) were applied to adsorb atrazine in co-solutions. To study the effect of Bisphenol A (BPA) on the adsorption behavior of atrazine, the adsorption performance of ACs for BPA in single solution was studied. The results demonstrated that the adsorption kinetics of BPA fitted the pseudo-second-order model, the adsorption isotherms of BPA followed the Langmuir model. Meanwhile, the adsorption kinetics of atrazine fitted the pseudo-second-order kinetics model and the isotherm was consistent with the Freundlich model both in single solution and co-solution. In addition, competitive adsorption was observed when atrazine coexisted with BPA or humic acid. For the adsorption capacity, the adsorption amount of ASAC, WAC, and WSAC for atrazine obviously decreased by 18.0%, 30.0%, and 30.3% in the presence of BPA, respectively, which was due to the π−π interactions, hydrophobic interactions, and H-bonds, resulting in the competitive adsorption between atrazine and BPA. This study contributes to the further understanding of the adsorption behavior for atrazine in co-solution.

Biopolymeric Adsorbent for the Removal of Methylene Blue: Characterizations, Equilibrium Isotherms and Kinetic Studies

2015 ◽  
Vol 1125 ◽  
pp. 281-285
Author(s):  
Siti Aishah Muhmed ◽  
Mohd Ghazali Mohd Nawawi
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Correlation Coefficient ◽  
Kinetic Studies ◽  
Second Order ◽  
Equilibrium Isotherms ◽  
Chi Square ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.

Sign in / Sign up

Export Citation Format

Share Document