Applications and limits of theoretical adsorption models for predicting the adsorption properties of adsorbents

2015 ◽  
Vol 72 (8) ◽  
pp. 1364-1374 ◽  
Author(s):  
Hyun Ju Park ◽  
Duc Canh Nguyen ◽  
Choon-Ki Na ◽  
Chung-il Kim

The objective of this study is to evaluate the applicability of adsorption models for predicting the properties of adsorbents. The kinetics of the adsorption of NO3− ions on a PP-g-AA-Am non-woven fabric have been investigated under equilibrium conditions in both batch and fixed bed column processes. The adsorption equilibrium experiments in the batch process were carried out under different adsorbate concentration and adsorbent dosage conditions and the results were analyzed using adsorption isotherm models, energy models, and kinetic models. The results of the analysis indicate that the adsorption occurring at a fixed adsorbate concentration with a varying adsorbent dosage occur more easily compared to those under a fixed adsorbent dosage with a varying adsorbate concentration. In the second part of the study, the experimental data obtained using fixed bed columns were fit to Bed Depth Service Time, Bohart–Adams, Clark, and Wolborska models, to predict the breakthrough curves and determine the column kinetic parameters. The adsorption properties of the NO3− ions on the PP-g-AA-Am non-woven fabric were differently described by different models for both the batch and fixed bed column process. Therefore, it appears reasonable to assume that the adsorption properties were dominated by multiple mechanisms, depending on the experimental conditions.

2019 ◽  
Vol 19 (2) ◽  
pp. 486 ◽  
Author(s):  
Nguyen Thi Thuong ◽  
Nguyen Thi Tuyet Nhi ◽  
Vo Thi Cam Nhung ◽  
Hoang Ngoc Bich ◽  
Bui Thi Phuong Quynh ◽  
...  

A number of harmful effects on the ecosystem, the life of humankind, and living species caused by dye-contaminated wastewater have urged the development for an efficient and cost-efficient treatment method for colored effluents. The cellulose-based adsorbents have been considered as a facile and efficient approach to remove hazardous pollutants because of the abundance of inexpensive agricultural wastes in Viet Nam. This study aims to investigate the elimination of methylene blue (MB) and crystal violet (VL) from wastewater using a fixed-bed column of pre-treated durian peel. Examined variables in the process are bed depths (2–6 cm), flow rate (5–20 mL/min), and influent dye concentrations (200–600 mg/L). The highest adsorption amount of pre-treated DP was 235.80 mg/g and 527.64 mg/g, respectively, on a 600 mg/L of methylene blue and crystal violet achieved within a bed height of 4 cm and a flow rate of 10 mL/min. Accordingly, the breakthrough curves were constructed and modeled using the relevant theoretical models under the effects of different experimental conditions. Pre-treated durian peel was found to exhibit high adsorption capacity for cationic dye in an initial concentration of 200–600 mg/L with complete removal being obtained.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shazia Perveen ◽  
Raziya Nadeem ◽  
Shaukat Ali ◽  
Yasir Jamil

Abstract Biochar caged zirconium ferrite (BC-ZrFe2O5) nanocomposites were fabricated and their adsorption capacity for Reactive Blue 19 (RB19) dye was evaluated in a fixed-bed column and batch sorption mode. The adsorption of dye onto BC-ZrFe2O5 NCs followed pseudo-second-order kinetics (R 2 = 0.998) and among isotherms, the experimental data was best fitted to Sips model as compared to Freundlich and Langmuir isotherms models. The influence of flow-rate (3–5 mL min−1), inlet RB19 dye concentration (20–100 mg L−1) and quantity of BC-ZrFe2O5 NCs (0.5–1.5 g) on fixed-bed sorption was elucidated by Box-Behnken experimental design. The saturation times (C t /C o  = 0.95) and breakthrough (C t /C o  = 0.05) were higher at lower flow-rates and higher dose of BC-ZrFe2O5 NCs. The saturation times decreased, but breakthrough was increased with the initial RB19 dye concentration. The treated volume was higher at low sorbent dose and influent concentration. Fractional bed utilization (FBU) increased with RB19 dye concentration and flow rates at low dose of BC-ZrFe2O5 NCs. Yan model was fitted best to breakthrough curves data as compared to Bohart-Adams and Thomas models. Results revealed that BC-ZrFe2O5 nanocomposite has promising adsorption efficiency and could be used for the adsorption of dyes from textile effluents.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 510
Author(s):  
Majeda Khraisheh ◽  
Fares. Almomani ◽  
Gavin Walker

The separation of C3H4/C3H6 is one of the most energy intensive and challenging operations, requiring up to 100 theoretical stages, in traditional cryogenic distillation. In this investigation, the potential application of two MOFs (SIFSIX-3-Ni and NbOFFIVE-1-Ni) was tested by studying the adsorption–desorption behaviors at a range of operational temperatures (300–360 K) and pressures (1–100 kPa). Dynamic adsorption breakthrough tests were conducted and the stability and regeneration ability of the MOFs were established after eight consecutive cycles. In order to establish the engineering key parameters, the experimental data were fitted to four isotherm models (Langmuir, Freundlich, Sips and Toth) in addition to the estimation of the thermodynamic properties such as the isosteric heats of adsorption. The selectivity of the separation was tested by applying ideal adsorbed solution theory (IAST). The results revealed that SIFSIX-3-Ni is an effective adsorbent for the separation of 10/90 v/v C3H4/C3H6 under the range of experimental conditions used in this study. The maximum adsorption reported for the same combination was 3.2 mmolg−1. Breakthrough curves confirmed the suitability of this material for the separation with a 10-min gab before the lighter C3H4 is eluted from the column. The separated C3H6 was obtained with a 99.98% purity.


2012 ◽  
Vol 518-523 ◽  
pp. 3115-3119
Author(s):  
Yan Qiang Li ◽  
Xiao Feng Ren ◽  
Shao Hua Chen ◽  
Xiu Rong Zhao ◽  
Run Ping Han

The effect of bed depth on adsorption ability of natural zeolite to removal methylene blue (MB) from aqueous solution in the fixed-bed column was studied. The results showed that the increase in column height favored the MB removal form solution. The equilibrium uptake of MB onto unit mass zeolite increased with the bed depth growth. The experimental data were fitted to Yan model using linear and nonlinear regression analysis, respectively. The experimental points and the predicted curves using the Yan model were compared and the error analysis was performed. The results indicated that Yan model were good to predict the breakthrough curves and both two methods can be used to obtain the parameters of Yan model and to predict the breakthrough curves.


2021 ◽  
Vol 891 ◽  
pp. 31-36
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Camille Margaret S. Alvarillo ◽  
Joshua L. Chua ◽  
Ysabel Marie C. Gonzales ◽  
Jem Valerie D. Perez

Continuous fixed-bed column studies were performed using nanocomposite beads made up of chitosan, polyethyleneimine, and graphene oxide as adsorbents for the removal of methyl orange (MO) in water. The effects of different operating parameters such as initial MO concentration (5, 10, and 15 ppm), bed height (10, 17.5, and 25 cm), and flow rate (27, 43, and 58 mL/min) were investigated using an upward-flow fixed-bed column set-up. The breakthrough curves generated were fitted with Adams-Bohart, Thomas, Yoon-Nelson, and Yan et al. models. The results showed that Yan et al. model agreed best with the breakthrough curves having an R2 as high as 0.9917. Lastly, design parameters for a large-scale adsorption column were determined via scale-up approach using the parameters obtained from column runs.


2018 ◽  
Vol 8 (11) ◽  
pp. 2221 ◽  
Author(s):  
Olga Długosz ◽  
Marcin Banach

Vermiculite has been used for the removal of Cu 2 + and Ag + from aqueous solutions in a fixed-bed column system. The effects of initial silver and copper ion concentrations, flow rate, and bed height of the adsorbent in a fixed-bed column system were investigated. Statistical analysis confirmed that breakthrough curves depended on all three factors. The highest inlet metal cation concentration (5000 mg/dm3), the lowest bed height (3 cm) and the lowest flow rate (2 and 3 cm3/min for Ag + and Cu 2 + , respectively) were optimal for the adsorption process. The maximum total percentage of metal ions removed was 60.4% and 68.7% for Ag+ and Cu2+, respectively. Adsorption data were fitted with four fixed-bed adsorption models, namely Clark, Bohart–Adams, Yoon–Nelson and Thomas models, to predict breakthrough curves and to determine the characteristic column parameters. The adsorbent was characterized by SEM, FTIR, EDS and BET techniques. The results showed that vermiculite could be applied as a cost-effective sorbent for the removal of Cu 2 + and Ag + from wastewater in a continuous process.


2011 ◽  
Vol 64 (3) ◽  
pp. 654-660 ◽  
Author(s):  
Xiuli Han ◽  
Wei Wang ◽  
Xiaojian Ma

The adsorption potential of lotus leaf to remove methylene blue (MB) from aqueous solution was investigated in batch and fixed-bed column experiments. Langmuir, Freundlich, Temkin and Koble–Corrigan isotherm models were employed to discuss the adsorption behavior. The results of analysis indicated that the equilibrium data were perfectly represented by Temkin isotherm and the Langmuir saturation adsorption capacity of lotus leaf was found to be 239.6 mg g−1 at 303 K. In fixed-bed column experiments, the effects of flow rate, influent concentration and bed height on the breakthrough characteristics of adsorption were discussed. The Thomas and the bed-depth/service time (BDST) models were applied to the column experimental data to determine the characteristic parameters of the column adsorption. The two models were found to be suitable to describe the dynamic behavior of MB adsorbed onto the lotus leaf powder column.


2011 ◽  
Vol 46 (6) ◽  
pp. 1270-1277 ◽  
Author(s):  
Carlos André V. Burkert ◽  
Geraldo N.O. Barbosa ◽  
Marcio A. Mazutti ◽  
Francisco Maugeri

2019 ◽  
Vol 122 ◽  
pp. 01002 ◽  
Author(s):  
Ibrahim Yildiz ◽  
Banu Sizirici

Iron oxide-coated gravel as an adsorbent was employed in continuous fixed bed column study to remove Fe(II), Ni(II), and Zn(II) simultaneously in synthetic leachate samples. Experimental and modeled adsorption capacities derived from the breakthrough curves showed the adsorption capacity order of Zn(II)>Fe(II)> Ni(II). Iron oxide-coated gravel column removed 58.24% of Zn(II), 47.71% of Fe(II), and 39.45% of Ni(II). Desorption process was studied in order to test the regeneration capability of iron oxidecoated gravel. It was seen that 99.64 % of Ni(II), 99.54% of Fe(II) and 6.75% of Zn (II) were recovered through the first cycle of adsorption/desorption. In the second cycle, the recovery rates dropped to 81.4% for Ni(II), 80% for Fe(II) and 4% for Zn(II). Based on these results, iron oxide coated gravel has potential to remove mixed metal ions simultaneously in aqueous solutions.


Sign in / Sign up

Export Citation Format

Share Document