scholarly journals Adsorption of Azo Dye Methyl Orange from Aqueous Solutions Using Alkali-Activated Polypyrrole-Based Graphene Oxide

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3685 ◽  
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Abdel-Basit Al-Odayni ◽  
Waseem Sharaf Saeed ◽  
Mohammed S. Almutairi ◽  
Fahad A. Alharthi ◽  
...  

The adsorption of methyl orange (MO) from aqueous solutions onto a KOH-activated polypyrrole-based adsorbent (PACK) was investigated using batch and fixed-bed column techniques. The structural, thermal, and morphological properties of the PACK, analyzed by various methods, support its applicability as an adsorbent. An adsorption kinetic study revealed a preferably pseudo-second-order (R2 = 0.9996) and rate-limiting step controlled by both film and intra-particle diffusions. The thermodynamic adsorption tests resulted in negative ΔG°, ΔH°, and ΔS° values, which decreased as the temperature and concentration increased, indicating the spontaneous and exothermic adsorption over 25–45 °C. The adsorption isotherms fit the experimental data in the order of Langmuir ≈ Freundlich > Temkin, with evidence of adsorption operating well via the monolayer physical adsorption process, and maximum monolayer adsorption ranging from 520.8 to 497.5 mg/g. The breakthrough curve of the fixed-bed column experiment was modeled using the Thomas, Yoon–Nelson, and Hill models, resulting in an equilibrium capacity of 57.21 mg/g. A 73% MO recovery was achieved, indicating the possibility of column regeneration. Compared to other adsorbents reported, PACK had comparable or even superior capacity toward MO. For cost-effectiveness, similar nitrogen-containing polymeric wastes could be exploited to obtain such excellent materials for various applications.

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.


2020 ◽  
Vol 9 (1) ◽  
pp. 770-782
Author(s):  
Tianpeng Li ◽  
Jing Fan ◽  
Tingting Sun

AbstractA novel porous ceramsite was made of municipal sludge, coal fly ash, and river sediment by sintering process, and the performance of batch and fixed-bed column systems containing this material in the removal of acid red G (ARG) dye from aqueous solutions was assessed in this study. The results of orthogonal test showed that sintering temperature was the most important determinant in the preparation of porous ceramsite, and it possesses developed pore structure and high specific surface area. Batch experiment results indicated that the adsorption process of ARG dye toward porous ceramsite was a spontaneous exothermic reaction, which could be better described with Freundlich–Langmuir isotherm model (R2 > 0.992) and basically followed the pseudo-first-order kinetic equation (R2 > 0.993). Column experiment results showed that when the porous ceramsite was used as packing material, its adsorption capacity was roughly improved by 3.5 times compared with that in batch system, and the breakthrough behavior was simulated well with Yoon–Nelson model, with R2 > 0.954. This study suggested that the novelty man-made porous ceramsite obtained from solid wastes might be processed as a certain cost-effective treatment material fit for the dye removal in aqueous solutions.


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.


2019 ◽  
Vol 36 (9) ◽  
pp. 1162-1169 ◽  
Author(s):  
Juanjuan Qu ◽  
Yue Li ◽  
Tingting Zang ◽  
Yu Jin ◽  
Xuesheng Liu ◽  
...  

2013 ◽  
Vol 49 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Antonio David Dorado ◽  
Xavier Gamisans ◽  
Cesar Valderrama ◽  
Montse Solé ◽  
Conxita Lao

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bo Bai ◽  
Xiaohui Xu ◽  
Changchuan Li ◽  
Jianyu Xing ◽  
Honglun Wang ◽  
...  

The adsorptive removal of antibiotics from aqueous solutions is recognized as the most suitable approach due to its easy operation, low cost, nontoxic properties, and high efficiency. However, the conventional regeneration of saturated adsorbents is an expensive and time-consuming process in practical wastewater treatment. Herein, a scalable adsorbent of magnetic Fe3O4@chitosan carbon microbeads (MCM) was successfully prepared by embedding Fe3O4 nanoparticles into chitosan hydrogel via an alkali gelation-thermal cracking process. The application of MCM composites for the adsorptive removal of doxycycline (DC) was evaluated using a fixed-bed column. The results showed that pH, initial concentration, flow rate, and bed depth are found to be important factors to control the adsorption capacity of DC. The Thomas and Yoon-Nelson models showed a good agreement with the experimental data and could be applied for the prediction of the fixed-bed column properties and breakthrough curves. More importantly, the saturated fixed bed can be easily recycled by H2O2 which shows excellent reusability for the removal of doxycycline. Thus, the combination of the adsorption advantage of chitosan carbon with catalytic properties of magnetic Fe3O4 nanoparticles might provide a new tool for addressing water treatment challenges.


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