scholarly journals Synthesis and application of CeO2/sawdust nanocomposite for removal of As (III) ions from aqueous solutions using a fixed bed column system

2016 ◽  
Vol 19 (1) ◽  
pp. 7-16 ◽  

<p>In this study, nanocomposite of ceria sawdust (CeO<sub>2</sub>/SD) synthesized by precipitation method was utilized for removal of As (III) ions from aqueous solutions. Study of the process was done in column system. Characterization of the nano sized adsorbent particles was carried out using XRD and SEM techniques. The effects of important parameters, such as the value of initial pH, the flow rate, the influent concentration of arsenic and bed depth were studied in the column system. The Thomas model was applied for treatment of the adsorption data at different flow rate, influent concentration and bed depth. The bed-depth/service time analysis (BDST) model was also applied at different bed depth to predict the breakthrough curves. The two models were found suitable for describing the bio sorption process of the dynamic behavior of the CeO<sub>2</sub>/SD adsorbent in column investigation. Based on Thomas model, the equilibrium adsorption reached 8.28 mg g<sup>−</sup><sup>1</sup> when a As(III) polluted solution with influent concentration of As 10 mg l<sup>-1 </sup>passed through the column with a flow rate of 2 ml min<sup>−</sup><sup>1</sup>. All the results suggested the presented nanocomposite as an efficient and cost effective adsorbent for removal of As (III) ions from aqueous solutions.</p>

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.


2017 ◽  
Vol 19 (3) ◽  
pp. 412-422 ◽  

This study describes the removal of Cr (VI) ions from aqueous solutions using silver oxide/sawdust nanocomposite (Ag2O/SD NC) that was prepared using the chemical precipitation method. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques were used for characterization of Ag2O/SD NC. The effect of various parameters such as feed solution pH (2, 6, and 10), influent concentration of Chromium (VI) (25-100 mg/L), flow rate (1-5 mL/min) and bed depth (4-12 cm) on breakthrough curves (BTC) were investigated. Three well-known column adsorption kinetics models including Thomas, Adams-Bohart and Bed Depth Service Time (BDST) models were applied to fitting the column experimental data. Based on Thomas model, the equilibrium adsorption reached 13.41 mg/g when a Cr (VI) polluted solution with influent concentration of 25 mg/L Cr (VI) passed through the column with a flow rate of 2 mL/min. Desorption studies reveal that recovery of uploaded Cr (VI) from the Ag2O/SD NC adsorbent or exhausted column regeneration can readily be achieved using a dilute solution of NaOH (0.01 M) as eluent. This study indicated that the Ag2O/SD NC can be used as an effective, efficient and environmentally friendly adsorbent for the removal of Cr (VI) ions from water resources.


2011 ◽  
Vol 287-290 ◽  
pp. 1620-1625
Author(s):  
Yan Wu ◽  
Zai Fang Deng ◽  
Yang Tao ◽  
Xue Gang Luo

Fixed-bed column studies for the removal of Ag(Ⅰ) and Cr(Ⅲ) from individual aqueous solutions using puffed rice husk were investigated in this work. The experiments were conducted to study the effect of important column parameters such as bed height, feed flow rate and feed initial concentration of solution. It was found that increasing bed depth yielded longer service time while increase in influent concentration and flow rate resulted in faster breakthrough. Bed Depth Service Time (BDST) model was applied to analyze the experimental data and the model parameters were evaluated. Good agreement of the experimental breakthrough curves with the model predictions was observed.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4725
Author(s):  
Camilla Costa ◽  
Matteo Cornacchia ◽  
Marcello Pagliero ◽  
Bruno Fabiano ◽  
Marco Vocciante ◽  
...  

An experimental study of hydrogen sulfide adsorption on a fixed bed for biogas purification is proposed. The adsorbent investigated was powdered hematite, synthesized by a wet-chemical precipitation method and further activated with copper (II) oxide, used both as produced and after pelletization with polyvinyl alcohol as a binder. The pelletization procedure aims at optimizing the mechanical properties of the pellet without reducing the specific surface area. The active substrate has been characterized in its chemical composition and physical properties by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), thermogravimetric analysis (TGA) and N2 physisorption/desorption for the determination of surface area. Both powders and pellets have been tested as sorbents for biogas purification in a fixed bed of a steady-state adsorption column and the relevant breakthrough curves were determined for different operating conditions. The performance was critically analyzed and compared with that typical of other commercial sorbents based on zinc oxide or relying upon specific compounds supported on a chemically inert matrix (SulfaTreat®). The technique proposed may represent a cost-effective and sustainable alternative to commercial sorbents in conventional desulphurization processes.


2014 ◽  
Vol 884-885 ◽  
pp. 16-20
Author(s):  
Hai Ning Liu ◽  
Hui Fang Zhang ◽  
Can Gao ◽  
Xiu Shen Ye ◽  
Zhi Jian Wu

A column sorption study was carried out by using four resins (D113, D001, LS-1000, LS-5000) for the adsorption of alkaline-earth metal ions from aqueous solutions. The breakthrough curve was obtained as a function of feed flow rate, and the total and breakthrough capacity values of the resins were calculated. Four kinetic models: Adams-Bohart, Wolborska and Thomas models were applied to experimental data to predict the breakthrough curves of Na-form resins and to determine the characteristic parameters of the column useful for process design. All models were found suitable for describing the whole or a definite part of the dynamic behavior of the column with respect to flow rate and inlet ion concentration. The results obtained would be helpful for the understanding of the competitive adsorption processes and the recovery or removal of one or more alkaline-earth metal ions from aqueous solutions.


2019 ◽  
Vol 17 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Mohammad Javad Amiri ◽  
Maryam Khozaei ◽  
Antonio Gil

Abstract The Thomas equation is a popular model that has been widely used to predict breakthrough curves (BTCs) when describing the dynamic adsorption of different pollutants in a fixed-bed column system. However, BTCs commonly exhibit unsymmetrical patterns that cannot be predicted using empirical equations such as the Thomas model. Fortunately, adaptive neural-based fuzzy inference systems (ANFISs) can be used to model complex patterns found in adsorption processes in a fixed-bed column system. Consequently, a new hybrid model merging Thomas and an ANFIS was introduced to estimate the performance of BTCs, which were obtained for Cd(II) ion adsorption on ostrich bone ash-supported nanoscale zero-valent iron (nZVI). The results obtained showed that the fair performance of the Thomas model (NRMSE = 27.6% and Ef = 64.6%) improved to excellent (NRMSE = 3.8% and Ef = 93.8%) due to the unique strength of ANFISs in nonlinear modeling. The sensitivity analysis indicated that the initial solution pH was a more significant input variable influencing the hybrid model than the other operational factors. This approach proves the potential of this hybrid method to predict BTCs for the dynamic adsorption of Cd(II) ions by ostrich bone ash-supported nZVI particles. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.


2019 ◽  
Vol 120 ◽  
pp. 03003
Author(s):  
Huang-Mu Lo ◽  
Kae-Long Lin ◽  
Min-Hsin Liu ◽  
Hsung-Ying Chiu ◽  
Fang-Cheng Lo

Heavy metals from the electroplating wastewater might cause environmental pollution if not well treated. Generally, carbon adsorption might be used for the final step for further trace metals removal. This study investigated the heavy metal Cu adsorption in the fixed bed column with 1, 10 and 100 mg/L influent concentration. Results showed that KAB decreased as influent Cu concentration increased from 1 to 100 mg/L while N0 increased as influent concentration increased from 1 to 100 mg/L as can be found in Adams-Bohart model. R2 was found between 0.8579 and 0.9182. In Thomas model. KTH and q0 showed the similar trend as KAB and N0 in the Adams-Bohart model. KTH decreased as influent Cu concentration increased from 1 to 100 mg/L. q0 increased as influent Cu concentration increased from 1 to 100 mg/L. R2 of regression model was found between 0.9065 and 0.9836. In Yoon-Nelson model. KYN increased as influent Cu concentration increased from 1 to 100 mg/L while τ decreased as influent Cu concentration increased from 1 to 100 mg/L. Results showed that the three models of Adams-Bohart model, Thmoas model and The Yoon-Nelson model were suitable for the description of Cu adsorption by activated carbon.


2020 ◽  
Vol 990 ◽  
pp. 177-182
Author(s):  
Toungrat Janpattanapong ◽  
Kowit Piyamongkala ◽  
Von Louie R. Manguiam

The modified sugarcane bagasse with aluminum sulfate was used as an adsorbent for the removal of soluble oil wastewater. The effects of the flow rate, 5 and 10 cm3/min and the number of columns used were thoroughly investigated in a continuous up-flow adsorption process. At the flow rate of 5 cm3/min respected to the 2nd column, the highest breakthrough point to adsorb soluble oil wastewater was at 6 hrs. The results confirmed that the modified sugarcane bagasse can be used as an adsorbent for fixed-bed continuous adsorption of soluble oil wastewater from steel pipe factory. The breakthrough curves were predicted by Yoon-Nelson model. This model may be fitted to predict the overall breakthrough curve using the experimental data gathered. In addition, the significant uptake of the soluble oil wastewater was demonstrated by the changes in the heat of combustion of the modified sugarcane bagasse before and after the adsorption process.


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.


Clay Minerals ◽  
2015 ◽  
Vol 50 (1) ◽  
pp. 91-101 ◽  
Author(s):  
I. Nuić ◽  
M. Trgo ◽  
J. Perić ◽  
N. Vukojević Medvidović

AbstractThe removal of lead and zinc from a binary solution by fixed bed depths (40, 80 and 120 mm) of a natural zeolite was examined at a flow rate of 1 mL/min. The results obtained were fitted to the Bed Depth Service Time (BDST) model and the parameters of the model (q and k) were used to design a column system for flow rates of 2 and 3 mL/min at a bed depth of 80 mm. The experimental results were in excellent agreement with those predicted and experimental breakthrough curves for the binary systems were obtained. This approach facilitates the design of effective binary column processes without additional experimentation. Two major design parameters, the Empty Bed Contact Time (EBCT) and the zeolite usage rate, were calculated. The highest EBCT value of 13.56 min represents the optimal conditions for the binary (Pb+Zn) solution.


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