scholarly journals Adsorption of Hg(II) and Pb(II) ions by nanoscale zero valent iron supported on ostrich bone ash in a fixed-bed column system

2017 ◽  
Vol 76 (3) ◽  
pp. 671-682 ◽  
Author(s):  
Mohammad Javad Amiri ◽  
Jahangir Abedi-koupai ◽  
Saeid Eslamian
Keyword(s):  
Metal Ions ◽  
Ph Value ◽  
Fixed Bed ◽  
Zerovalent Iron ◽  
Fixed Bed Column ◽  
Flow Rates ◽  
Nanoscale Zerovalent Iron ◽  
Column System ◽  
Bed Height ◽  
Bone Ash

In this research, ostrich bone ash (OBA) was modified with nanoscale zerovalent iron (nZVI) particles and applied as a novel composite adsorbent (OBA/nZVI) for dynamic adsorption/reduction of Hg(II) and Pb(II) ions in a fixed-bed column system. Entrapment of nZVI in OBA beads barricades the particles from oxidation and aggregation. The dynamic behavior of metal ions removal by OBA/nZVI was assessed as a function of inlet flow rates, bed height, initial pollutants concentration and pH. The synthesized OBA/nZVI composite was characterized by several physicochemical techniques. Increase in pH and bed height and decrease in flow rates and initial metal concentration resulted in delay of breakthrough time. OBA breakthrough profile is sharper than the OBA/nZVI breakthrough curve for both metal ions and the breakthrough times increase in the order OBA/nZVI-Hg(II) > OBA/nZVI-Pb(II) > OBA-Pb(II) > OBA-Hg(II). Based on the experiment results, redox reaction is expected to occur to a certain extent, as the standard reduction potentials of Hg(II) and Pb(II) are more than that of Fe(II). From a practical point of view, the OBA/nZVI could be applied as a material to remove Hg(II) and Pb(II) ions from natural surface and ground water with a pH value of 5–9.

scholarly journals Sorption of Ag+ and Cu2+ by Vermiculite in a Fixed-Bed Column: Design, Process Optimization and Dynamics Investigations

2018 ◽  
Vol 8 (11) ◽  
pp. 2221 ◽  
Author(s):  
Olga Długosz ◽  
Marcin Banach
Keyword(s):  
Flow Rate ◽  
Continuous Process ◽  
Fixed Bed ◽  
Copper Ion ◽  
Cost Effective ◽  
Breakthrough Curves ◽  
Fixed Bed Column ◽  
Column System ◽  
Total Percentage ◽  
Bed Height

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.

scholarly journals Modification of the Thomas model for predicting unsymmetrical breakthrough curves using an adaptive neural-based fuzzy inference system

2019 ◽  
Vol 17 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Mohammad Javad Amiri ◽  
Maryam Khozaei ◽  
Antonio Gil
Keyword(s):  
Hybrid Model ◽  
Fuzzy Inference ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Dynamic Adsorption ◽  
Thomas Model ◽  
Fixed Bed Column ◽  
Column System ◽  
Bone Ash ◽  
Model Complex

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.

Modeling of Fixed-Bed Column System of Hg(II) Ions on Ostrich Bone Ash/nZVI Composite by Artificial Neural Network

2017 ◽  
Vol 143 (9) ◽  
pp. 04017061 ◽  
Author(s):  
Mohammad Javad Amiri ◽  
Jahangir Abedi-koupai ◽  
Seyed Mohammad Jafar Jalali ◽  
Sayed Farhad Mousavi
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Fixed Bed ◽  
Fixed Bed Column ◽  
Column System ◽  
Bone Ash ◽  
Artificial Neural

Biochar caged zirconium ferrite nanocomposites for the adsorptive removal of Reactive Blue 19 dye in a batch and column reactors and conditions optimizaton

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shazia Perveen ◽  
Raziya Nadeem ◽  
Shaukat Ali ◽  
Yasir Jamil
Keyword(s):  
Experimental Data ◽  
Low Dose ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Adsorption Efficiency ◽  
Fixed Bed Column ◽  
Flow Rates ◽  
Adsorptive Removal ◽  
Reactive Blue 19 ◽  
Pseudo Second Order

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.

Microwave induced activated carbon for the removal of metal ions in fixed-bed column study: modelling and mechanisms

2021 ◽  
Vol 221 ◽  
pp. 139-151
Author(s):  
Omar S.A. Al-Khazrajy ◽  
Salam A. Mohammed ◽  
Omaimah Al-Musallami ◽  
Zahour Al-Rawahi ◽  
Emad Yousif
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Fixed Bed ◽  
Fixed Bed Column ◽  
Column Study ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

Adsorption characteristics of methylene blue onto agricultural wastes lotus leaf in bath and column modes

2011 ◽  
Vol 64 (3) ◽  
pp. 654-660 ◽  
Author(s):  
Xiuli Han ◽  
Wei Wang ◽  
Xiaojian Ma
Keyword(s):  
Methylene Blue ◽  
Fixed Bed ◽  
Isotherm Models ◽  
Column Experiments ◽  
Fixed Bed Column ◽  
Lotus Leaf ◽  
Bed Height ◽  
Column Adsorption ◽  
Equilibrium Data ◽  
Leaf Powder

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.

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