scholarly journals Modified Biopolymer Adsorbents for Column Treatment of Sulfate Species in Saline Aquifers

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2408
Author(s):  
Mostafa Solgi ◽  
Lope G. Tabil ◽  
Lee D. Wilson
Keyword(s):  
Adsorption Capacity ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Maximum Adsorption Capacity ◽  
Adsorption Parameters ◽  
Sulfate Adsorption ◽  
Specific Flow ◽  
Fixed Bed Column ◽  
Sulfate Removal ◽  
Column System

In the present study, variable forms of pelletized chitosan adsorbents were prepared and their sulfate uptake properties in aqueous solution was studied in a fixed-bed column system. Unmodified chitosan pellets (CP), cross-linked chitosan pellets with glutaraldehyde (CL–CP), and calcium-doped forms of these pellets (Ca–CP, Ca–CL–CP) were prepared, where the removal efficiencies and breakthrough curves were studied. Dynamic adsorption experiments were conducted at pH 4.5 and 6.5 with a specific flow rate of 3 mL/min, fixed-bed height of 200 mm, and an initial sulfate concentration of 1000 mg/L. Breakthrough parameters demonstrated that Ca–CP had the best sulfate removal among the adsorbents, where the following adsorption parameters were obtained: breakthrough time (75 min), exhaust time (300 min), maximum sulfate adsorption capacity (qmax; 46.6 mg/g), and sulfate removal (57%) at pH 4.5. Two well-known kinetic adsorption models, Thomas and Yoon-Nelson, were fitted to the experimental kinetic data to characterize the breakthrough curves. The fixed-bed column experimental results were well-fitted by both models and the maximum adsorption capacity (46.9 mg/g) obtained was for the Ca–CP adsorbent. A regeneration study over four adsorption-desorption cycles suggested that Ca–CP is a promising adsorbent for sulfate removal in a fixed-bed column system.

scholarly journals H-Clinoptilolite as an Efficient and Low-Cost Adsorbent for Batch and Continuous Gallium Removal from Aqueous Solutions

2021 ◽  
Author(s):  
P. Sáez ◽  
A. Rodríguez ◽  
J. M. Gómez ◽  
C. Paramio ◽  
C. Fraile ◽  
...  
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Fixed Bed ◽  
Particle Size Effect ◽  
Breakthrough Curves ◽  
Maximum Adsorption Capacity ◽  
Fixed Bed Column ◽  
Gallium Concentration ◽  
Best Fit

AbstractIn this paper, the gallium (III) ions’ adsorption onto protonated clinoptilolite (H-CLP) was investigated both in batch and fixed-bed column experiments. Regarding batch experiments, the influence of some parameters such as adsorbent dosage, size particle, and temperature was studied, determining that a dosage of 10 g/L for an initial pollutant concentration of 40 mg/L leads to a removal percentage over 85% regardless of particle size and temperature. On the other hand, adsorption of gallium onto H-CPL is an endothermic and spontaneous process in the studied temperature range, concluding that the maximum adsorption capacity was 16 mg/g for 60 °C. Concerning to the effect of the presence of other cations in solution, such as Na+, K+, or Ca2+, gallium adsorption capacity only drops by 20%, although the initial concentration of other cations in the solution is 50 times higher than gallium concentration. This means that clinoptilolite has a high affinity for gallium which can be very favorable for further selectivity tests. A crucial factor for this high selectivity could be the protonation of clinoptilolite which allows working without modifying the pH of the aqueous solution with acid. In the fixed-bed experiments, breakthrough curves were obtained, and the effect of operation variables was determined. A breakpoint value of 254 min for 64 g of adsorbent and flow rate of 9.0 mL/min (7.0 BV/h) were obtained, when treating a pollutant volume of 33 BV. Additionally, the breakthrough curves were fitted to different models to study the particle size effect, being the best fit corresponding to the Adams–Bohart model. This fact confirmed the influence of particle size on adsorption kinetics. Graphical Abstract

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 Competitive Fixed-Bed Adsorption of Pb(II), Cu(II), and Ni(II) from Aqueous Solution Using Chitosan-Coated Bentonite

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Wan-Chi Tsai ◽  
Mark Daniel G. de Luna ◽  
Hanna Lee P. Bermillo-Arriesgado ◽  
Cybelle M. Futalan ◽  
James I. Colades ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Maximum Adsorption Capacity ◽  
Operational Parameters ◽  
Initial Concentration ◽  
Bed Height ◽  
Fixed Bed Adsorption ◽  
Ternary Metal

Fixed-bed adsorption studies using chitosan-coated bentonite (CCB) as adsorbent media were investigated for the simultaneous adsorption of Pb(II), Cu(II), and Ni(II) from a multimetal system. The effects of operational parameters such as bed height, flow rate, and initial concentration on the length of mass transfer zone, breakthrough time, exhaustion time, and adsorption capacity at breakthrough were evaluated. With increasing bed height and decreasing flow rate and initial concentration, the breakthrough and exhaustion time were observed to favorably increase. Moreover, the adsorption capacity at breakthrough was observed to increase with decreasing initial concentration and flow rate and increasing bed height. The maximum adsorption capacity at breakthrough of 13.49 mg/g for Pb(II), 12.14 mg/g for Cu(II), and 10.29 mg/g for Ni(II) was attained at an initial influent concentration of 200 mg/L, bed height of 2.0 cm, and flow rate of 0.4 mL/min. Adsorption data were fitted with Adams-Bohart, Thomas, and Yoon-Nelson models. Experimental breakthrough curves were observed to be in good agreement (R2>0.85andE%<50%) with the predicted curves generated by the kinetic models. This study demonstrates the effectiveness of CCB in the removal of Pb(II), Cu(II), and Ni(II) from a ternary metal solution.

Modeling of chromium (VI) adsorption from aqueous solutions using Jordanian Zeolitic Tuff

2017 ◽  
Vol 75 (9) ◽  
pp. 2064-2071 ◽  
Author(s):  
Reyad Al Dwairi
Keyword(s):  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Size Fraction ◽  
Breakthrough Curves ◽  
Zeolitic Tuff ◽  
Fixed Bed Column ◽  
Grain Sizes ◽  
Chromium Vi

The probable use of Jordanian natural zeolitic tuff in wastewater treatment as natural adsorbent for the removal of Cr (VI) ions from aqueous solution in continuous fixed bed columns was tested experimentally and theoretically. The tested zeolitic tuff was obtained from Al Hala volcano (HZ) located in southern part of Jordan and subjected to crushing and sieving only without any further treatment. Experimentally the HZ grains were packed in a fixed bed column. The used grain sizes are HZ1 (1.0–0.60 mm) and HZ2 (0.60–0.30 mm). The adsorption capacity was evaluated using breakthrough curves and by applying the Thomas and Yoon and Nelson models. The Thomas model analysis of the measured breakthrough curves revealed that the adsorbent HZ2 has a higher adsorption capacity to Cr (VI) ions (56.3 mg/g) than HZ1 (35.5 mg/g). The time elapsed to reach 50% breakthrough was determined by the Yoon and Nelson model. The time to reach 50% breakthrough is 318.78 min and 368.18 min for HZ1 and HZ2, respectively. The research results indicate that the small size fraction (HZ2) is more suitable and effective as adsorbent material than the size fraction (HZ1) due to its high surface area.

Removal of Cesium from Aqueous Solution Using PAN-Based Ferrocyanide Composite Spheres: Adsorption on a Fixed-Bed Column

2014 ◽  
Vol 496-500 ◽  
pp. 259-263 ◽  
Author(s):  
Zhi Hui Du ◽  
Ming Chun Jia ◽  
Jin Feng Men
Keyword(s):  
Flow Rate ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Model Parameters ◽  
Maximum Adsorption Capacity ◽  
Fixed Bed Column ◽  
Composite Adsorbents ◽  
Bed Height ◽  
Cobalt Hexacyanoferrates ◽  
Good Agreement

Two spherical composite adsorbents namely polyacrylonitrilepotassium cobalt hexacyanoferrates (PAN-KCoCF) and polyacrylonitrilepotassium nickel hexacyanoferrates (PAN-KNiCF) were synthesized. The effects of liquid flow rate, bed height and presence of other cations on the adsorption of cesium were investigated by conducting fixed-bed columns. The results showed that the column performed well at lowest flow rate for PAN-KNiCF. Flow rate examined had little influence on the adsorption of PAN-KCoCF. The breakthrough time decreased with decreasing bed height for both PAN-KCoCF and PAN-KNiCF. In addition, the existence of K+, Na+, NH4+, Ca2+and Mg2+in solution caused a reduction of maximum adsorption capacity for both of the composites. The bed depth service time (BDST) model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated. Good agreement of the experimental breakthrough curves with the model predictions was observed.

scholarly journals Batch and Fixed-Bed Column Studies on Palladium Recovery from Acidic Solution by Modified MgSiO3

2020 ◽  
Vol 17 (24) ◽  
pp. 9500
Author(s):  
Cosmin Vancea ◽  
Maria Mihailescu ◽  
Adina Negrea ◽  
Giannin Mosoarca ◽  
Mihaela Ciopec ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Fixed Bed ◽  
Recovery Process ◽  
Dynamic Regime ◽  
Bet Surface Area ◽  
High Price ◽  
Maximum Adsorption Capacity ◽  
Column Studies ◽  
Fixed Bed Column ◽  
Column Adsorption

Effective recovery of palladium ions from acidic waste solutions is important due to palladium’s intensive usage as a catalyst for different industrial processes and to the high price paid for its production from natural resources. In this paper, we test the ability of a new adsorbent, MgSiO3 functionalized by impregnation with DL-cysteine (cys), for palladium ion recovery from waste solutions. The Brunauer–Emmett–Teller (BET) surface area analysis, Barrett–Joyner–Halenda (BJH) pore size and volume analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and Fourier-Transformed Infrared (FTIR) spectroscopy have been performed to characterize this material. Firstly, the maximum adsorption capacity of the new obtained material, MgSiO3-cys, in batch, was studied. To establish the adsorption mechanism, the obtained experimental data were fitted using the Langmuir, Freundlich and Sips adsorption isotherms. Studies on the adsorption of palladium ions on the synthesized material were performed in a dynamic regime, in a fixed-bed column. The Pd(II) recovery mechanism in the dynamic column regime was established based on Bohart–Adams, Yoon–Nelson, Thomas, and Clark models. The obtained equilibrium adsorption capacity was 9.3 (mg g−1) in static regime (batch) and 3 (mg g−1) in dynamic regime (column). The models that best describe the Pd(II) recovery process for batch and column adsorption are Sips and Clark, respectively.

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.

scholarly journals Adsorption of phosphorus by alkaline Tunisian soil in a fixed bed column

2018 ◽  
Vol 78 (4) ◽  
pp. 751-763 ◽  
Author(s):  
Rihab Beji ◽  
Wissem Hamdi ◽  
Aida Kesraoui ◽  
Mongi Seffen
Keyword(s):  
Regression Analysis ◽  
Adsorption Capacity ◽  
Flow Rate ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Alkaline Soil ◽  
Fixed Bed Column ◽  
P Adsorption ◽  
Bed Height ◽  
P Concentration

Abstract The present study evaluates the phosphorus (P) adsorption by alkaline soil in fixed bed column mode operation. The effects of flow rate, bed height, and initial P concentration on breakthrough curves were evaluated. Data confirmed that both the breakthrough and exhaustion time increased in parallel with the rise in bed height and the decline in flow rate and initial P concentration. The adsorption capacity was observed to increase with decreasing flow rate and bed height and increasing initial concentration. Moreover, continuous adsorption experiments were conducted using three salts (NaCl, KCl and CaCl2) with the same concentration (0.01 M) to investigate the P adsorption behavior in saline conditions. The results showed that all three salts improve the P adsorption in the soil column. Consequently, the bed performance was significantly enhanced with salts addition. The maximum adsorption capacity of 13.47 mg g−1 for P, 16.13 mg g−1 for P-NaCl, 22.10 mg g−1 for P-KCl, 30.05 mg g−1 for P-CaCl2 was attained at an initial influent concentration of 300 mg g−1, bed height of 22 cm, and flow rate of 10 mL min−1. TheCaCl2 addition was therefore the most effective in increasing P adsorption. Thomas, Yoon-Nelson and Clark models were applied to experimental results to forecast the breakthrough curves by nonlinear regression analysis. Meanwhile, the bed depth service time model was employed to examine the effective model parameters in scaling up the process using linear regression analysis. The values of correlation coefficient (R2) and the sum of squared error evidenced that the Thomas model is the most appropriate model to fit the experimental data. The reusability experiment showed that the adsorbent material still had high P adsorption capacity, and tolerable desorption efficiency.

scholarly journals Study on Reactive Blue Adsorption on Raw and Modified Wheat Straw Using Fixed-Bed Column

2021 ◽  
Vol 24 (1) ◽  
pp. 1-7
Author(s):  
Alaa Taha ◽  
Khalid M. Mousa
Keyword(s):  
Wheat Straw ◽  
Adsorption Capacity ◽  
Flow Rate ◽  
Low Cost ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Blue Dye ◽  
Time Model ◽  
Fixed Bed Column ◽  
Bed Height

The intention of this study was to explore the efficiency and feasibility of adsorption of Reactive Blue dye (H3R) used in textile industries using Raw wheat straw (RWS) and Modified wheat straw (MWS) as a low-cost adsorbent. Wheat straw was modified using cationic surfactant (CTAB) to study the improvement of dye removal. The properties of Raw and Modified wheat straw are studied by means of Fourier transform infrared (FTIR) and scanning electron microscope (SEM) analyses to determine the functional groups and the nature of their surface. Continuous experiments were done by fixed-bed column to study the characteristics of the breakthrough curve using different bed heights and flow rates. Results showed that the breakthrough time increases with increasing bed height and decreasing flow rate, in turn results into higher removal capacity. Results also showed a higher flow rate lead a lower adsorption capacity due to insufficient residence time. Bed depth service time model (BDST), Adam-Bohart and Thomas models were used to predict the breakthrough curves and to determine the adsorption capacity of the column. The highest bed capacity of 12.95 and 32.2 mg/g for MWS was obtained using 10 mg/L, 10 cm bed height at 10 mL/min and 30 mL/min respectively.

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.

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