scholarly journals Experimental and modeling study of water defluoridation using waste granular brick in a continuous up-flow fixed bed

2020 ◽  
Vol 26 (2) ◽  
pp. 190506-0
Author(s):  
Ziad T. Abd Ali ◽  
Zainab Z. Ismail
Keyword(s):  
Health Hazard ◽  
Economic Value ◽  
Fixed Bed ◽  
Freundlich Isotherm ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Continuous Mode ◽  
Batch Mode ◽  
Initial Ph ◽  
Modeling Study

Contamination of surface and groundwater with excessive concentrations of fluoride is of significant health hazard. Adsorption of fluoride onto waste materials of no economic value could be a potential approach for the treatment of fluoride-bearing water. This experimental and modeling study was devoted to investigate for the first the fluoride removal using unmodified waste granular brick (WGB) in a fixed bed running in continuous mode. Characterization of WGB was carried out by FT-IR, SEM, and EDX analysis. The batch mode experiments showed that they were affected by several parameters including contact time, initial pH, and sorbent dosage. The best values of these parameters that provided maximum removal percent (82%) with the initial concentration of F-1 ions (10 mg/L) and agitation speed (200 rpm) were 90 min, 8, and 3 g/100 mL, respectively. The experimental data were found to fit the Freundlich isotherm model. The maximum adsorption capacity of fluoride on WGB was 1.1 mg/g. The continuous mode experiments clearly confirmed the important role of WGB bed in hindering and confining the propagation of the fluoride-loaded plume as well as there was a very good matching (RMSE ≤ 0.0398) with the predicted results obtained by the simulated mathematical model using COMSOL Multiphysics 3.5a software.

Adsorptive removal of PAR and Arsenazo-III from radioactive waste solutions by modified sugarcane bagasse as eco-friendly sorbent

2020 ◽  
Vol 108 (10) ◽  
pp. 785-798
Author(s):  
Ezzat A. Abdel-Galil ◽  
Marwa A. Eid ◽  
Ahmed M. Shahr El-Din
Keyword(s):  
Radioactive Waste ◽  
Sugarcane Bagasse ◽  
Liquid Radioactive Waste ◽  
Freundlich Isotherm ◽  
Arsenazo Iii ◽  
Maximum Adsorption Capacity ◽  
Free Energy Of Adsorption ◽  
Batch Mode ◽  
Initial Ph ◽  
Intra Particle Diffusion

AbstractIn this paper, sugarcane bagasse (SCB) was modified using phosphoric acid. The modified sugarcane bagasse (MSCB) has been used to remove 4-(2-pyridylazo)resorcinol (PAR) and Arsenazo-III (Ar-III) from liquid radioactive waste. The surface morphology and functional groups of the MSCB were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption ability of MSCB has been tested by batch mode through some relevant factors like initial pH, reaction time, initial coloring reagents (PAR and Ar-III) concentrations, and adsorbent weight. At adsorption equilibrium time 180 min and pH values of 3 and 1 for PAR and Ar-III; the maximum removal (%) for both PAR and Ar-III were 93 and 57%, respectively. The adsorption isotherm data are representative well to Freundlich isotherm model. The mean free energy of adsorption, E (kJ/mol), has been estimated as 5.75 and 2.28 kJ/mol for PAR and Ar-III, respectively, which suggests that the adsorption occurred physically. The maximum adsorption capacity of MSCB for PAR and Ar-III is 96.62 and 15.18 mg/g, respectively. The adsorption kinetics are better fitted by the pseudo-second-order model. The partial film along with intra-particle diffusion controlled the diffusion of coloring reagents from the solution bulk to the particle interior pores. Application of MSCB for removing PAR and Ar-III from simulated liquid radioactive waste containing U(VI) and Th(VI) ions has been achieved successfully.

scholarly journals A new adsorbent for fluoride removal: The utilization of sludge waste from electrocoagulation as adsorbent

2015 ◽  
Vol 17 (1) ◽  
pp. 186-197 ◽  
Keyword(s):  
Particle Size ◽  
Contact Time ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Solution Temperature ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Batch Mode ◽  
Adsorption Removal ◽  
Adsorbent Dose

<div> <p>This work investigated the potential of calcined electrocoagulation sludge (CES) within metals hydroxide generated during removal of boron using Al electrode for adsorption of fluoride from aqueous solution. The effects of contact time, pH of the solution (2-10), stirrer speed (50-450 rpm), initial concentration (5-100<br /> mg l<sup>-1</sup>), adsorbent dose (1-4 mg l<sup>-1</sup>), solution temperature (293-333 K) and particle size (0.125-1000 &micro;m) on fluoride removal were investigated. All the experiments were carried out by batch mode. It was found that the maximum adsorption takes place within 2 h at pH 6.0. The adsorption removal increased with increase in the adsorbent dose, but decreased with increase in fluoride concentration. It was found that the adsorption removal decreases with increase in temperature, which showed that the adsorption process was exothermic in nature. The decrease in particle size increased fluoride removal efficiency. The maximum adsorption capacity (q<sub>m</sub>) increased from 45.5 to 124.6 mg g<sup>-1</sup> when the adsorbent dosage was adjusted to 1 instead of 4 g l<sup>-1</sup>. The Freundlich isotherm and Langmuir isotherm were used to fit the data of equilibrium experiments. The adsorption data fitted well into the linearly transformed Langmuir equation. The efficiency of CES to remove fluoride was found to be 99.99% at pH 6, contact time for 2 h, dose of 4 g l<sup>-1</sup>, when 25 mg l<sup>-1</sup> of fluoride was present in 100 ml of water. Comparison with literature reported values of q<sub>m</sub>, it was found that CES was an attractive adsorbent.</p> </div> <p>&nbsp;</p>

scholarly journals Adsorption Study of Cu2+ Ions from Aqueous Solutions by Bael Flowers (Aegle marmelos)

2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Low Cost ◽  
Sem Analysis ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Aegle Marmelos ◽  
Batch Mode ◽  
Initial Ph

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.

Adsorption of cadmium(II) from aqueous solution onto activated carbon

1997 ◽  
Vol 35 (7) ◽  
pp. 205-211 ◽  
Author(s):  
R. Leyva-Ramos ◽  
J. R. Rangel-Mendez ◽  
J. Mendoza-Barron ◽  
L. Fuentes-Rubio ◽  
R. M. Guerrero-Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Carbon Surface ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Ph Values ◽  
Average Percent Deviation ◽  
Initial Ph

The adsorption isotherm of cadmium on activated carbon was measured in a batch adsorber. Effects of temperature and solution pH on the adsorption isotherm were investigated by determining the adsorption isotherm at temperatures of 10, 25, and 40°C and at initial pH values from 2 to 8. Langmuir isotherm better fitted the experimental data since the average percent deviation was lower than with the Freundlich isotherm It was noticed that the amount of Cd2+ adsorbed was reduced about 3 times by increasing the temperature from 10 to 40°C. It was found that Cd2+ was not adsorbed on activated carbon at pH of 2 or lower and that Cd2+ was precipitated out as Cd(OH)2 at pH values above 9. Maximum adsorption capacity was observed at pH of 8 and the adsorption capacity was decreased about 12 times by reducing the initial pH from 8 to 3. According to the cadmium speciation diagram the predominant species below pH of 8 is Cd2+. Thus, cadmium was adsorbed on the activated carbon surface as Cd2+. It was concluded that the adsorption capacity is a strong function of pH and temperature.

scholarly journals Removing Thallium (I) Ion from Aqueous Solutions Using Modified ZnO Nanopowder

2016 ◽  
Vol 11 (7) ◽  
pp. 3777-3788 ◽  
Author(s):  
H. Dashti Khavidaki ◽  
M. H. Fekri
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Phosphate Solution ◽  
Experimental Conditions ◽  
Batch Mode ◽  
Solution Interface ◽  
Zno Nanopowder ◽  
Exothermic Process ◽  
Initial Ph ◽  
Sodium Phosphate Solution

In this study, the adsorption of thallium (I) ion as a dangerous pollutant from aqueous solution onto modified ZnO nanopowder as a fairly cheap adsorbent has been examined in batch mode. It was known that modification of the adsorbent was necessary to reach a significant adsorption percentage. The adsorbent used here was modified by sodium phosphate solution. The effect of experimental conditions such as initial pH of solution, contact time, adsorbent dosage, initial concentration of thallium and temperature is studied. The results showed the dependence of the adsorption percentage to these conditions specially its pH. The maximum adsorption percentage of Tl (I) ions at 25±1oC was 92.8%. Freundlich isotherm model provided a better fit with the experimental data than Langmuir and Temkin isotherm models by high correlation. Separation factor, RL, values showed that modified ZnO nanopowder was favorable for the adsorption of Tl (I) ion. The negative value of ΔH0 showed that Tl (I) sorption is an exothermic process and the negative value of ΔS0 represented that there is a little decrease of randomness at the solid-solution interface during sorption.

scholarly journals Application of Chemically Modified Industrial Slag to As(III) Adsorption from Wastewater: Kinetics and Mass Transfer Analysis

2021 ◽  
Vol 68 (2) ◽  
pp. 341-354
Author(s):  
Arijit Dutta Gupta ◽  
Vivek Jaiswal ◽  
Vivek Bhadauria ◽  
Harinder Singh
Keyword(s):  
Mass Transfer ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Transfer Coefficients ◽  
Uptake Capacity ◽  
Brick Kiln ◽  
Batch Mode ◽  
Chemically Modified ◽  
Adsorption Data ◽  
Pseudo Second Order

In the present study, brick kiln slag (BKS) has been utilized for low concentration As(III) adsorption in batch mode. BKS was modified with H2SO4 (SA) and NaOH (SB) for enhancing As(III) uptake capacity. Maximum adsorption capacity (13.7 mg/g) was observed for SA at 298 K, pH = 7.0, adsorbent dose = 0.3 g and time = 70 min which was 1.4 times higher than that of SB. Adsorption data modelled into Freundlich isotherm and pseudo-second-order kinetics. Mass transfer coefficients decreased with increase in As(III) concentration. Film diffusion significantly dominated the adsorption of As(III) ions irrespective of the initial concentration. Dimensionless Sherwood number (Sh) interrelated As(III) concentration (Co) as: Sh = 2.97(Co)–0.376, Sh = 4.12(Co)–0.215, Sh = 4.83(Co)–0.588 for H2SO4 modified, NaOH modified and native slag respectively. Low temperature (298 K) favoured As(III) adsorption (based on ΔG° value). Therefore, the modified slag can be used as an effective adsorbent for As(III) remediation from groundwater.

Application of annealed red mud to Mn2+ ion adsorption from aqueous solution

2016 ◽  
Vol 73 (11) ◽  
pp. 2761-2771 ◽  
Author(s):  
Hongliang Chen ◽  
Juan Zheng ◽  
Zhongqiong Zhang ◽  
Qian Long ◽  
Qiuyun Zhang
Keyword(s):  
Aqueous Solution ◽  
Red Mud ◽  
Freundlich Isotherm ◽  
Physicochemical Characteristics ◽  
Point Of Zero Charge ◽  
Maximum Adsorption Capacity ◽  
Adsorption Effect ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue ◽  
Initial Ph

Physicochemical characteristics and Mn2+ adsorption of annealed red mud were investigated in this study. The annealing temperature (105–900 °C) changed the mineralogical components and the point of zero charge of red mud. By comparison, annealed red mud at 700 °C (ARM700) had a better adsorption effect than other annealed samples, associated with the activated components of available Fe2O3, Al2O3, SiO2 and Na5Al3(SiO4)3CO3 (natrodavyne). The removal efficiency of Mn2+ by ARM700 was dependent on initial pH, contact time, and initial Mn2+ concentration of aqueous solution and was ∼56.5% with initial Mn2+ concentration 385 mg/L at initial pH &gt; 5. The kinetics process was predicted better by the pseudo-second-order model. The Langmuir isotherm displayed a better fitting model than the Freundlich isotherm and the Mn2+ maximum adsorption capacity of ARM700 was 88.3 mg/g. The competing effects of Cu2+ and Zn2+ on Mn2+ removal were most obvious. There was efficient Mn2+ removal at the application of ARM700 to the leachate of electrolytic manganese residue.

scholarly journals Amine functionalized and Fe3O4 incorporated activated carbon for bisphenol-A separation

2019 ◽  
Vol 79 (9) ◽  
pp. 1755-1765 ◽  
Author(s):  
Drishti Bhatia ◽  
Sakshi Batra ◽  
Dipaloy Datta
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Bisphenol A ◽  
Fixed Bed ◽  
Industrial Effluent ◽  
Aliquat 336 ◽  
Continuous Mode ◽  
Batch Mode ◽  
Fixed Bed Adsorption ◽  
Gibb’S Free Energy

Abstract Activated carbon (AC) is the most commonly used adsorbent for water purification, although the dispersive nature of AC in aqueous solution poses a serious problem. To overcome this limitation, AC was magnetized with iron oxide using iron salts as precursor. Further to enhance its effectiveness, it was impregnated with Aliquat 336. Different characterization techniques (Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), along with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD)) were used to analyze the adsorbent. Furthermore, the value of the pH at which the overall charge on the surface of the adsorbent is neutral was found by pH drift method. The modified form of the activated carbon was used to treat the aqueous solution of bisphenol-A in the batch as well as in the continuous mode of operation. In batch mode, the data were validated using equilibrium and kinetic models, and in continuous mode, data were fitted with the Thomas, Adams-Bohart, and bed depth service time (BDST) fixed bed adsorption models. Also, the changes in Gibb's free energy, enthalpy, and entropy were estimated from the temperature study. The design of an adsorption column is proposed to treat 10,000 L/day of an industrial effluent containing BPA.

The Study of Copper (II) Removal from Aqueous Solutions by Adsorption Using Corn Stalk Material

2012 ◽  
Vol 610-613 ◽  
pp. 1950-1953
Author(s):  
Zheng Jun Gong ◽  
Wenbo Zhou ◽  
Zhong Ping Qiu
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Corn Stalk ◽  
Absorption Process ◽  
Optimum Conditions ◽  
Batch Mode ◽  
Langmuir Adsorption ◽  
Initial Ph

In this study, removal of copper(Ⅱ) from aqueous solutions was examined using corn stalk. In the batch mode adsorption studies, the effects of initial pH and contact time on the copper(Ⅱ) adsorption by the corn stalk have been studied. The results show that: the pH 6.0 and contact time 8 hrs is optimum conditions of this absorption process when the dosage of corn stalk is 0.1g. In the isotherm studies, the Langmuir and Freundlich isotherm models were applied. The R2 of the Langmuir and Freundlich isotherm are 0.981 and 0.944 respectively. The Langmuir adsorption capacity Qmax is 54.05 mg/g. The goodness of fitness was obtained with the Langmuir and Freundlich adsorption isotherms.

scholarly journals Study the Use of Activated Carbon and Bone Char on the Performance of Gravity Sand-Bag Water Filter

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 868
Author(s):  
Eric Fung ◽  
Ken I. Johnson ◽  
Wenqi Li ◽  
William Borges ◽  
Kai Chi ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
High Surface ◽  
High Surface Area ◽  
Synergetic Effect ◽  
Freundlich Isotherm ◽  
Surface Characteristics ◽  
Isotherm Models ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Bag Filter

In this study, granulated activated charcoal (GAC) and bio charcoal (BC) is used as a filler in P3 biosand bag filter to study their filtration performance against a range of fluoride impurities from 1–1400 mg/L. A set of experiments are done to analyze the filtration efficiency of the sandbag filter against fluoride impurities after incorporating different amounts (e.g., 0.2, 2 kg) and a combination of GAC and BC. A combination of filler GAC and BC (1 kg each) have exhibited excellent results with 100% fluoride removal efficiency against 5 mg/L fluoride impurities for an entire experimental time of 165 min. It is because of the synergetic effect of adsorption caused by the high surface area (739 m2/g) of GAC and hydroxyapatite groups in BC. The data from remediation experiments using individual GAC and BC are fitted into the Langmuir and Freundlich Isotherm Models to check their adsorption mechanism and determine GAC and BC’s maximum adsorption capacity (Qm). The remediation data for both GAC and BC have shown the better fitting to the Langmuir Isotherm Model with a high R2 value of 0.994 and 0.970, respectively, showing the excellent conformity with monolayer adsorption. While the GAC and BC have presented negative Kf values of −1.08 and −0.72, respectively, for Freundlich Model, showing the non-conformity to multilayer adsorption. The Qm values obtained from Langmuir Model for GAC is 6.23 mg/g, and for BC, it is 9.13 mg/g. The pH study on adsorption efficiency of individual GAC and BC against 5 mg/L of fluoride impurities indicates the decrease in removal efficiency with an increase in pH from 3 to 9. For example, BC has shown removal efficiency of 99.8% at pH 3 and 99.5% at pH 9, while GAC has exhibited removal efficiency of 96.1% at pH 3 and 95.9% at pH 9. Importantly, this study presents the significance of the synergetic application of GAC and BC in the filters, where GAC and BC are different in their origin, functionalities, and surface characteristics.

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