Enhancement of the adsorption properties of two natural bentonites by ion exchange: equilibrium, kinetics and thermodynamic study

Clay Minerals ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 132-141
Author(s):  
Ali Boukhemkhem ◽  
Alejandro H. Pizarro ◽  
Carmen B. Molina
Keyword(s):  
Ion Exchange ◽  
Point Of Zero Charge ◽  
Exchange Equilibrium ◽  
Anionic Dyes ◽  
X Ray ◽  
Intraparticle Diffusion Model ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Bentonite Clays ◽  
Adsorption Desorption

ABSTRACTIn this investigation, Maghnia (Ma) and Mostaganem (Ms) bentonite clays, mined from west Algeria, with no prior affinity for anionic dyes, were modified by simple ion exchange with aqueous Fe3+ solutions, followed by calcination at 500°C. The resulting materials, Fe-Ma and Fe-Ms, respectively, were employed as adsorbents for methyl orange. The starting materials and the two adsorbents were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, Brunauer–Emmett–Teller specific surface area and X-ray fluorescence and by determining the point of zero charge. The effects of various variables, such as initial dye concentration, contact time, adsorbent dose, initial pH and adsorption temperature, were studied. The kinetics were well described by the pseudo-second-order model and the mechanism was determined from the intraparticle diffusion model, while corresponding isotherms fitted better to the Freundlich model. Thermodynamic parameters showed that the adsorption process was endothermic, spontaneous and physical in nature, accompanied by an increase of entropy.

scholarly journals Antimony Removal from Water by a Chitosan-Iron(III)[ChiFer(III)] Biocomposite

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 351 ◽  
Author(s):  
Byron Lapo ◽  
Hary Demey ◽  
Tanya Carchi ◽  
Ana Sastre
Keyword(s):  
Material Characterization ◽  
Point Of Zero Charge ◽  
Iron Oxyhydroxide ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Chitosan Matrix ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Order Rate Equation

The presence of antimony(III) in water represents a worldwide concern, mainly due to its high toxicity and carcinogenicity potential. It can be separated from water by the use of sustainable biopolymers such as chitosan or its derivatives. The present study applied chitosan modified with iron(III) beads to Sb(III) removal from aqueous solutions. The resulting material performed with a high adsorption capacity of 98.68 mg/g. Material characterization consisted of Raman spectroscopy (RS), X-ray diffraction (XRD), scanning electron microscope observations (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and point of zero charge (pHpzc). The adsorption study included pH study, effect of initial concentration, kinetics, ion effect, and reusability assessment. The RS, XRD, and FTIR results indicated that the main functional groups in the composite were related to hydroxyl and amino groups, and iron oxyhydroxide species of α-FeO(OH). The pHpzc was found to be 7.41. The best adsorption efficiency was set at pH 6. The equilibrium isotherms were better fitted with a non-linear Langmuir model, and the kinetics data were fitted with a pseudo-second order rate equation. The incorporation of iron into the chitosan matrix improved the Sb(III) uptake by 47.9%, compared with neat chitosan (CS). The material did not exhibit an impact in its performance in the presence of other ions, and it could be reused for up to three adsorption–desorption cycles.

scholarly journals Separate As(V) from solution by mesoporous Y-Al binary oxide: batch experiments

2017 ◽  
Vol 77 (4) ◽  
pp. 871-879
Author(s):  
Hang Liu ◽  
Caiyun Han ◽  
Liu Yang ◽  
Dekun Liu ◽  
Yongming Luo
Keyword(s):  
Point Of Zero Charge ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Impregnation Method ◽  
Batch Experiments ◽  
Adsorption Performance ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Desorption

Abstract Contaminant arsenic(V) has been regarded as one of the top-priority pollutants to remove from water. In this contribution, different mesoporous Y-Al binary oxides were prepared by the wet impregnation method via varying the molar ratio of Y/Al in the range of 0.029 to 0.116. The manufactured materials were employed as adsorbent to separate arsenic(V) from water. The adsorbent was characterized by N2 adsorption–desorption isotherm, point of zero charge (PZC) and Fourier transform infrared (FT-IR). Furthermore, the effect of experimental parameters on adsorption performance was evaluated by batch experiments, including the molar ratio of Y/Al, adsorbent dosages and contact time, initial concentration, initial pH and temperature. The results indicated that the adsorbent presented an optimal adsorption performance for As(V) uptake when the molar ratio of Y/Al was 0.058. The obtained experimental data were best fitted by Langmuir isotherm and the maximum adsorption capacity was 60.93 mg/g at pH 6.6 ± 0.1. Additionally, according to the results of adsorption kinetics, it was pronounced that adsorption process was complied with pseudo-second-order model. The adsorption thermodynamic suggested that the adsorption of As(V) is endothermic and spontaneous natural. Moreover, based on the results of FT-IR, PZC and initial pH, it is demonstrated that ion-exchange and electrostatic interaction were the dominating adsorption mechanism.

scholarly journals Husk of Agarwood Fruit-Based Hydrogel Beads for Adsorption of Cationic and Anionic Dyes in Aqueous Solutions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong
Keyword(s):  
Aqueous Solutions ◽  
Selective Adsorption ◽  
Order Model ◽  
Anionic Dyes ◽  
Adsorption Selectivity ◽  
Hydrogel Beads ◽  
Batch System ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.

Preparation of cationic waste paper and its application in poisonous dye removal

2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan
Keyword(s):  
Low Cost ◽  
Aqueous Suspension ◽  
Order Kinetic ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Experimental Conditions ◽  
Adsorption Models ◽  
Acid Orange ◽  
Initial Ph ◽  
Pseudo Second Order

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously.

Behaviours of direct yellow 12 adsorption on mesoporous carbons with different pore geometries

2018 ◽  
Vol 2017 (1) ◽  
pp. 219-228
Author(s):  
Fengling Liu ◽  
Ziyan Guo ◽  
Hui Qiu ◽  
Xia Lu ◽  
Hua Fang ◽  
...  
Keyword(s):  
Mesoporous Carbons ◽  
X Ray Diffraction ◽  
Pore Characteristics ◽  
X Ray ◽  
Transmission Electron ◽  
Cylindrical Pores ◽  
Pseudo Second Order ◽  
Hexagonally Ordered ◽  
Adsorption Desorption ◽  
Interconnected Pore

Abstract Four kinds of mesoporous carbons, C1-h-w, C2-h-h, C3-s-w, and C4-s-h, with different pore geometries were prepared and characterised, and their adsorption behaviours with aqueous direct yellow 12 (DY-12) were investigated. The results of X-ray diffraction and transmission electron microscopy show that C1-h-w and C3-s-w have wormlike pore characteristics, whereas C2-h-h and C4-s-h have 2-D hexagonally arranged pores. According to the N2 adsorption/desorption results, the specific surface area of C1-h-w (1,378 m2/g) is the largest among the four carbons. The adsorption isotherms could be effectively fitted using the Langmuir model. The maximum adsorption amounts of C1-h-w, C2-h-h, C3-s-w and C4-s-h are 0.968 mmol/g, 0.726 mmol/g, 0.161 mmol/g and 0.156 mmol/g, respectively. The pseudo-second-order rate constants of C1-h-w (39.8 g/(mmol·min)) and C2-h-h (7.28 g/(mmol·min)) are substantially larger than those of C3-s-w (0.0046 g/(mmol·min)) and C4-s-h (0.014 g/(mmol·min)), indicating that an open and interconnected pore geometry is favourable for DY-12 adsorption. Furthermore, DY-12 diffusion in 2-D hexagonally ordered cylindrical pores is superior to that in wormlike pores due to the smoothness of the channels in the former. External mass transfer and intraparticle diffusion both play roles in the adsorption process.

scholarly journals Efficient adsorption of Hg(II) from aqueous solution by N, S co-doped MnFe2O4@C magnetic nanoparticles

2020 ◽  
Vol 81 (6) ◽  
pp. 1273-1282 ◽  
Author(s):  
Hangdao Qin ◽  
Hao Cheng ◽  
Chenggui Long ◽  
Xiaogang Wu ◽  
Yanhong Chen ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Chemical Properties ◽  
Point Of Zero Charge ◽  
Simple Method ◽  
Transmission Electron ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Adsorption Desorption ◽  
Physical And Chemical ◽  
Co Doped

Abstract N, S co-doped MnFe2O4@C magnetic nanoparticles were successfully synthesized by a simple method involving the preparation of MnFe2O4 nanoparticles and subsequent pyrolysis treatment. The physical and chemical properties of MnFe2O4, MnFe2O4@C and MnFe2O4@C–NS nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), N2 adsorption–desorption and the pH at the point of zero charge. Their performances in the adsorption of Hg(II) from water were investigated. The adsorption process followed pseudo-second-order kinetics and the experimental data of equilibrium isotherms fitted well with the Langmuir model. MnFe2O4@C–NS showed the highest adsorption capacity of 108.56 mg/g, increasing more than 1.7 times compared to MnFe2O4. The enhanced adsorption performance was attributed to the larger specific surface area as well as the complexation of N and S ligands on the surface. The thermodynamic parameters of ΔH°, ΔS° and ΔG° at 30 °C were −24.39 kJ/mol, −0.046 kJ/mol K and −10.45 kJ/mol, respectively, which indicated that the adsorption of Hg(II) on MnFe2O4@C–NS was exothermic and spontaneous in nature. Moreover, MnFe2O4@C–NS showed superior selectivity towards Hg(II) compared with other metal ions generally present in mercury-containing industrial wastewater.

scholarly journals Environmentally Friendly Mesoporous Nanocomposite Prepared from Al-Dross Waste with Remarkable Adsorption Ability for Toxic Anionic Dye

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Inas A. Ahmed ◽  
Najlaa S. Al-Radadi ◽  
H. S. Hussein ◽  
Ahmed H. Ragab
Keyword(s):  
Crystal Size ◽  
Pore Radius ◽  
Morphological Properties ◽  
Anionic Dyes ◽  
Adsorption Ability ◽  
Waste Products ◽  
X Ray ◽  
Anionic Dye ◽  
Eriochrome Black T ◽  
Adsorption Desorption

In this work, a mesoporous nanocomposite composed of nanogibbsite (α-Al(OH)3) and nanosilica was prepared. Gibbsite nanoparticles (GNPs) with a crystal size of ≈38 nm were prepared from Al-dross industrial waste products in an acidic environment at 100°C. Nanosilica (NS) with a crystal size of ≈13 nm was prepared from sodium silicate using dilute hydrochloric acid. The deposition of nanosilica onto gibbsite particles was investigated. The mesoporous silica-gibbsite (NSG) nanocomposite was examined by evaluating its ability to adsorb the toxic anionic dye Eriochrome black T (EBT) from aqueous solution. The compositional and morphological properties of NSG nanocomposites were studied by means of the FTIR spectroscopy, X-ray fluorescence (XRF), XRD, SEM, and TEM techniques. The effect of dye concentration, pH, adsorbent dose, contact time, and temperature was investigated. The sorption models, the isotherms, and the thermodynamic parameters ΔHo, ΔGo, and ΔSo were evaluated. The N2 adsorption-desorption isotherms revealed that mixing the two prepared materials (NS and GNPs) to form the NSG nanocomposite resulted in good properties (a surface area of 62.34 m2·g−1, a pore radius of 22.717 nm, and a pore volume of 0.7081 cm3·g−1). The results show that the prepared NSG nanocomposite has a remarkable ability to adsorb toxic anionic dyes.

scholarly journals Ion Exchange of Benzoate in Ni-Al-Benzoate Layered Double Hydroxide by Amoxicillin

2019 ◽  
Vol 17 (1) ◽  
pp. 1043-1049
Author(s):  
Dian Windy Dwiasi ◽  
Mudasir Mudasir ◽  
Roto Roto
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Layered Double Hydroxide ◽  
Exchange Process ◽  
X Ray ◽  
Batch Technique ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Double Hydroxide ◽  
Benzoate Anion

AbstractThe Ni-Al-NO3 layered double hydroxide (LDH) compound has been intercalated with benzoate anion through an anion exchange process for amoxicillin drug adsorption. The purpose of this research is to synthesize Ni-Al-NO3, ion exchange with benzoate anion to form Ni-Al-Benzoate, and then applying it as an adsorbent of amoxicillin. The adsorption process was carried out using the batch technique. The materials synthesized in this study were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray ray diffraction (XRD), and Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA). The exchange of benzoate in Ni-Al-Benzoate LDH by amoxicillin was followed by UV-Vis spectrophotometry. The pH, LDH amount, and contact time are optimized. The adsorption of amoxicillin by Ni-Al-Benzoate is fit to the pseudo-second-order kinetics model, with an adsorption capacity of 40 mg/ g. The results showed that anion exchange was successfully carried out between benzoate anion and amoxicillin.

Optimization of ultrasonic-assisted copper ion removal from polluted water by a natural clinoptilolite nanostructure through a central composite design

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 339-347 ◽  
Author(s):  
Mohsen Sheydaei ◽  
Ali Balanejad Gasemsoltanlu ◽  
Asadollah Beiraghi
Keyword(s):  
Ftir Spectroscopy ◽  
Polluted Water ◽  
Sonication Time ◽  
X Ray ◽  
Ion Removal ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Natural Clinoptilolite ◽  
Adsorption Desorption ◽  
Central Composite

AbstractA natural clinoptilolite nanostructure (CNS) along with ultrasonic irradiation was used to remove Cu2+ ions from polluted water. In the first part of this work, natural clinoptilolite was converted to CNS by ball milling. The natural clinoptilolite and prepared CNS samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction, N2 adsorption/desorption and pH at the point of zero charge analyses. The SEM images showed the development of CNS from natural clinoptilolite by ball milling. The N2 adsorption/desorption and FTIR spectroscopy confirmed the greater specific surface area, pore volume and number of surface groups of the CNS compared to the natural clinoptilolite. In addition, the crystalline phase of the CNS was the same as the natural clinoptilolite. In the second part of this work, the ultrasonic-assisted sorption of Cu2+ ions from polluted water by CNS was investigated. These experiments were optimized with response surface methodology based on central composite designs. The effects of initial pH of solution, CNS dosage, sonication time and temperature on Cu2+ ion-removal efficiency were investigated. By using a CNS dosage of 500 mg L−1, an initial pH of 6, a sonication time of 12 min and a sonication temperature of 45°C as optimal conditions, 97% of Cu2+ ions were removed from contaminated water. The initial pH was the most effective variable. Ultrasonic-assisted sorption of Cu2+ was more effective than sorption alone, onto the CNS.

scholarly journals Characterization and Evaluation of Zeolite A/Fe3O4 Nanocomposite as a Potential Adsorbent for Removal of Organic Molecules from Wastewater

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Emmanuel Nyankson ◽  
Jonas Adjasoo ◽  
Johnson Kwame Efavi ◽  
Reuben Amedalor ◽  
Abu Yaya ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Isotherm Models ◽  
Adsorption Efficiency ◽  
Ferrous Chloride ◽  
X Ray ◽  
Intraparticle Diffusion Model ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Chloride Salts

In this work, zeolite (Z) and Z-Fe3O4 nanocomposite (Z-Fe3O4 NC) have been synthesized. The Fe3O4 nanoparticles were synthesized using the extract from maize leaves and ferric and ferrous chloride salts and encapsulated into the zeolite framework. The nanocomposite (Z-Fe3O4 NC) was characterized using X-ray diffractometer (XRD), Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The potential of Z-Fe3O4 NC as an adsorbent for removing methylene blue molecules (MB) from solution was examined using UV-Vis and kinetic and equilibrium isotherm models. The adsorption data fitted best with the pseudo-second-order model and Weber and Morris model, indicating that the adsorption process was chemisorption, while the Weber and Morris described the rate-controlling steps. The intraparticle diffusion model suggests that the adsorption processes were pore and surface diffusion controlled. The Langmuir isotherm model best describes the adsorption process indicating homogeneous monolayer coverage of MB molecules onto the surface of the Z-Fe3O4 NC. The maximum Langmuir adsorption capacity was 2.57 mg/g at 25°C. The maximum adsorption efficiency was 97.5%. After regeneration, the maximum adsorption efficiency achieved at a pH of 7 was 82.6%.

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