scholarly journals Boron Removal Using Li-Al-OH Layered Double Hydroxide Prepared by One-Step Mechanochemical Approach

Author(s):  
Jingjing Tian ◽  
Jun Qu ◽  
Lei Wan ◽  
Qiwu Zhang ◽  
Huimin Gao

In this study, Li-Al-OH layered double hydroxide (LDH), which was prepared by solvent-free one-step mechanochemical reaction of LiOH and Al(OH)3, was applied to remove boron from aqueous solution. Dry-grinding for 3 h at a rotational speed of 500 rpm, Li/Al molar 1/2 was the optimum condition to prepare highly crystalline of Li-Al LDH phase with no evident impure phases. Two milling products with Li/Al molar ratio at 1/2 and 2/2 were evaluated for boron adsorption. The results confirmed that Li/Al molar ratio 2/2 sample showed high boron adsorption capacity due to the physical adsorption of Li-Al-OH LDH and chemical synergism of phase gel Al(OH)3. The adsorption isotherms, described by the Langmuir model, indicated maximum monolayer boron uptake capacity 45.45 mg/g, implying competitive adsorption capacity of the material in our experiment.

2020 ◽  
Vol 9 (2) ◽  
pp. 383-391

A MgCr-based layered double hydroxide (LDH) was synthesized by a coprecipitation method, followed by an intercalation process using an oxalic anion. The materials were characterized using X-ray diffraction analysis, FT-IR spectroscopy, and pH pzc measurement. The materials were then applied as adsorbents for removal of methylene blue (MB) and rhodamine B (RhB) from aqueous solution. Pristine Mg/Cr LDH exhibited RhB adsorption capacity of 32.154 mg g⁻1, whereas the use of intercalated Mg/Cr LDH caused an increase in the capacity (139.526 mg g⁻1). Kinetic studies indicated that the dye adsorption using both LDHs followed a pseudo-second-order kinetic model; the K2 values of pristine and modified Mg/Cr LDH for RhB and MB were 6.970, 0.001, 0.426, and 2.056 g mg⁻1 min⁻1, respectively. The thermodynamic study identified that the adsorption of both dyes onto the LDHs was a spontaneous process and can be classified as physical adsorption with adsorption energies of <40 kJ/mol. Moreover, the desorption and regeneration experiments indicated the high economic feasibility and reusability of the LDHs. By using HCl as the optimal solvent, the LDHs could desorb as much as 98% of the dye and could be used as adsorbents with high adsorption capacity over three cycles.


2020 ◽  
Vol 9 (1) ◽  
pp. 85-94

A MgCr-based layered double hydroxide (LDH) was synthesized by a coprecipitation method, followed by an intercalation process using an oxalic anion. The materials were characterized using X-ray diffraction analysis, FT-IR spectroscopy, and pH pzc measurement. The materials were then applied as adsorbents for removal of methylene blue (MB) and rhodamine B (RhB) from aqueous solution. Pristine Mg/Cr LDH exhibited RhB adsorption capacity of 32.154 mg g⁻1, whereas the use of intercalated Mg/Cr LDH caused an increase in the capacity (139.526 mg g⁻1). Kinetic studies indicated that the dye adsorption using both LDHs followed a pseudo-second-order kinetic model; the K2 values of pristine and modified Mg/Cr LDH for RhB and MB were 6.970, 0.001, 0.426, and 2.056 g mg⁻1 min⁻1, respectively. The thermodynamic study identified that the adsorption of both dyes onto the LDHs was a spontaneous process and can be classified as physical adsorption with adsorption energies of <40 kJ/mol. Moreover, the desorption and regeneration experiments indicated the high economic feasibility and reusability of the LDHs. By using HCl as the optimal solvent, the LDHs could desorb as much as 98% of the dye and could be used as adsorbents with high adsorption capacity over three cycles.


2021 ◽  
Vol 23 (2) ◽  
pp. 103
Author(s):  
A. Lesbani ◽  
M.F. Azmi ◽  
N.R. Palapa ◽  
T. Taher ◽  
R. Andreas ◽  
...  

Layered double hydroxide (LDH) Ni/Cr intercalated [α-SiW12O40]4- has been prepared using the coprecipitation method. Materials were characterized by X-ray, FTIR, BET, and pHpzc analyses. Material Ni/Cr-[α-SiW12O40] LDHs exhibited a high surface area 98.986 m2 g-1 from 11.030 m2 g-1 for Ni/Cr LDH where the interlayer space was an increase from 7.99 to 10.87 Å with indicated that high crystallinity. Ni/Cr-[α-SiW12O40] LDHs showed higher adsorption capacity for iron(II) is up to 250 mg g-1. Adsorption of iron(II) on LDHs has an endothermic process and classify as physical adsorption.


2011 ◽  
Vol 148-149 ◽  
pp. 1276-1279 ◽  
Author(s):  
Li Fang Zhang

In this study, the adsorption of C. I. Reactive Red 2 from aqueous solution on Ni-Al layered double hydroxide (LDH) was investigated in a batch system. The effect of Ni-Al molar ratio, pH, temperature and initial dye concentration on adsorption of the dye was carried out. The results showed that Ni-Al layered double hydroxide had higher capacity of removal of the dye. Ni-Al LDH with Ni-Al molar ratio of 3 exhibited the maximum dye removal at pH 4.0. Adsorption capacity of dye increased with increasing temperature or initial dye concentration. It was found that the adsorption equilibrium data followed the Langmuir adsorption model. The maximum adsorption capacity obtained from the Langmuir equation at temperature of 30°C was 333.3mg/g (R2=0.991) for the dye.


2011 ◽  
Vol 287-290 ◽  
pp. 390-393
Author(s):  
Li Fang Zhang ◽  
Ying Ying Chen

The adsorption of C. I. Reactive Red 2 from aqueous solution on Zn-Al calcined layered double hydroxide (CLDH) was investigated. Experiments were carried out as a function of Zn-Al molar ratio, contact time, pH, temperature and initial dye concentration. The results showed that Zn-Al calcined layered double hydroxide had higher capacity of removal of the dye. Zn-Al CLDH with Zn-Al molar ratio of 3 and with pH range of 4.0-8.0 was found to be optimal for dye removal. Adsorption capacity of dye decreased with increasing temperature and increased with increasing initial dye concentration. It was found that the adsorption equilibrium data followed the Langmuir adsorption model. The maximum adsorption capacity obtained from the Langmuir equation at temperature of 30°C was 116.28mg/g (R2=0.9992) for the dye.


2021 ◽  
Author(s):  
Zihao Liu ◽  
Shifeng Li ◽  
Fangfang Wang ◽  
Mingxia Li ◽  
Yonghong Ni

FeNi-layered double hydroxide (LDH) is thought to be an excellent electrocatalyst for oxygen evolution reaction (OER), but it always shows extremely poor electrocatalytic activity toward hydrogen evolution reaction (HER) in...


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.


ChemInform ◽  
2004 ◽  
Vol 35 (51) ◽  
Author(s):  
Alexey V. Lukashin ◽  
Andrei A. Eliseev ◽  
Natalya G. Zhuravleva ◽  
Alexey A. Vertegel ◽  
Yuri D. Tretyakov ◽  
...  

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