scholarly journals Removal of Lead from Aqueous Solution by Adsorption using Magnesium Aluminium Hydrogenphosphate Layered Double Hydroxides

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Zaini Hamzah ◽  
Mohd Najif Ab Rahman ◽  
Yamin Yasin ◽  
Siti Mariam Sumari ◽  
Ahmad Saat
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Layered double hydroxide with molar ratio of 4 (MAN 4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was then later going through ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP 4). The solid produced were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of lead solution by MAHP 4 was carried out using batch experiment by mixing the lead solution and the solid of layered double hydroxide. The effects of various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for lead removal was found to be at pH of 5 and the optimum time of lead removal was found at 2 hours. The isotherm data was analysed using Langmuir and the correlation coefficient of 0.998 was obtained. The maximum adsorption capacity, Qo (mg/g) of 500 mg/g was also recorded from the Langmuir isotherm. The remaining lead solution was determined by using EDXRF (Energy Dispersive X-Ray Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP 4 was an interesting adsorbent for removing lead from aqueous solution.

scholarly journals Corrosion Resistance of Electrochemically Synthesized Modified Zaccagnaite LDH-Type Films on Steel Substrates

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7389
Author(s):  
Michael Kahl ◽  
Teresa D. Golden
Keyword(s):  
Corrosion Resistance ◽  
Layered Double Hydroxide ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Steel Substrates ◽  
Deposited Films

Modified zaccagnaite layered double hydroxide (LDH) type films were synthesized on steel substrates by pulsed electrochemical deposition from aqueous solutions. The resulting films were characterized by X-ray diffraction, scanning electron microscopy/X-ray dispersive spectroscopy, and Fourier transform infrared spectroscopy. Structural characterization indicated a pure layered double hydroxide phase; however, elemental analysis revealed that the surface of the films contained Zn:Al ratios outside the typical ranges of layered double hydroxides. Layer thickness for the deposited films ranged from approximately 0.4 to 3.0 μm. The corrosion resistance of the film was determined using potentiodynamic polarization experiments in 3.5 wt.% NaCl solution. The corrosion current density for the coatings was reduced by 82% and the corrosion potential was shifted 126 mV more positive when 5 layers of modified LDH coatings were deposited onto the steel substrates. A mechanism was proposed for the corroding reactions at the coating.

scholarly journals Zn-Al Layered Double Hydroxide Thin Film Fabricated by the Sputtering Method and Aqueous Solution Treatment

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 669
Author(s):  
Jaehwan Shin ◽  
Kyunghwan Kim ◽  
Jeongsoo Hong
Keyword(s):  
Aqueous Solution ◽  
Solution Treatment ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Experiment Data ◽  
X Ray ◽  
Facing Target Sputtering ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Synthesis Experiment

Zn-Al layered double hydroxides (LDHs) were synthesized herein via a simple process. First, Al-doped ZnO film was deposited onto a glass substrate using the facing target sputtering system. Successful synthesis of the Zn–Al LDH was achieved via a treatment process using an aqueous solution which contains NO3− anions. X-ray diffraction analysis confirmed that it was consistent with the previous Zn–Al LDH synthesis experiment data, and the calculated d-value was 9.1 Å. Scanning electron microscopy observations revealed that the as-synthesized sample had a plate-like structure.

scholarly journals Fe(III) Complexed Polydopamine Modified Mg/Al Layered Double Hydroxide Enhances The Removal of Cr(VI) From Aqueous Solutions

2021 ◽  
Author(s):  
Changcheng Chen ◽  
Mina Luo ◽  
Fu Chen ◽  
Chao Huang ◽  
Chunmei Zhu ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Removal Capacity ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Influence Of Ph

Abstract Herein, we report the preparation of Fe(III) complexed polydopamine modified Mg/Al layered double hydroxides composite material (LDHs@PDA-Fe(III)) and its application to the removal of Cr(VI) in aqueous solution. LDHs@PDA-Fe(III) was characterized and analyzed by field-emission scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transformed infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron (XPS). The adsorption performance was studied through a series of adsorption experiments. Under the influence of pH, time, temperature, concentration, the maximum adsorption capacity obtained in the experiment is 683.4 mg/g. In addition, after 5 adsorption cycles, LDHs@PDA-Fe(III) still shows excellent adsorption capacity and stability. Combining adsorption experiments and characterization analysis, it is inferred that the adsorption of Cr(VI) by LDHs@PDA-Fe(III) is the result of the synergistic effect of multiple adsorption mechanisms. Therefore, the efficient removal capacity and excellent stability make LDHs@PDA-Fe(III) an ideal adsorbent for removing Cr(VI) from aqueous solutions.

scholarly journals Removal of methylene blue from aqueous solution using Mg-Fe, Zn-Fe, Mn-Fe layered double hydroxide

2020 ◽  
Vol 81 (12) ◽  
pp. 2522-2532
Author(s):  
Zhongliang Shi ◽  
Yanmei Wang ◽  
Shuyu Sun ◽  
Cheng Zhang ◽  
Haibo Wang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Langmuir Adsorption ◽  
Molar Ratios ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Abstract Layered double hydroxides (LDH) with highly flexible and adjustable chemical composition and physical properties have attracted tremendous attention in recent years. A series of LDH with different M (Mg, Zn, Mn)-Fe molar ratios were synthesized by the double titration co-precipitation method. The effect of the factors, including M (Mg, Zn, Mn) : Fe molar ratio, pH, and M-Fe LDH dosage, on the ability of the prepared M-Fe LDH to remove cationic methylene blue (MB) dye from aqueous solution were investigated. Results indicated that the removal efficiency of MB (10 mg/L) was the best at the M (Mg, Zn, Mn): Fe molar ratio of 3:1 by using 2.0 g/L of M-Fe LDH at pH 6.0 under 298.15 K. Mg-Fe LDH had the highest removal performance (71.94 mg/g at 298.15 K) for MB compared to those of the Zn-Fe and Mn-Fe LDH. Zn-Fe LDH with the smallest activation energy resulted in the fastest adsorption rate of MB. The pseudo-second-order model and Langmuir adsorption isotherm were also successfully applied to fit the theory of M-Fe LDH for removal of MB.

scholarly journals Synthesis and Characterization of CuFe2O4 Nanoparticles Modified with Polythiophene: Applications to Mercuric Ions Removal

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 586 ◽  
Author(s):  
Ayman H. Kamel ◽  
Amr A. Hassan ◽  
Abd El-Galil E. Amr ◽  
Hadeel H. El-Shalakany ◽  
Mohamed A. Al-Omar
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Transmission Electron ◽  
Enhanced Adsorption ◽  
Co Precipitation ◽  
Adsorption Desorption

In this research, CuFe2O4 nanoparticles were synthesized by co-precipitation methods and modified by coating with thiophene for removal of Hg(II) ions from aqueous solution. CuFe2O4 nanoparticles, with and without thiophene, were characterized by x-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and Brunauer–Emmett–Teller (BET). Contact time, adsorbent dose, solution pH, adsorption kinetics, adsorption isotherm and recyclability were studied. The maximum adsorption capacity towards Hg2+ ions was 7.53 and 208.77 mg/g for CuFe2O4 and CuFe2O4@Polythiophene composite, respectively. Modification of CuFe2O4 nanoparticles with thiophene revealed an enhanced adsorption towards Hg2+ removal more than CuFe2O4 nanoparticles. The promising adsorption performance of Hg2+ ions by CuFe2O4@Polythiophene composite generates from soft acid–soft base strong interaction between sulfur group of thiophene and Hg(II) ions. Furthermore, CuFe2O4@Polythiophene composite has both high stability and reusability due to its removal efficiency, has no significant decrease after five adsorption–desorption cycles and can be easily removed from aqueous solution by external magnetic field after adsorption experiments took place. Therefore, CuFe2O4@Polythiophene composite is applicable for removal Hg(II) ions from aqueous solution and may be suitable for removal other heavy metals.

scholarly journals Preparation and characterization of iron-copper binary oxide and its effective removal of antimony(III) from aqueous solution

2016 ◽  
Vol 74 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Yongchao Li ◽  
Bing Geng ◽  
Xiaoxian Hu ◽  
Bozhi Ren ◽  
Andrew S. Hursthouse
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Binary Oxide ◽  
Molar Ratio ◽  
Precipitation Process ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
X Ray ◽  
Freundlich Adsorption Isotherm ◽  
Co Precipitation

An Fe-Cu binary oxide was fabricated through a simple co-precipitation process, and was used to remove Sb(III) from aqueous solution. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and N2 adsorption–desorption measurements demonstrated that the Fe-Cu binary oxide consisted of poorly ordered ferrihydrite and CuO, and its specific surface area was higher than both iron oxide and copper oxide. A comparative test indicated that Fe/Cu molar ratio of prepared binary oxide greatly influenced Sb(III) removal and the optimum Fe/Cu molar ratio was about 3/1. Moreover, a maximum adsorption capacity of 209.23 mg Sb(III)/g Fe-Cu binary oxide at pH 5.0 was obtained. The removal of Sb(III) by Fe-Cu binary oxide followed the Freundlich adsorption isotherm and the pseudo-second-order kinetics in the batch study. The removal of Sb(III) was not sensitive to solution pH. In addition, the release of Fe and Cu ions to water was very low when the pH was greater than 6.0. X-ray photoelectron spectroscopy analysis confirmed that the Sb(III) adsorbed on the surface was not oxidized to Sb(V).

Removal of C. I. Reactive Red 2 from Aqueous Solution by Ni-Al Layered Double Hydroxide

2011 ◽  
Vol 148-149 ◽  
pp. 1276-1279 ◽  
Author(s):  
Li Fang Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data ◽  
Double Hydroxide ◽  
Reactive Red 2

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.

scholarly journals Removal of Iron(II) Using Intercalated Ca/Al Layered Double Hydroxides with [α-SiW12O40]4-

2019 ◽  
Vol 14 (2) ◽  
pp. 260 ◽  
Author(s):  
Tarmizi Taher ◽  
Mikha Meilinda Christina ◽  
Muhammad Said ◽  
Nurlisa Hidayati ◽  
Ferlinahayati Ferlinahayati ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Layer Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Synthesized Materials

Ca/Al layered double hydroxide (LDH) was successfully synthesized by co-precipitation method at pH 11 under room temperature condition then followed by calcination at 800 oC. The synthesized Ca/Al LDH was further intercalated with Keggin ion [α-SiW12O40]4- in order to prepare the intercalated form of Ca/Al LDH. The synthesized materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) and used as an adsorbent for iron(II) removal from the aqueous medium. The adsorption performance was investigated by studying the kinetics and thermodynamic properties of the adsorption process. The results showed that pristine Ca/Al LDH exhibited diffraction peak at 2θ about 20o which corresponds to the layer structure of the LDH material. For the intercalated Ca/Al LDH, the diffraction observed at 2θ around 30-40o indicated that the [α-SiW12O40]4- was successfully intercalated into the interlayer space of Ca/Al LDH. Furthermore, the intercalated Ca/Al LDH showed higher adsorption capacity toward iron(II) than the pristine form of Ca/Al LDH. Copyright © 2019 BCREC Group. All rights reserved 

scholarly journals Removal of indigo carmine and green bezanyl-F2B from water using calcined and uncalcined Zn/Al + Fe layered double hydroxide

2016 ◽  
Vol 7 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Hassiba Bessaha ◽  
Mohamed Bouraada ◽  
Louis Charles Deménorval
Keyword(s):  
Layered Double Hydroxide ◽  
Indigo Carmine ◽  
Standard Free Energy ◽  
Sorption Process ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Acid Dyes ◽  
Batch Mode ◽  
Co Precipitation ◽  
Double Hydroxide

Layered double hydroxide Zn/(Al + Fe) with a molar ratio of 3:(0.85 + 0.15), designated as ZAF-HT, was synthetized by co-precipitation. Its calcined product CZAF was obtained by heat treatment of ZAF-HT at 500°C. The calcined and uncalcined materials were used to remove the acid dyes indigo carmine (IC) and green bezanyl-F2B (F2B) from water in batch mode. The synthetized materials were characterized by X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis, Fourier transform infra-red spectroscopy and thermogravimetric/differential thermal analysis. The sorption kinetic data fitted a pseudo-second-order model. The adsorbed amounts of the calcined material were much larger than ZAF-HT. The maximum adsorption capacity of CZAF was found to be 617.3 mg g−1 for IC and 1,501.4 mg g−1 for F2B. The isotherms showed that the removal of IC and F2B by ZAF-HT and CZAF could be described by a Langmuir model. The thermodynamic parameters were also calculated. The negative values of standard free energy ΔG° indicate the spontaneity of sorption process. The reuse of CZAF was studied for both dyes and the calcined material showed a good stability for four thermal cycles.

Adsorption of Dye from Aqueous Solution by Zn-Al Calcined Layered Double Hydroxide

2011 ◽  
Vol 287-290 ◽  
pp. 390-393
Author(s):  
Li Fang Zhang ◽  
Ying Ying Chen
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Layered Double Hydroxide ◽  
Molar Ratio ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Equilibrium Data ◽  
Calcined Layered Double Hydroxide ◽  
Ph Range ◽  
Double Hydroxide

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.

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