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.

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.

Layered double hydroxide (LDH)-coated attapulgite for phosphate removal from aqueous solution

2011 ◽  
Vol 64 (11) ◽  
pp. 2192-2198 ◽  
Author(s):  
Gan Fang-qun ◽  
Zhou Jian-min ◽  
Wang Huo-yan ◽  
Zhao Hong-ting
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Tap Water ◽  
Packed Bed ◽  
Phosphate Removal ◽  
Maximum Adsorption Capacity ◽  
Batch Mode ◽  
Packed Bed Column ◽  
Competing Anions ◽  
Double Hydroxide

In this study, a composite adsorbent, layered double hydroxide (LDH)-coated attapulgite (LDH-AP), was synthesized and characterized. Its potential application for LDH stabilizer and phosphate (P) removal from aqueous solution was evaluated using the batch mode and continuous mode in a packed bed column. The batch experiments revealed that the data of P adsorption onto LDH-AP could be well described by the Freundlich equation, and the maximum adsorption capacity was estimated to be 6.9 mg/g. The column experiments were conducted in the tap water and the results indicated that the competing anions could slightly decrease phosphate removal. The saturated column was regenerated by 0.2 mol/L of NaOH and the regenerated column was examined for its reuse in phosphate removal. The results of this study suggested that attapulgite could be used as an applicable stabilizer of LDH and LDH-AP could be potentially used as a promising filtration medium for phosphate removal.

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 Adsorption and Reduction of Aqueous Cr by FeS-Modified Fe-Al Layered Double Hydroxide

2021 ◽  
Vol 14 (1) ◽  
pp. 21
Author(s):  
Shuangshuang Zhang ◽  
Wenhui Zhang ◽  
Yazhen Wan
Keyword(s):  
Layered Double Hydroxide ◽  
Removal Efficiency ◽  
Langmuir Adsorption Isotherm ◽  
Maximum Adsorption Capacity ◽  
Efficient Removal ◽  
Reaction Conditions ◽  
Langmuir Adsorption ◽  
Ultrasonic Assisted ◽  
Co Precipitation ◽  
Double Hydroxide

To remedy the widespread chromium (Cr) pollution in the environment, this study mainly used the ultrasonic-assisted co-precipitation and precipitation methods to prepare FeS-modified Fe-Al-layered double hydroxide (FeS/LDH) composite material. The experimental results showed that FeS/LDH has higher removal efficiency of Cr in aqueous solution and stronger anti-interference ability than unmodified LDH. Under the same reaction conditions, the removal efficiency of total Cr(Cr(T)) using LDH was 34.85%, and the removal efficiency of Cr(VI) was 46.76%. For FeS/LDH, the removal efficiency of Cr(T) and Cr(VI) reached 99.57% and 100%, respectively. The restoration of Cr(T) and Cr(VI) by FeS/LDH satisfied the Langmuir adsorption isotherm. The maximum adsorption capacity of Cr(T) and Cr(VI) achieved 102.9 mg/g and 147.7 mg/g. The efficient removal of Cr by FeS/LDH was mainly based on the triple synergistic effect of anion exchange between Cr(VI) and interlayer anions, redox of Cr(VI) with Fe2+ and S2−, and co-precipitation of Fe3+ and Cr3+.

Adsorption Properties of Dye onto Mg/Al-CO3 Layered Double Hydroxide

2012 ◽  
Vol 455-456 ◽  
pp. 677-682
Author(s):  
Li Fang Zhang ◽  
De Zhou Wei
Keyword(s):  
Layered Double Hydroxide ◽  
Dye Removal ◽  
Adsorption Equilibrium ◽  
Freundlich Isotherm ◽  
Molar Ratio ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Initial Ph ◽  
Double Hydroxide

Adsorption of reactive red on Mg/Al-CO3 layered double hydroxide in a batch stirred system was investigated. Experiments were carried out as function of Mg/Al molar ratio, contact time, initial pH, adsorbent amount and temperature. It was found that the maximum dye removal was at Mg/Al molar ratio of 3. Solution pH ranging from 2-8 had little effect on adsorption rate. Dye removal decreased with increased temperature in studied temperature range. The Langmuir and Freundlich isotherm models were used for modeling the adsorption equilibrium. The adsorption equilibrium data could well interpreted by the Langmuir models with maximum adsorption capacity of 131.58 mg/g (R2=0.9986). The results indicate the possible dye removal from water by using Mg/Al-CO3 layered double hydroxide.

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.

scholarly journals Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana, and Feldspar: Batch experiments

2011 ◽  
Vol 17 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Aiman Al-Rawajfeh ◽  
Khaldoon Al-Whoosh ◽  
Dwairi Al ◽  
Ahmad Al-Maaberah ◽  
Amer Tarawneh
Keyword(s):  
Layered Double Hydroxide ◽  
Metal Ion ◽  
Raw Materials ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Considerable Potential ◽  
Ion Concentrations ◽  
Pre Treatment ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, composites of layered double hydroxide (LDH) with three Jordanian natural raw materials; Tripoli (T), Pozzolana (P) and Feldspar (F) were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ?Go were negative and within 21 to 26 KJ/mol, while the values of ?Ho and ?So were positive and within the range of 0.1 to 25 KJ/mol. The values of ?H?, ?S?, and ?G? indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

An elegant synthesis of chitosan grafted hydrotalcite nano-bio composite material and its effective catalysis for solvent-free synthesis of jasminaldehyde

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94562-94570 ◽  
Author(s):  
Jacky H. Adwani ◽  
Noor-ul H. Khan ◽  
Ram S. Shukla
Keyword(s):  
Composite Material ◽  
Layered Double Hydroxide ◽  
Solvent Free ◽  
Precipitation Method ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Solvent Free Synthesis

A novel nano-bio composite of chitosan and a layered double hydroxide elegantly synthesized by a co-precipitation method had effectively and selectively catalysed the jasminaldehyde synthesis.

Stabilization of Dicalcium Silicate-Zn Composite Approaching Layered Double Hydroxide Structure for Bioactive Cement Applications

2022 ◽  
Author(s):  
Hind Agourrame ◽  
Amine Belafhaili ◽  
Nisrine El Fami ◽  
Nacer Khachani ◽  
Mohamed Alami Talbi ◽  
...  
Keyword(s):  
Acid Solution ◽  
Layered Double Hydroxide ◽  
S Phase ◽  
Dicalcium Silicate ◽  
Metal Salts ◽  
Basic Solution ◽  
Silicate Phase ◽  
Edax Analysis ◽  
Co Precipitation ◽  
Double Hydroxide

Layered Double Hydroxide (LDH) is ionic clay that is characterized by the union of metal cations and OH- hydroxides. LDH composites exhibit considerably high releasing and recharging capacity and have applications as bioactive cements. They can be prepared by direct co-precipitation of metal salts at controlled pH. The preparation is carried out from an acid solution of Zn (NO3)2.6H2O, Al (NO3)3.9H2O and a basic solution of Na2CO3 and NaOH, with a Zn/Al ratio = 3, the pH is stabilized between 9 and 9.5 at a constant temperature of 45°C. The objective of this study is to incorporate Zinc and Aluminum elements at different percentages in dicalcium silicate phase to produce C2S phase incorporating LDH composite. The characterizations of the developed phases by XRD and SEM indicate the formation of stoichiometric LDH phases Zn6Al2(OH)16CO3.4H2O and non-stoichiometric Zn0.61Al0.39 (OH)2(CO3)0.195.xH2O, the incorporation of Zn in the belitic C2S phase and not Al. The obtained micrographs by SEM(EDAX) analysis show new morphology of the stabilized composite.

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