Influence of Synthesis Temperature on Phosphate Adsorption by Zn-Al Layered Double Hydroxides in Excess Sludge Liquor

2011 ◽  
Vol 19 (3) ◽  
pp. 391-396 ◽  
Author(s):  
Xiang CHENG ◽  
Jiexu YE ◽  
Dezhi SUN ◽  
Aiyan CHEN
Keyword(s):  
Layered Double Hydroxides ◽  
Synthesis Temperature ◽  
Phosphate Adsorption ◽  
Excess Sludge ◽  
Double Hydroxides

scholarly journals Evaluation of Mg/Al Layered Double Hydroxides as Adsorbent Material for Adsorptive Removal of Congo Red (Acid Red 28) Azodye from Aqueous Solution

2020 ◽  
Vol 32 (9) ◽  
pp. 2381-2388
Author(s):  
LAM VAN TAN ◽  
HONG THAM NGUYEN THI ◽  
TO UYEN DAO THI ◽  
VAN THUAN TRAN
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxides ◽  
Congo Red ◽  
Organic Dyes ◽  
Synthesis Temperature ◽  
Inorganic Layer ◽  
Adsorptive Removal ◽  
Ft Ir ◽  
Ir Analysis ◽  
Double Hydroxides

The use of inorganic layer compounds as adsorbents for organic dyes in water treatment is of increasing interest. In this study, an attempt is made for the synthesis of Mg/Al LDHs by the hydrothermal method. The synthesis temperature was found to significantly affect to the structure of layered double hydroxides (LDHs), as pointed out by FT-IR analysis. In addition, an adsorption capacity of the synthesized LDHs against Congo red in aqueous solutions was investigated and also compared the adsorption results with other dyes such as methylene blue and methyl orange.

Phosphate Adsorption Site on Zirconium Ion Modified MgAl-layered Double Hydroxides

2009 ◽  
Vol 52 (6-7) ◽  
pp. 714-723 ◽  
Author(s):  
Hiroya Miyauchi ◽  
Takashi Yamamoto ◽  
Ramesh Chitrakar ◽  
Yoji Makita ◽  
Zhengming Wang ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Adsorption Site ◽  
Phosphate Adsorption ◽  
Double Hydroxides

scholarly journals Phosphate adsorption from sewage sludge filtrate using zinc–aluminum layered double hydroxides

2009 ◽  
Vol 169 (1-3) ◽  
pp. 958-964 ◽  
Author(s):  
Xiang Cheng ◽  
Xinrui Huang ◽  
Xingzu Wang ◽  
Bingqing Zhao ◽  
Aiyan Chen ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Layered Double Hydroxides ◽  
Phosphate Adsorption ◽  
Double Hydroxides

Insights into phosphate adsorption behavior on structurally modified ZnAl layered double hydroxides

2018 ◽  
Vol 165 ◽  
pp. 234-246 ◽  
Author(s):  
E.M. Seftel ◽  
R.G. Ciocarlan ◽  
B. Michielsen ◽  
V. Meynen ◽  
S. Mullens ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Adsorption Behavior ◽  
Phosphate Adsorption ◽  
Double Hydroxides

scholarly journals Synthesis of layered double hydroxides with nitrate and its adsorption properties of phosphate

2020 ◽  
Author(s):  
Jiangpo Zhang ◽  
Qi Xia ◽  
Xiaofeng Hong ◽  
Jianjun Chen ◽  
Daijun Liu
Keyword(s):  
Electron Microscopy ◽  
Layered Double Hydroxides ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Phosphate Adsorption ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Co Precipitation ◽  
Double Hydroxides

Abstract In the present study, different ratios of layered double hydroxides (LDHs) were synthesized via co-precipitation method. The synthesized LDHs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nitrogen adsorption-desorption analysis, point of zero charges (pHpzc), scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM). Phosphate adsorption performances were estimated by batch adsorption experiments; desorption hysteresis and adsorption mechanism were also investigated. The XRD, SEM and TEM results confirmed the multilayer structure of the synthesized LDHs. The pseudo-second-order kinetic model and the Freundlich model describe the adsorption behavior of LDHs best. The maximum adsorption capacity is 185.86 mg-KH2PO4/g for Mg2Al-NO3 LDH. When the dosage of LDHs was greater than 2 g/L, the phosphorus content in the solution decreased from 30 mg-P/L to 0.077 mg-P/L after adsorption by Mg2Al-NO3 LDH. All the results reveal that Mg2Al-NO3 LDH is a potential adsorbent for removing phosphate from aqueous solution.

scholarly journals Phosphorus desorption and recovery from aqueous solution using amorphous zirconium hydroxide/MgFe layered double hydroxides composite

2021 ◽  
Vol 926 (1) ◽  
pp. 012107
Author(s):  
A Nuryadin ◽  
T Imai
Keyword(s):  
Layered Double Hydroxides ◽  
Xrd Analysis ◽  
Zirconium Hydroxide ◽  
Phosphate Removal ◽  
Phosphorus Recovery ◽  
Molar Ratio ◽  
Phosphate Adsorption ◽  
Composite Surface ◽  
Double Hydroxides ◽  
Phosphate Desorption

Abstract Global phosphorus scarcity implies the importance of phosphorus recovery. Desorption is an essential process in phosphate removal by adsorption technique by enabling two crucial aspects: the reusability of adsorbent and the recovery of phosphorus. In this study, phosphate desorption by NaOH for composite reusability and phosphorus recovery by CaCl2 were investigated. Based on the cost analysis, the uncalcined amorphous zirconium hydroxide/MgFe layered double hydroxides composite (am-Zr/MgFe-LDH) with Zr to Fe molar ratio of 1.5 was effective in reducing cost for phosphate adsorption compared to amorphous zirconium hydroxide (am-Zr) and MgFe layered double hydroxide (LDH). The XRD analysis indicated that phosphate desorption was preferably performed by stripping adsorbed phosphate on the composite surface using NaOH solution. The reuse of 2 N NaOH for composite regeneration could effectively maintain a higher adsorption ability (86%) than 1 N NaOH, and additionally, could be considered as an economic regeneration agent. The composite was chemically stable in maintaining its structure during eight adsorption-desorption cycles. The mechanisms involved during phosphate desorption by NaOH were mainly ligand exchange and electrostatic repulsion. The phosphorus recovery showed that the optimum recovery (~95%) was obtained by adding CaCl2 at pH 13 and calcium to phosphorus molar ratio of 3.5.

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

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