Ni-Fe layered double hydroxides catalized ozonation of synthetic wastewater containing Bisphenol A and municipal secondary effluent

Chemosphere ◽  
2019 ◽  
Vol 235 ◽  
pp. 143-152 ◽  
Author(s):  
Yuanxing Huang ◽  
Tingting Yang ◽  
Manli Liang ◽  
Yaowei Wang ◽  
Zhihua Xu ◽  
...  
Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4089
Author(s):  
Cristina Modrogan ◽  
Simona Cǎprǎrescu ◽  
Annette Madelene Dǎncilǎ ◽  
Oanamari Daniela Orbuleț ◽  
Eugeniu Vasile ◽  
...  

Magnesium–aluminum (Mg-Al) and magnesium–aluminum–nickel (Mg-Al-Ni) layered double hydroxides (LDHs) were synthesized by the co-precipitation method. The adsorption process of Mn2+ from synthetic wastewater was investigated. Formation of the layered double hydroxides and adsorption of Mn2+ on both Mg-Al and Mg-Ni-Al LDHs were observed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDX) analysis. XRD patterns for prepared LDHs presented sharp and symmetrical peaks. SEM studies revealed that Mg-Al LDH and Mg-Al-Ni LDH exhibit a non-porous structure. EDX analysis showed that the prepared LDHs present uniformly spread elements. The adsorption equilibrium on these LDHs was investigated at different experimental conditions such as: Shaking time, initial Mn2+ concentration, and temperatures (10 and 20 °C). The parameters were controlled and optimized to remove the Mn2+ from synthetic wastewater. Adsorption isotherms of Mn2+ were fitted by Langmuir and Freundlich models. The obtained results indicated that the isotherm data fitted better into the Freundlich model than the Langmuir model. Adsorption capacity of Mn2+ gradually increased with temperature. The Langmuir constant (KL) value of Mg-Al LDH (0.9529 ± 0.007 L/mg) was higher than Mg-Al-Ni LDH (0.1819 ± 0.004 L/mg), at 20 °C. The final adsorption capacity was higher for Mg-Al LDH (91.85 ± 0.087%) in comparison with Mg-Al-Ni LDH (35.97 ± 0.093%), at 20 °C. It was found that the adsorption kinetics is best described by the pseudo-second-order model. The results indicated that LDHs can be considered as a potential material for adsorption of other metallic ions from wastewater.


2013 ◽  
Vol 681 ◽  
pp. 21-25
Author(s):  
Yu Bing Pu ◽  
Jia Rui Wang ◽  
Hong Zheng ◽  
Peng Cai ◽  
Si Yuan Wu

A series of MgAlFe-CO3 layered double hydroxides (LDHs) were successfully prepared by co-precipitation method. With synthetic wastewater, the effect of doped iron on fluoride sorption by calcined MgAlFe-CO3 layered double hydroxides (CLDH) under different pH and contact time conditions was investigated. The sorption isotherm data were fitted well to Langmuir isotherm at 25 °C. The maximum sorption capacity of fluoride on CLDH increases first and then decreases with the increase of Fe/Al molar ratio and attains maximum of 71.94 mg/g when Fe/Al molar ratio is 1:2, although doped iron is unfavorable to the regeneration of original layered structure for CLDH after fluoride adsorption. No aluminium in the solution after fluoride adsorption was detected when Fe/Al molar ratio is equal to or larger than 1:2. The results indicate that CLDH with proper Fe/Al molar ratio is a promising candidate as an adsorbent material for fluoride removal from aqueous solutions.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1951 ◽  
Author(s):  
Fenglian Huang ◽  
Shiqiang Tian ◽  
Yan Qi ◽  
Erping Li ◽  
Liangliang Zhou ◽  
...  

(1) Background: Iron tetrasulfophthalocyanine with a large nonlinear optical coefficient, good stability, and high catalytic activity has aroused the attention of researchers in the field of photo-Fenton reaction. Further improvement of the visible light photo-Fenton catalytic activity under circumneutral pH conditions for their practical application is still of great importance. (2) Methods: In this paper, iron tetrasulfophthalocyanine (FePcS) and phosphomolybdic acid (PMA) cointercalated layered double hydroxides (LDH) were synthesized by the ion-exchange method. All samples were fully characterized by various techniques and the results showed that FePcS and PMA were successfully intercalated in layered double hydroxides and the resulted compound exhibited strong absorption in the visible light region. The cointercalation compound was tested as a heterogeneous catalyst for the visible light photo-Fenton degradation of bisphenol A (BPA) at circumneutral pH. (3) Results: The results showed that the degradation and total organic carbon removal efficiencies of bisphenol A were 100% and 69.2%, respectively. (4) Conclusions: The cyclic voltammetry and electrochemical impedance spectroscopy measurements demonstrated that the main contribution of PMA to the enhanced photo-Fenton activity of FePcS–PMA–LDH comes from the acceleration of electron transfer in the reaction system. Additionally, the possible reaction mechanism in the photo-Fenton system catalyzed by FePcS–PMA–LDH was also proposed.


2019 ◽  
Vol 552 ◽  
pp. 122-133 ◽  
Author(s):  
Pei Zhong ◽  
Qianqian Yu ◽  
Jiawen Zhao ◽  
Shuang Xu ◽  
Xinhong Qiu ◽  
...  

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  

<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>


2018 ◽  
Vol 69 (2) ◽  
pp. 321-323
Author(s):  
Georgeta Zegan ◽  
Elena Mihaela Carausu ◽  
Loredana Golovcencu ◽  
Alina Sodor Botezatu ◽  
Eduard Radu Cernei ◽  
...  

Anionic clay matrix acting as drug controlled release system have shown in last years a great potential for delivery of bioactive molecules and chemical therapeutics. This organic-inorganic nanohybrid system is high efficient offering an excellent protection of intercalated compounds from degradation. Compared to other nanoparticles used in medical area, anionic clays type layered double hydroxides have found to be biocompatible according to toxicological studies. Ampicillin containing MgAlLDHs and ZnAlLDH samples have been prepared following two routes: anion-exchange procedure and reconstruction from calcined layered double hydroxides. Solid samples have been characterized by FTIR and SEM-EDX highlighting the alteration of pristine LDHs structure when the antibiotic is introduced in the interlayer gallery.


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