scholarly journals Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 462 ◽  
Author(s):  
Karen Maria Dietmann ◽  
Tobias Linke ◽  
Miguel del Nogal Sánchez ◽  
José Luis Pérez Pavón ◽  
Vicente Rives
Keyword(s):  
Organic Solvents ◽  
Layered Double Hydroxides ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Oxidation Processes ◽  
Remediation Strategies ◽  
Chlorinated Organic ◽  
Hazardous Pollutants ◽  
Double Hydroxides

The contamination by chlorinated organic solvents is a worldwide problem as they can deeply penetrate aquifers, accumulating in the sub-surface as lenses of highly hazardous pollutants. In recent years, so called in situ oxidation processes have been developed to remediate chlorinated organic solvents from groundwater and soil by injecting solutions of oxidising agents such as permanganate or peroxydisulphate. We here present modified layered double hydroxides (LDHs) with intercalated oxidising agents that might serve as new reactants for these remediation strategies. LDHs might serve as support and stabiliser materials for selected oxidising agents during injection, as the uncontrolled reaction and consumption might be inhibited, and guarantee that the selected oxidants persist in the subsurface after injection. In this study, LDHs with hydrotalcite- and hydrocalumite-like structures intercalated with permanganate and peroxydisulphate anions were synthesised and their efficiency was tested in batch experiments using trichloroethene or 1,1,2-trichloroethane as the target contaminants. All samples were characterised using powder X-ray diffraction, thermal analysis coupled with mass spectrometry to directly analyse evolving gases, and Fourier-transform infrared spectroscopy. Additionally, particle size distribution measurements were carried out on the synthesised materials. Results of the batch experiments confirmed the hypothesis that oxidising agents keep their properties after intercalation. Permanganate intercalated LDHs proved to be most efficient at degrading trichloroethene while peroxydisulphate intercalated Ca,Al-LDHs were the most promising studied reactants degrading 1,1,2-trichloroethane. The detection of dichloroethene as well as the transformation of the studied reactants into new LDH phases confirmed the successful degradation of the target contaminant by oxidation processes generated from the intercalated oxidising agent.

scholarly journals Effect of Chain Length and Functional Group of Organic Anions on the Retention Ability of MgAl- Layered Double Hydroxides for Chlorinated Organic Solvents

2019 ◽  
Vol 3 (4) ◽  
pp. 89 ◽  
Author(s):  
Karen Maria Dietmann ◽  
Tobias Linke ◽  
Raquel Trujillano ◽  
Vicente Rives
Keyword(s):  
Chain Length ◽  
Organic Solvents ◽  
Layered Double Hydroxides ◽  
Functional Group ◽  
Interlayer Space ◽  
Organic Anions ◽  
Batch Experiments ◽  
Swelling Properties ◽  
Chlorinated Organic ◽  
Double Hydroxides

Nowadays, the contamination of groundwater and soils by chlorinated organic solvents is a severe and worldwide problem. Due to their swelling properties, Layered Double Hydroxides (LDHs) are potentially excellent compounds to retain chlorinated organic solvents from aquifers. By intercalating organic anions, the polarity of the interlayer space can be changed from hydrophilic to hydrophobic, enhancing the adsorption of chloro-organic molecules onto the alkyl chains of intercalated organic anions. In this study, organically modified LDHs were synthesized and their efficiency was tested in batch experiments with three different chlorinated organic solvents, namely trichloroethylene, 1,1,2-trichloroethane and trichloromethane (chloroform), to examine the influence of the chain length and the functional group of the intercalated organic anion upon the retention ability of a LDH due to different electronic interactions and different sizes of the interlayer space. All synthesized and used samples were characterized using powder X-ray diffraction, thermal analysis coupled with mass spectrometry and Fourier-transform infrared spectroscopy; freshly synthesized materials were additionally analyzed regarding their particle size distribution and specific surface area. Results of the batch experiments showed that only LDHs with intercalated long-chain organic anions could be efficient adsorbents for the removal of chlorinated organic solvents from contaminated water. A selective efficiency towards 1,1,2-trichloroethane and trichloromethane can be proposed for these reactants.

Probing the thermal decomposition process of layered double hydroxides through in situ 57Fe Mössbauer and in situ X-ray diffraction experiments

2006 ◽  
Vol 42 (2) ◽  
pp. 534-538 ◽  
Author(s):  
Daniel X. Gouveia ◽  
Odair P. Ferreira ◽  
Antonio G. Souza Filho ◽  
M. G. da Silva ◽  
J. A. C. de Paiva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Layered Double Hydroxides ◽  
Decomposition Process ◽  
X Ray Diffraction ◽  
Thermal Decomposition Process ◽  
X Ray ◽  
57Fe Mössbauer ◽  
Double Hydroxides

scholarly journals In situ synthesis of layered double hydroxides on γ-Al2O3 and its application in chromium(VI) removal

2017 ◽  
Vol 75 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
Shifeng Li ◽  
Fang Qi ◽  
Min Xiao ◽  
Hongtao Fan ◽  
Yanming Shen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxides ◽  
Adsorptive Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Chromium Vi ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxides

Mg-Al layered double hydroxides (LDHs) adsorbent was synthesized in situ on γ-Al2O3 for the removal of Cr(VI) from aqueous solution. The material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electronic microscopy and thermogravimetry and differential thermal analysis. Compared to the LDHs powder, the calcined LDHs sorbent prepared in situ on γ-Al2O3 had higher specific surface area and was easy to recover and reuse. The adsorptive capacity for removing Cr(VI) from aqueous solution was resulting from the memory effect of LDHs based on the XRD results. Both the pseudo-second-order kinetic model and the Langmuir model fit the experimental data well. Furthermore, the adsorbent exhibits excellent sorption–regeneration performances.

scholarly journals Interlayer intercalation and arrangement of 2-mercaptobenzothiazolate and 1,2,3-benzotriazolate anions in layered double hydroxides: In situ X-ray diffraction study

2016 ◽  
Vol 233 ◽  
pp. 158-165 ◽  
Author(s):  
Maria Serdechnova ◽  
Andrei N. Salak ◽  
Filipe S. Barbosa ◽  
Daniel E.L. Vieira ◽  
João Tedim ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Layered Double Hydroxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Hydroxides

Observation of a Collapsing Layer Structure in Mg/Al Layered Double Hydroxides with Interlayer Hydrogen Phosphate by High Temperature In Situ X-Ray Diffraction with Synchrotoron Radiation

2011 ◽  
Vol 700 ◽  
pp. 67-70
Author(s):  
Akihiro Shimamura ◽  
Linus Perander ◽  
Eiji Kanezaki ◽  
Mark Ian Jones ◽  
James B. Metson
Keyword(s):  
High Temperature ◽  
Thermal Behavior ◽  
Layered Double Hydroxides ◽  
Layer Structure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Hydrogen Phosphate ◽  
X Ray ◽  
Double Hydroxides

The collapsing layer structure of hydrogen phosphate intercalated Mg/Al-layered double hydroxides (LDH-HPO4) was investigated by high temperature in-situ X-ray diffraction with synchrotron radiation (in-situ XRD). The thermal behavior of the layer structure of LDH-HPO4 showed the same behavior in both in-situ and ex-situ XRD up until 109 °C as previously reported. The basal spacing of LDH-HPO4 continuously decreases above this temperature and finally the layer structure of LDH-HPO4 collapses. Another diffraction peak, d110, which gives a lattice constant a0, decreases at 62 °C, keeps constant to 120°C, increases up to 176°C and again keeps constant until the layer collapse. In this study, the different thermal behavior is observed between two reflections by in-situ XRD measurement, which explains the mechanism of the collapse of the layer structure in LDH-HPO4.

scholarly journals Structural analysis of defects in layered double hydroxides and related mixed oxides

2019 ◽  
Vol 62 (1-2) ◽  
pp. 39-54
Author(s):  
N.N. Leont’eva ◽  
V.A. Drozdov ◽  
O.B. Belskaya ◽  
S.V. Cherepanova
Keyword(s):  
Layered Double Hydroxides ◽  
Mixed Oxides ◽  
Simulation Method ◽  
X Ray Diffraction ◽  
Structural Mechanism ◽  
X Ray ◽  
Physicochemical Methods ◽  
The Difference ◽  
Double Hydroxides

This article provides an overview of the results of studying the defects in the structure of MgAl and NiAl layered double hydroxides and their thermal decomposition products up to 1000 °C, obtained over the last 10 years in the laboratory of analytical and physicochemical methods of research at the Institute of Hydrocarbons Processing of the SB RAS. The presented results were performed using the X-ray diffraction pattern simulation method for onedimensional (1D) disordered crystals. Changes in the type of structure defects are found depending on the calcination temperature, including in situ X-ray diffraction. A structural mechanism for the formation of a dehydrated phase at T=200 °C is proposed. New models of MgAl and NiAl oxide structures are presented. The structures of the phases included in the products of hydration of oxides are established. The difference in the behavior of oxides during hydration is explained.

Anion exchange in Zn–Al layered double hydroxides: In situ X-ray diffraction study

2010 ◽  
Vol 495 (1-3) ◽  
pp. 73-76 ◽  
Author(s):  
Andrei N. Salak ◽  
João Tedim ◽  
Alena I. Kuznetsova ◽  
Mikhail L. Zheludkevich ◽  
Mário G.S. Ferreira
Keyword(s):  
Diffraction Study ◽  
Anion Exchange ◽  
Layered Double Hydroxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Hydroxides
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