Treatment of simulated liquid radioactive waste containing cobalt by in-situ co-precipitation of Zn/Al layered double hydroxides

2019 ◽  
Vol 319 (3) ◽  
pp. 847-854 ◽  
Author(s):  
Guangtuan Huang ◽  
Lifeng Shao ◽  
Xiaohong He ◽  
Li Jiang
Keyword(s):  
Radioactive Waste ◽  
Layered Double Hydroxides ◽  
Liquid Radioactive Waste ◽  
Co Precipitation ◽  
Double Hydroxides

scholarly journals Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

2020 ◽  
Vol 4 (3) ◽  
pp. 53
Author(s):  
Karen Maria Dietmann ◽  
Tobias Linke ◽  
Markus Reischer ◽  
Vicente Rives
Keyword(s):  
Layered Double Hydroxides ◽  
Chlorinated Solvents ◽  
Cost Effective ◽  
Water Remediation ◽  
Subsurface Water ◽  
Particle Injection ◽  
Global Issue ◽  
Cost Effective Method ◽  
Co Precipitation ◽  
Double Hydroxides

Nowadays, the contamination of groundwater and soils by highly hazardous and toxic chlorinated solvents is a global issue. Over the past years, different remediation strategies have been developed, involving injection of reactive solutions and/or particles. However, a major difficulty is the monitoring of injected particles during the injection and after secondary mobilisation by groundwater flow. This study is focussed on the development of directly traceable particles by combining fluorescein with Layered Double Hydroxides (LDHs). We present here the facile and easily tuneable synthesis of fluorescing LDHs (Fluo-LDH) via co-precipitation under supersaturation conditions. Their ability to mimic particle sizes of previously studied reactive LDHs, which proved to be able to adsorb or degrade chlorinated organic solvents from aqueous solutions, was investigated as well. Tests using a novel Optical Image Profiler (OIP) confirmed that the fluorescent LDHs can be easily detected with this tool. Even LDHs with the lowest amount of fluorescent dye were detectable. Together with the use of an OIP, which is capable of exciting the fluorescent material and collecting real-time pictures, this can provide a new, efficient, and cost-effective method for in situ tracing of injected particles in the subsurface.

scholarly journals Mixed Oxide Layered Double Hydroxide Materials: Synthesis, Characterization and Efficient Application for Mn2+ Removal from Synthetic Wastewater

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4089
Author(s):  
Cristina Modrogan ◽  
Simona Cǎprǎrescu ◽  
Annette Madelene Dǎncilǎ ◽  
Oanamari Daniela Orbuleț ◽  
Eugeniu Vasile ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Layered Double Hydroxides ◽  
Synthetic Wastewater ◽  
Precipitation Method ◽  
Metallic Ions ◽  
Materials Synthesis ◽  
Experimental Conditions ◽  
Edx Analysis ◽  
Co Precipitation ◽  
Double Hydroxides

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.

In‐Situ Incorporation of Pt Nanoparticles on Layered Double Hydroxides for Selective Conversion of Cinnamaldehyde to Cinnamyl Alcohol

2021 ◽  
Vol 6 (48) ◽  
pp. 13890-13896
Author(s):  
Jingmin Duan ◽  
Dan Wang ◽  
Rongqian Cui ◽  
Hongsong Zhang ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Pt Nanoparticles ◽  
Cinnamyl Alcohol ◽  
Selective Conversion ◽  
Double Hydroxides

scholarly journals Fumonisin B1 Interaction with Mg-Al and Mg-Fe Layered Double Hydroxides: Removal Efficiency and Mechanisms

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4344
Author(s):  
Jakub Matusik ◽  
Youjun Deng
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Layered Double Hydroxides ◽  
Lower Layer ◽  
Fumonisin B1 ◽  
Xrd Analysis ◽  
Layer Charge ◽  
Basal Spacing ◽  
Co Precipitation ◽  
Double Hydroxides

Mycotoxins in feed and food are highly toxic and pose a serious danger even at very low concentrations. The use of bentonites in animal diet can reduce toxin bioavailability. However, some mycotoxins like fumonisin B1 (FB1) form anionic species which excludes the use of negatively charged clays. Layered double hydroxides (LDH) with anion-exchange properties, in theory, can be perfect candidates to adsorb FB1. However, fundamental research on the use of LDH for mycotoxins removal is scarce and incomplete. Thus, the presented study was designed to explore such a possibility. The LDH materials with differing chemistry and layer charge were synthesized by co-precipitation both from metal nitrates and chlorides and were then tested for FB1 removal. XRD, FTIR, XPS, and chemical analysis were used for the LDH characterization and to obtain insight into the removal mechanisms. A higher adsorption capacity was observed for the Mg/Al LDH samples (~0.08–0.15 mol/kg) in comparison to the Mg/Fe LDH samples (~0.05–0.09 mol/kg) with no difference in removal efficiency between Cl and NO3 intercalated LDH. The adsorption capacity increased along with lower layer charge of Mg/Al and was attributed to the lower content of bonded carbonates and the increase of non-polar sites which led to matching between the adsorption domains of LDH with FB1. The FTIR analysis confirmed the negative effect of carbonates which hampered the adsorption at pH 7 and led to the highest adsorption at pH 5 (FB1 content ~15.8 ± 0.75 wt.%). The fast surface adsorption (1–2 min) was dominant and XRD analysis of the basal spacing indicated that no FB1 intercalation occurred in the LDH. The XPS confirmed a strong interaction of FB1 with Mg sites of LDH at pH 5 where the interaction with FB1 carboxylate moieties COO− was confirmed. The research confirmed a high affinity and selectivity of LDH structures towards anionic forms of FB1 mycotoxin.

In Situ Microstructural Control of Ni/Al2O3and Ni/NiAl2O4Composites from Layered Double Hydroxides

1997 ◽  
Vol 9 (2) ◽  
pp. 478-484 ◽  
Author(s):  
Eric D. Rodeghiero ◽  
Jungi Chisaki ◽  
Emmanuel P. Giannelis
Keyword(s):  
Layered Double Hydroxides ◽  
Double Hydroxides ◽  
Microstructural Control
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