Layered double hydroxides from aluminum saline slags applied in adsorption and photocatalysis processes for the removal of emerging pollutants

2020 ◽  
Author(s):  
◽  
Leticia Santamaría Arana
Keyword(s):  
Salicylic Acid ◽  
Layered Double Hydroxides ◽  
Emerging Contaminants ◽  
Pharmaceutical Compounds ◽  
Emerging Pollutants ◽  
Removal Of Contaminants ◽  
Double Hydroxides

The objective of the work studied here was to synthesize Layered Double Hydroxides (LDH) with aluminum extracted from saline slags and test their function once calcined into adsorbents/catalysts for use in the removal of emerging contaminants (pharmaceutical compounds) from aqueous media.Two different techniques for the removal of contaminants were tested, adsorption and photocatalysis. In the present work, a new procedure for the recovery of aluminum present in saline slags generated during the secondary recycling processes of aluminum as adsorbent/photocatalyst of diclofenac and salicylic acid, as examples of emerging contaminants, has been reported. Results obtained have been extensively analyzed throughout the present study.

Effect of salicylic acid intercalated layered double hydroxides on ultraviolet aging properties of bitumen

2015 ◽  
Vol 49 (4) ◽  
pp. 1235-1244 ◽  
Author(s):  
Song Xu ◽  
Jianying Yu ◽  
Canlin Zhang ◽  
Tingting Yao ◽  
Yubin Sun
Keyword(s):  
Salicylic Acid ◽  
Layered Double Hydroxides ◽  
Aging Properties ◽  
Double Hydroxides ◽  
Ultraviolet Aging

scholarly journals ZnTi layered double hydroxides as photocatalysts for salicylic acid degradation under visible light irradiation

2020 ◽  
Vol 197 ◽  
pp. 105757 ◽  
Author(s):  
Radu G. Ciocarlan ◽  
Hao Wang ◽  
Bert Cuypers ◽  
Myrjam Mertens ◽  
Yan Wu ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Layered Double Hydroxides ◽  
Light Irradiation ◽  
Acid Degradation ◽  
Double Hydroxides

scholarly journals Detection of emerging pollutants in ocean waters around king george Island, Antarctica

2020 ◽  
Vol 4 (5) ◽  
pp. 191-197
Author(s):  
Ozelito Possidonio de Amarante Junior ◽  
Maccarena Marcotti-Murua ◽  
Felipe Sotomayor Stephens
Keyword(s):  
Salicylic Acid ◽  
Bisphenol A ◽  
Organic Contaminants ◽  
Emerging Contaminants ◽  
Emerging Pollutants ◽  
Organic Substances ◽  
King George Island ◽  
Antifouling Paints ◽  
Low Levels ◽  
Wide Group

Emerging contaminants are a wide group of compounds that include several classes of organic substances. Personal care products, pharmaceuticals, pesticides, industrial additives, monomers and plasticizers are examples of compounds included in emerging contaminants. In this work, four chemicals representing four classes of organic contaminants were investigated: salicylic acid, representing drugs; bisphenol A, a monomer widely used in the production of polymeric products; methylparaben, used as a preservative in cosmetics; and irgarol, a biocide used in agriculture and antifouling paints. A previously validated method based on liquid chromatography coupled with mass spectrometry was employed to determine the trace-levels of those compounds in ocean waters around King George Island, Antarctica. Salicylic acid and bisphenol A were found in many of the 20 samples investigated, which were collected on the northwest and southeast coasts of the island. Methylparaben and irgarol were found at low levels, each with only one occurrence. Although salicylic acid may originate in the biosynthesis of phenylalanine, the distribution and absence of this substance at some points suggest an anthropic origin. Bisphenol A was found in several sampling points, demonstrating contamination by plastics even though no correlation was found between these two compounds.

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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