Degradation mechanism of tributyl phosphate by UV/H2O2 treatment and parameters optimization towards the design of a pilot reactor

While activated sludge treatment is currently the preferred process for the removal of tributyl phosphate (TBP) at the mg.L−1 level, it is well known that this recalcitrant molecule is incompletely degraded, stimulating research into alternative approaches, such as advanced oxidation. The aim of this study was to characterize the degradation mechanism of TBP during ultraviolet/H2O2 treatment using 31P NMR, ionic chromatography and total organic carbon analysis. The effects of initial pH, amount of oxidant and pollutant concentration were also assessed using an experimental design approach. The results of this parametric study show that ultraviolet/H2O2 photo-oxidation efficiently degrades TBP at concentrations up to 600 mg.L−1, with >90% phosphate release and up to 95% removal of total organic carbon within 1 h. The data also show that the main reaction intermediates are short carboxylic acids, resulting from the released alkyl groups, meaning that an interesting application of this process may be to rapidly pre-treat industrial effluent upstream of activated sludge reactors

Décorporation des Actinides (synthèse et évaluation de systèmes chélatants spécifiques de U(VI))

The purpose of this PHD was the synthesis of new powerful chelating agent of uranium in physiological media for human decorporation. This work is a part of the Décorporation des Actinides program launched by the French organism CEA. To reach our objectives, chelating candidates should have association constants with the uranyl ion equal or superior to biological substances found in vivo. This criteria to reach sufficient complexation in vivo is found to be the only measurable property in vitro. During this work, four families of chelating agents were obtained. Analogues from EDTA and DTPA showed some affinity towards uranyl ions, insufficient regarding fixed objectives. Analogues of a know uranium decorporating agent (5-LICAMS) have been synthesized and show strong affinities toward uranium. One of them (CYCAMS) shows better complexation constants with uranyl ion than the 5-LICAMS. Finally, known uranyl chelating function such as HOPO of sulfocatechol have been attached to BINOL and pre-organizating scaffolds such as calixarenes. First complexation results are encouragingLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Evaluation des durées opératoires de soins dentaires sous anesthésie générale

CLERMONT FD-BCIU Odontol. (631132226) / SudocCLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Effects of Impregnated Amidophosphonate Ligand Concentration on the Uranium Extraction Behavior of Mesoporous Silica

A series of solid-phase uranium extractants were prepared by post-synthesis impregnation of a mesoporous silica support previously functionalized with octyl chains by direct silanization. Five materials were synthesized with 0, 0.2, 0.3, 0.4 and 0.5 mmol of the amidophosphonate ligand DEHCEBP per gram of functionalized solid, and the effect of the ligand concentration on the uranium extraction efficiency and selectivity of the materials was investigated. Nitrogen adsorption–desorption data show that with increasing ligand loadings, the specific surface area and average pore volume decrease as the amidophosphonate ligand fills first the micropores and then the mesopores of the support. Acidic uranium solutions with a high sulfate content were used to replicate the conditions in ore treatment leaching solutions. Considering the extraction kinetics, the equilibration time was found to increase with the ligand concentration, which can be explained by the clogging of micropores and the multilayer arrangement of the DEHCEBP molecules in the materials with their highest ligand contents. The fact that the equilibrium ligand/uranium ratio is about 2 mol/mol regardless of the ligand concentration in the material suggests that all the ligand molecules remain accessible for extraction. The maximum uranium extraction capacities ranged from 30 mg∙g−1 at 0.2 mmol∙g−1 DEHCEBP to 54 mg∙g−1 in the material with 0.5 mmol∙g−1 DEHCEBP. These materials could therefore potentially be used as solid-phase uranium extractants in acidic solutions with high sulfate concentrations

Récupération du palladium issu de lixiviat de déchets électroniques par des supports imprégnés

International audiencePrésentation générale des travaux de post do

Récupération de palladium issu de lixiviat de déchets électroniques

International audiencePrésentation très générale des travaux de post docs, ne présentant pas de lien avec la demande de brevet FD23160

Chanson patriotique à la suite de la bataille de Magenta et de notre entrée à Milan / signé : Ant. Leydier, père

Avec mode text

Amidophosphonate ligands as cerium extractants in supercritical CO2_2

International audienceIndustrial-scale rare earth extraction is typically performed by liquid-liquid extraction with large amounts of solvents, acids and organophosphorus ligands. An alternative is to use these extractants in supercritical CO$_2$ (SC-CO$_2$), where the crucial operating parameter is their solubility. Different molecules with amidophosphonate backbones have been synthesized and investigated in view of improving their solubility in SC-CO$_2$ and thereby their cerium extraction capacity. The CO$_2$-philicity of these extractants was adjusted by attaching branched or linear alkyl chains with four, six and eight carbons. Using a dynamic gravimetric setup, the solubility and cerium extraction capacity of these molecules were measured to vary from 1.56 to 2.47 mmol$_{ligand}$.mol$_{CO2}$$^{-1}$ and 0.25 to 0.46 mmol$_{Ce}$.mol$_{ligand}$$^{-1}$, respectively.The two properties were correlated and in both cases the highest values were obtained with a diisobutylamine chain. Solubility measurements between 313 and 331 K and between 13 and 28 MPa shows that optimal condition is (320 K ; 28 MPa)

Synthesis of organophosphorus ligands with a central oxygen atom and their applications in solvent extraction

International audienc