Miction

vignette|Un homme urinant dans un urinoir. La miction (du latin mingere, « uriner »), l'action d'uriner, désigne l'élimination d'urine par la vidange de la vessie. Description vignette|Loup gris urinant pour marquer son territoire. Les observations des mictions de mammifères d'une équipe du Georgia Institute of Technology ont mis en évidence en 2013 une loi expérimentale : la majorité des mammifères, quelle que soit leur taille et leur masse, mettent approximativement 21 secondes pour vider leur vessie. L'explication de ce phénomène est que la miction chez ces animaux est essentiellement dominée par la gravité : l'augmentation du mammifère en taille et en masse se traduit par un volume de vessie plus important et donc un volume d'urine qui devrait être plus long à évacuer, mais cela se traduit aussi par un urètre plus large et plus long qui permet d'augmenter proportionnellement le débit urinaire, d'où un temps de miction qui reste pratiquement identique. Cette loi ne s'a

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)

Guillaume Tissot

Iodinated X-ray contrast media (ICM) are persistent micropollutants in wastewater, which come mainly from hospital activities. Currently, there is no efficient method of treatment for this class of compounds, which leads to their increased presence in surface water and drinking water. In this work we propose to treat directly ICM in urine, meaning at high concentration, by electrochemical oxidation process using BDD electrodes. In a first step of the project, determination of the reactivity of Iohexol towards electrochemical oxidation in inactive electrolyte was performed. In subsequent iohexol electrolysis experiment the electrolyte composition was gradually modified until electrolysis of Iohexol in fresh urine. Obtained results were compared with those predicted by adjusted kinetic model of COD elimination. Model is based on the kinetic of the electrochemical oxidation is controlled by diffusion, and it was demonstrated, in this work, that this is also the case for the electrochemical oxidation of Iohexol. This methodology permits to determine interference that urine components such as chloride and ammonia have on the electrochemical oxidation. The obtained results showed that 99% of Iohexol present in the electrolyte and at least 85% of the initial COD elimination can be achieved with an efficiency close to 100%, even in fresh urine. Investigation of the main constituents of urine showed that chloride has a positive effect on the process efficiency due to both catalytic and no‐catalytic action (oxidation of organics compounds, via electrogenereted active chlorine, close to the electrode or in the bulk). On the contrary ammonia has no effect on the efficiency if it is present alone, and negative effect if chloride is also present (certainly due to chloramine formation). Nevertheless, at high concentration of ICM, the effect of chloride and ammonia is negligible as experiment in fresh urine demonstrated. As expected, the reaction of hydroxyl radical with Iohexol is non-specific. Preliminary identifications of transformation products by UPLC-MS showed that electrochemical oxidation can lead to nucleus attack (deiodination) or side chain attack unselectively. In addition, deiodination by cathodic reduction under mass transfer control is also possible according to these UPLC‐MS results, and by the kinetic of Iohexol elimination. At an elimination of 85% COD in treated urine only a very low concentration of pollutant remain. Ecotoxicity and biodegradability analyses were performed with the treated urine at this point. Toxicity assays showed some ecological toxicity towards environment; biodegradability test didn’t show clear biodegradation. Finally, operating cost analysis for a possible installation using electrochemical oxidation process with BDD electrodes showed that even if other advanced oxidation process (AOPs), such as processes such as ozonation or UV/H2O2, demonstrate the same efficiency as electrochemical oxidation in the future, electrochemical oxydation using BDD electrode remains strongly competitive economically.

2012

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)

Guillaume Tissot

2012

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)

Surgical Access And Stimulation Of Pudendal Nerve In Pigs To Restore The Micturition Control

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)

Surgical Access And Stimulation Of Pudendal Nerve In Pigs To Restore The Micturition Control

Miction

Investigation of the Electrochemical Destruction of X-­ray Contrast Media using Boron-­‐Doped Diamond Electrodes (BDD)

Surgical Access And Stimulation Of Pudendal Nerve In Pigs To Restore The Micturition Control

Investigation of the Electrochemical Destruction of X-­ray Contrast Media using Boron-­‐Doped Diamond Electrodes (BDD)

Surgical Access And Stimulation Of Pudendal Nerve In Pigs To Restore The Micturition Control

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)

Investigation of the Electrochemical Destruction of X-ray Contrast Media using Boron-‐Doped Diamond Electrodes (BDD)