Download or read book Etude de la d contamination par d gradation photocatalytique d eau contamin e par de la tylosine written by Julie Bertrou and published by . This book was released on 2015 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: La dépollution de l’eau est un sujet de santé publique majeur. La pollution par des médicaments, notamment par des antibiotiques rejetés dans les excréments des animaux d’élevage, est importante et leur élimination doit être une priorité. L’objet de cette thèse d’exercice est d’étudier la dégradation par photocatalyse d’un antibiotique vétérinaire, la tylosine.

Download or read book Proc d photocatalytique de d contamination des effluents liquides contamin s par des r sidus de m dicaments written by Amélie Le Freche and published by . This book was released on 2013 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: La détection de traces de médicaments dans l’eau potable et dans les eaux de surface soulève un problème de pollution pour l’environnement et de santé publique. Ce travail développe l’étude de la dégradation de résidus d’antibiotiques dans l’eau à travers la dégradation d’un mélange de sulfaméthoxazole - tylosine puis de l’amoxicilline par la méthode de photocatalyse hétérogène. Les antibiotiques ont la particularité d’être une classe thérapeutique pour laquelle il existe des bactéries résistantes. L’efficacité de ces médicaments est donc diminuée. Afin de traiter les eaux usées, de nombreuses opérations sont utilisées en station d’épuration et en sortie d’usine mais elles ne permettent pas actuellement l’élimination complète des antibiotiques. Des méthodes complémentaires sont donc actuellement en étude. L’une d’entre elles, objet de ce travail, est la photocatalyse hétérogène. Cette technique d’oxydation avancée est fondée sur l’utilisation d’un photocatalyseur (dioxyde de titane) activé par un rayonnement UV. Elle vise à la dégradation des polluants aromatiques (colorants, pesticides), des phénols et des métaux. Toutes les expériences de l’étude sont basées sur le même protocole. L’impact des paramètres tels que le pH, la concentration et le type de photocatalyseur ont été analysés afin de déterminer leur influence sur la dégradation. L’ensemble des expériences menées a mis en évidence l’efficacité de la photocatalyse sur la dégradation de certaines molécules d’antibiotiques. L’étude de la dégradation du mélange sulfaméthoxazole - tylosine conclue qu’à même concentration, les deux antibiotiques sont dégradés en même temps et donc qu’il n’y a pas de compétition entre ces deux molécules. Les expériences sur la dégradation de l’amoxicilline mettent en évidence l’importance des paramètres de la photocatalyse. A forte concentration, la dégradation est moins efficace. Le photocatalyseur qui apparait le plus efficace est celui le plus concentré en dioxyde de titane. Enfin l’étude cinétique de la dégradation de l’amoxicilline valide le modèle de Langmuir-Hinshelwood pour de faibles concentrations. Cette étude repose sur l’impact des résidus médicamenteux sur l’environnement et l’importance des moyens à mettre en œuvre pour les éliminer. L’ensemble des intervenants dans le cycle du médicament a une responsabilité dans ce processus et se doit d’agir en conséquence.

Download or read book D contamination microbiologique de l eau tude d une nouvelle approche written by Christine Koch and published by . This book was released on 2015 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photocatalytic Degradation of Organic Contaminants in Water written by Youn-Chul Oh and published by . This book was released on 2004 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation concerns the elucidation of degradation mechanisms of organic contaminants in aqueous suspension of TiO2, and extending understanding of photo catalysis condition to optimize degradation efficiency. The degradation mechanism of maleic acid, an important intermediate from the photocatalytic degradation of aromatic contaminants, was investigated via product distribution study and control experiments. The understanding of the mechanism of degradation of these compounds can assist us in ascertaining ideal conditions to perform the mineralization of recalcitrant organic compounds. The challenge to degrade a cyanyric acid, a recalcitrant species, by modifying TiO2 suspension was carried out. The addition of fluoride to aqueous suspensions of TiO2 has proved to be an important mechanistic tool in unraveling a long-standing conundrum in photocatalytic degradation. By using this method in parallel with other methods for producing homogeneous hydroxyl-type reagents, it is shown that cyanuric acid is susceptible to degradation under easily accessible conditions. There are isotope studies of photocatalysis of dimethyl phenyl phosphonate, a simple and safe form of organic phosphonate. Exposure of DMMP and related simple phosphonates to TiO2-mediated photocatalytic conditions results first in the loss of one of the methyl esters. An important unsettled mechanistic point is the mechanism by which the methyl is removed. Through the isotope studies of TiO2-mediated photocatalytic degradation of phosphonates, we can now understand removal of the alkyl ester portion of the compounds to produce phosphonic acid monoesters among the primary steps. The retention of 18O in the formation of MMPP clearly demonstrates that the dealkylation mechanism involves degradation of the methyl group exclusively, and neither attack at phosphorous by HO[Multiplied by][Subscript ads] or a related species, nor photoinduced hydrolysis. With an attempt to activate the modified TiO2 photo catalysts by the visible light and decrease the rapid recombination of excited electrons/holes during photoreaction, WO[Subscript x]-TiO2 powder was prepared by a sol-gel method. The WO[Subscript x]-TiO2 catalysts were characterized by XRD, XPS, and SEM-EDX. The degradation of 4-methoxyresorcinol by using WO[Subscript x]-TiO2 under visible light irradiation was observed.

Download or read book Photo catalytic Degradation of Organic Water Pollutants Energy Efficiency and Kinetic Modeling written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Etude de la qualit de l eau potable dans un r seau de distribution par apprentissage statistique written by Zineb Noumir and published by . This book was released on 2012 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: La sûreté des systèmes d’approvisionnement d’eau potable est essentielle pour la santé publique. Un réseau de distribution d’eau est typiquement constitué d’usines de production, de châteaux d’eau, de réservoirs, de pompes etc. Un tel type d’infrastructure est particulièrement difficile à protéger et à surveiller. Le chlore, injecté dans les usines de productions, a un double intérêt. C’est tout d’abord un puissant oxydant qui inactive les agents viraux ou bactériens sensibles. C’est également un traceur de la qualité de l’eau et de l’intégrité du réseau de distribution, la présence d’un contaminant dans le réseau entraîne immédiatement une consommation anormale de chlore. C’est sur ce deuxième point que se situe les travaux de cette thèse. L’objectif de cette thèse consiste à détecter la présence d’un contaminant dans le réseau, et à fournir une classification du type de contaminant, afin que l’exploitant prenne les décisions opérationnelles adéquates. Dû à la complexité des réseaux traités et à la diversité des substances contaminantes, une mise en oeuvre de modèles paramétriques ne peut hélas être exploitée. Les méthodes d’apprentissage statistique permettent de contourner ses difficultés. Ainsi cette thèse est-elle structurée autour de deux axes de recherche principaux, qui sont la classification multi-classes et la détection par apprentissage, et qu’il convient d’étudier au jour de mesures issues de capteurs de chlore pour une implémentation industrielle en temps réel

Download or read book Antimicrobial Resistance in Developing Countries written by Aníbal de J. Sosa and published by Springer Science & Business Media. This book was released on 2009-10-08 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: Avoiding infection has always been expensive. Some human populations escaped tropical infections by migrating into cold climates but then had to procure fuel, warm clothing, durable housing, and crops from a short growing season. Waterborne infections were averted by owning your own well or supporting a community reservoir. Everyone got vaccines in rich countries, while people in others got them later if at all. Antimicrobial agents seemed at first to be an exception. They did not need to be delivered through a cold chain and to everyone, as vaccines did. They had to be given only to infected patients and often then as relatively cheap injectables or pills off a shelf for only a few days to get astonishing cures. Antimicrobials not only were better than most other innovations but also reached more of the world’s people sooner. The problem appeared later. After each new antimicrobial became widely used, genes expressing resistance to it began to emerge and spread through bacterial populations. Patients infected with bacteria expressing such resistance genes then failed treatment and remained infected or died. Growing resistance to antimicrobial agents began to take away more and more of the cures that the agents had brought.

Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.

Download or read book Ozonation of Water and Waste Water written by Christiane Gottschalk and published by John Wiley & Sons. This book was released on 2009-12-09 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The leading resource on ozone technology, this book contains everything from chemical basics to technical and economic concerns. The text has been updated to include the latest developments in water treatment and industrial processes. Following an introduction, the first part looks at toxicology, reaction mechanisms and full-scale applications, while Part B covers experimental design, equipment and analytical methods, mass transfer, reaction kinetics and the application of ozone in combined processes.

Download or read book Olive Processing Waste Management written by Michael Niaounakis and published by Elsevier. This book was released on 2006-02-01 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: Olive Processing Waste Management contains a comprehensive review of literature and patent survey concerning olive processing waste. Over 1,000 citations are presented. Wastes considered include olive cultivation solid waste, wastes arising from classical, three- and two-phase olive mills and wastes generated during table olive processing. In addition, information is presented concerning the management of spent olive oil (e.g. from cooking). The book is divided into five parts. Part I presents background information concerning the characterization of olive processing wastes, their environmental impacts if disposed untreated and the effect of utilised olive-mill technology on the quantity and quality of generated wastes. Part II presents physical, thermal, physico-chemical, biological and combined or miscellaneous processes for treating olive-mill wastes. Part III concerns information on utilization of such wastes with or without prior treatment. Part IV concentrates on table olive processing waste and presents information regarding its characterization, treatment and uses. Part V presents an economical and legislative overview regarding olive-mill waste. The book contains a bibliography, glossary of terms used in the text, subject, patent and author indices as well as pertinent internet sites and authorities. - Complete coverage of all available literature and patents concerning olive processing waste including economic and legislative issues - Critical review of up to date utilized processes concerning treatment and uses of such waste - Determination of research needs for further utilization of such wastes

Download or read book Mycotoxins and Food Safety written by Jonathan W. DeVries and published by Springer Science & Business Media. This book was released on 2002-03-31 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mycotoxins, from the Greek "mukes" referring to fungi or slime molds and toxin from the Latin "toxicum" referencing a poison for arrows, have earned their reputation for being potentially deleterious to the health and well being of a consuming organism, whether it be animal or human. Unfortunately, mycotoxins are a ubiquitous factor in the natural life cycle of food producing plants. As such, control of the potential impact of mycotoxins on food safety relies heavily upon accurate analysis and surveys followed by commodity segregation and restricted use or decontamination through processing. The purpose of this book is to provide the most comprehensive and current information on the topic of mycotoxins and assuring food safety. Chapters represented in the book reflect such diverse topics ranging from occurrence and impact, analysis, reduction through processing and plant breeding, toxicology and safety assessments to regulatory perspectives. Authors represent a range of international perspectives.