Dissertations / Theses on the topic 'Organici Volatili'

L’oggetto del presente lavoro di tesi è stato la riduzione della concentrazione di composti organici volatili (COV) nelle correnti gassose emesse ai camini di uno stabilimento per la produzione di vernici, al fine di portarne il valore al di sotto del limite ammesso dalle norme di legge. La classe dei composti organici volatili comprende numerosi composti chimici con proprietà fisiche e chimiche differenti, ma accomunati da un'elevata volatilità. I COV possono provenire da fonti naturali o da processi umani. Si è stimato che le fonti antropogeniche emettano complessivamente a livello mondiale circa 142∙10E+06 ton/anno di carbonio sotto forma di composti organici volatili, provenienti dai derivati del petrolio, dai prodotti delle combustioni, dalle vernici e dai rivestimenti; nello specifico la produzione mondiale di vernici e di rivestimenti è stimata pari a 12∙10E+09 litri/anno e in essa i COV antropogenici trovano largo utilizzo come solventi. Per contenere l’esponenziale aumento dei COV in atmosfera, vengono istituite regolamentazioni sempre più stringenti, che costringono le industrie di vernici a intervenire sui loro processi al fine di ridurre l’emissione di COV. Gli interventi e le tecnologie convenzionali per abbattere i COV nei processi industriali sono la filtrazione per adsorbimento con il filtro a carboni attivi o la degradazione termica con il post-combustore. Queste tecnologie hanno alti costi operativi e di manutenzione, e non intervengono risolvendo il problema alla radice, bensì sono impiegate in coda al processo produttivo, trascurando le inefficienze della gestione dei COV a monte. Nello stabilimento oggetto del presente lavoro di tesi l’abbattimento delle concentrazioni di COV al camino è stato ottenuto intervenendo direttamente sul processo produttivo, consentendo non solo di soddisfare i necessari requisiti di protezione ambientale, ma anche di ottenere un notevole risparmio economico, a causa della minore perdita di solventi.

Negli ultimi anni si osserva una richiesta sempre maggiore da parte del mercato di materiali più sostenibili dal punto di vista ambientale. Le aziende hanno quindi iniziato a studiare soluzioni alternative, tra queste l’impiego di materiali riciclati e biodegradabili. Nell’ambito degli imballaggi a contatto con alimenti risulta importante utilizzare materiali che non rilascino composti nel prodotto contenuto ed è quindi necessario poter controllare la presenza di sostanze volatili (VOCs) e semivolatili (SVOCs) legate alla materia prima e al processo produttivo. Per questo motivo, si è messo a punto un metodo di analisi dei composti volatili presenti in matrici di polietilene ad alta densità riciclato (r-HDPE) e polidrossialcanoati (PHA) tramite GC-MS preceduta da estrazione di VOCs in spazio di testa. Si sono poi confrontati i risultati ottenuti dalle analisi dei materiali di partenza con quelli ottenuti sui prodotti stampati a compressione, con lo scopo di capire se e come il processo produttivo potesse influire sul contenuto di analiti presenti nel campione. I risultati evidenziano come il profilo di volatili dell’HDPE riciclato sia strettamente collegato a quello dell’HDPE vergine (alcani lineari e ramificati) ma presenti composti aggiuntivi soltanto nei materiali riciclati. I VOCs caratteristici dei PHA sono invece aldeidi, alcoli e strutture ramificate con atomi di ossigeno sulla catena e risultano molto diversi a seconda della struttura del materiale considerato. È stato inoltre studiato per i PHA se, imponendo stress termico e meccanico a un campione, si formino nuovi composti in seguito a degradazione.

A relevant problem of polyolefins processing is the presence of volatile and semi-volatile compounds (VOCs and SVOCs) such as linear chains alkanes found out in final products. These VOCs can be detected by customers from the unpleasant smelt and can be an environmental issue, at the same time they can cause negative side effects during process. Since no previously standardized analytical techniques for polymeric matrix are available in bibliography, we have implemented different VOCs extraction methods and gaschromatographic analysis for quali-quantitative studies of such compounds. In literature different procedures can be found including microwave extraction (MAE) and thermo desorption (TDS) used with different purposes. TDS coupled with GC-MS are necessary for the identification of different compounds in the polymer matrix. Although the quantitative determination is complex, the results obtained from TDS/GC-MS show that by-products are mainly linear chains oligomers with even number of carbon in a C8-C22 range (for HDPE). In order to quantify these linear alkanes by-products, a more accurate GC-FID determination with internal standard has been run on MAE extracts. Regardless the type of extruder used, it is difficult to distinguish the effect of the various processes, which in any case entails having a lower-boiling substance content, lower than the corresponding virgin polymer. The two HDPEs studied can be distinguished on the basis of the quantity of analytes found, therefore the production process is mainly responsible for the amount of VOCs and SVOCs observed. The extruder technology used by Sacmi SC allows to obtain a significant reduction in VOCs compared to the conventional screw system. Thus, the result is significantly important as a lower quantity of volatile substances certainly leads to a lower migration of such materials, especially when used for food packaging.

Questo lavoro nasce dalla lettura di un articolo scientifico del 1989 dove si illustra un concetto rivoluzionario per l’epoca: alcune piante ornamentali sono in grado di abbattere i composti organici volatili in ambienti chiusi. Lo scopo che ci si è proposti è stato quello di raccogliere tutti gli elementi necessari per costruire uno strumento in grado di valutare l’effetto dell’introduzione di piante ornamentali in un definito ambiente. Si è quindi proposto un modello,un semplice bilancio di materia che assume il volume di aria come perfettamente miscelato, che permette di prevedere le variazioni di concentrazione dei composti organici volatili in funzione del rateo di ventilazione dell’ambiente in esame, della concentrazione dell’aria esterna, delle sorgenti emissive e dell’area fogliare presente. Il contributo di rimozione da parte delle piante, l’elemento di novità introdotto, è espresso in relazione alla superficie fogliare considerando l’abbattimento dei composti organici volatili come una reazione di pseudo-adsorbimento. Con tale modello è quindi possibile valutare in prima approssimazione l’impatto dell’inserimento di una data area fogliare in un definito ambiente indoor oltre che determinare l’area fogliare necessaria per ottenere una determinata efficienza di abbattimento. I principali limiti sono i seguenti: viene trascurata la dispersione, si considera solo la rimozione da parte delle piante trascurando altri “sink” e non viene incluso un contributo per la reattività dei contaminanti. Tale modello vuole essere un primo strumento per la progettazione di interventi di mitigazione con piante ornamentali per il controllo della qualità dell’aria indoor i quali portano il vantaggio di presentare costi ridotti e bassi impatti ambientali (inoltre le specie esaminate sono potenzialmente in grado di abbattere anche concentrazioni molto basse). Tra gli svantaggi, sicuramente il principale è la loro efficienza di abbattimento variabile e non sempre prevedibile.

L’obiettivo della ricerca sperimentale condotta è di valutare la possibile applicabilità di fiocchi di fibre di polistirene sindiotattico come materiale adsorbente da utilizzare nel processo di depurazione delle acque reflue. Il trattamento che potrebbe prevedere l’impiego dei fiocchi di fibre di polistirene sindiotattico è l’adsorbimento. Questo processo di separazione consiste nel trasferimento di uno o più componenti di una fase fluida sulla superficie di un solido poroso. Il mezzo adsorbente di comune impiego è il carbone attivo, per le elevate superfici specifiche e la buona affinità con un grande numero di composti. Il limite di questo materiale riguarda i costi, in particolare di rigenerazione e smaltimento. Le valutazioni economiche, determinanti ai fini dello sviluppo di processo, hanno spostato l’interesse verso materiali facilmente reperibili e che richiedono minori costi di gestione. Affinché si possa pensare di impiegare un materiale come adsorbente questo deve presentare caratteristiche chimico – fisiche che lo rendano idoneo all’applicazione. I fiocchi di fibre di polistirene sindiotattico, se sottoposti ad uno specifico trattamento con solventi, cristallizzano nella forma cristallina delta nanoporosa. In questo modo si ottiene un materiale che coniuga le proprietà dei sistemi porosi con le caratteristiche dei polimeri quali resistenza, basso costo, durabilità e facile processabilità. Il processo di adsorbimento di sostanze volatili in matrici acquose è generalmente condotto in colonne a letto fisso. La ricerca eseguita si può suddividere in due fasi, distinte innanzitutto da una specifica di progetto cioè la quantità di materiale adsorbente caricato in colonna. L’utilizzo di quantità di polimero piuttosto differenti, anche in termini di volume, ha reso necessario lo svolgimento delle prove con un diverso apparato sperimentale e ha permesso la valutazione di aspetti differenti del fenomeno.

Negli ultimi anni, l’aumentata sensibilità per le problematiche ambientali ha orientato l’attenzione verso la qualità dell’aria. Gli studi epidemiologici e la consapevolezza che le condizioni di salute della popolazione siano direttamente correlate alla concentrazione di inquinanti presenti in atmosfera, hanno fatto sì che venisse affrontata più concretamente la questione delle emissioni. In particolare le emissioni di solventi organici rappresentano un problema concreto a causa del loro ampio utilizzo in diversi settori industriali. All’interno di un contesto normativo che tutela la qualità dell’aria imponendo soglie e limiti, gli operatori dei settori produttivi devono adeguarsi a tecnologie più consone al rispetto ambientale. Una tecnica di abbattimento biologico come la Biofiltrazione può rispondere a queste esigenze sfruttando la capacità dei microrganismi di degradare i composti organici che compongono i gas esausti. Il lavoro descritto in questo elaborato di tesi è consistito nell’isolamento di microrganismi in grado di catabolizzare i più comuni solventi organici e nella verifica della loro attività inoculandoli in reattori simulanti un biofiltro. Lo scopo è stato quello di individuare popolazioni idonee all’arricchimento del pool catabolico di impianti di biofiltrazione in fase di avviamento. A partire da tre campioni si sono quindi isolati ceppi sotto la pressione selettiva positivi alla catabolisi dei composti target attraverso l’esposizione dei microrganismi al solvente in fase vapore. Successivamente ogni ceppo isolato è stato sottoposto a test di positività sulla capacità di biodegradazione della molecola induttrice attraverso un sistema respirometrico proposto da Bartha et al. (1965) che valuta l’attività catabolica mediante la produzione di CO2. Infine si è analizzata l’azione di questi microrganismi all’interno di reattori pilota simulanti l’attività di un biofiltro misurando l’efficienza di abbattimento con un sistema in discontinuo (Fialette a carboni attivi ed analisi gas-cromatografica GC FID) e con alcuni confronti con un fotoionizzatore in continuo (PID).

I processi microbiologici rivestono una grande importanza nello sviluppo di combustibili e sostanze chimiche da fonti rinnovabili (biomassa), quali: il biometano e le bioplastiche, come i poli(idrossialcanoati), PHA. I PHA sono poliesteri ottenuti per condensazione di 3-idrossiacidi, il più comune dei quali è il poli(3-idrossibutirrato, PHB). Gli alti costi di produzione del PHA da colture microbiche singole ha portato a valutare nuove strategie, tra cui l’utilizzo di colture microbiche miste (MMC) e substrati di scarto. Il bio-olio ottenuto dalla pirolisi di biomassa potrebbe essere un substrato interessante per la produzione di biogas e PHA. Gli acidi a catena corta (acidi grassi volatili, VFA), infatti, sono i prodotti intermedi nella produzione sia di biogas che di PHA. L’analisi di questi ultimi viene normalmente effettuata tramite GC-FID o GC-MS. La degradazione termica (pirolisi, Py) di PHA produce acidi alchenoici caratteristici, come l’acido crotonico. Il metodo tradizionale per la determinazione del PHA è la metanolisi seguita da un’analisi GC-MS, una procedura laboriosa con uso di solventi clorurati e sostanze corrosive. Lo scopo principale di questa tesi è stato quello di sviluppare un nuovo metodo di analisi dei PHA. Il metodo studiato si basa sulla pirolisi diretta della biomassa e determinazione degli acidi alchenoici prodotti dalla degradazione del PHA in GC-FID. La pirolisi analitica è stata studiata tramite analisi di polimeri puri (per la calibrazione) e poi è stata applicata a campioni batterici derivanti da MMC e a ceppi selezionati. Il confronto con il metodo convenzionale ha dimostrato che la Py/GC-FID è un metodo valido per l’identificazione dei PHA e per la loro quantificazione nelle matrici batteriche. Il pre-trattamento del campione è minimo e non richiede l’uso di solventi e reagenti chimici. Inoltre, è stata applicata una tecnica di analisi dei VFA nei test di biometanazione basata sull’estrazione con una microquantità di dimetilcarbonato.

I rifiuti organici e i fanghi di depurazione rappresentano i due maggiori flussi di scarto del metabolismo urbano. L’obiettivo di questo lavoro di tesi consiste nella loro valorizzazione attraverso l’ottimizzazione della produzione di acidi grassi volatili (AGV) mediante fermentazione e successivamente attraverso la produzione di biogas mediante digestione anaerobica dell’effluente della fermentazione. Entrambi i processi di fermentazione e biometanazione sono stati condotti in condizioni mesofile, a T=37°C e T=42°C rispettivamente. I rifiuti organici e i fanghi di depurazione sono stati miscelati in rapporto 1:1 su base TVS e sottoposti a cavitazione. La resa di AGV è stata determinata per la miscela cavitata e non cavitata su un primo test batch con un carico organico (OL) pari a 21,4 kgtCOD/m3 e 22,4 kgtCOD/m3 per la miscela cavitata e non cavitata rispettivamente. Nel secondo test batch è stato applicato un carico organico pari a 33,4 e 34,8 kgtCOD/m3 rispettivamente per la miscela cavitata e non cavitata. Dopo aver raggiunto il picco della concentrazione dei VFA, i due reattori sono stati alimentati in semi-continuo con un tasso di carico organico (Organic Loading Rate, OLR) pari a 8 kgTVS/m3*d ed un tempo di ritenzione idraulica (Hydraulic Retention Time, HRT) pari a 5 d e 6,6 d per il substrato cavitato e non cavitato rispettivamente. I test di biometanazione sono stati condotti sui substrati singoli (rifiuti organici e fanghi di depurazione), sulla miscela di rifiuti organici e fanghi cavitata e non cavitata in rapporto 1:1 su base TVS, sull’effluente della fermentazione di queste due miscele e sulla sua frazione solida. Organic waste and biological sludge produced from wastewater treatment plants are the two major waste streams of the urban metabolism. The aim of this thesis is their valorization by optimizing the production of volatile fatty acids (AGVs) through fermentation and subsequent biogas production through the anaerobic digestion of the fermentation effluent. Both processes of fermentation and biomethanation were conducted under mesophilic conditions, with T=37°C and T=42°C respectively. Organic waste and biological sludge were mixed at a 1:1 ratio on TVS basis and then cavitated. The VFAs yield was determined for the cavitated and untreated mixture by carrying out a batch test with an organic loading (OL) of 21,4 kgtCOD/m3 and 22,4 kgtCOD/m3 for the cavitated and untreated mixture respectively. A second batch test was conducted, with an OL of 33,4 and 34,8 kgtCOD/m3 for the cavitated and untreated mixture respectively. After reaching the peak in VFAs production, both reactors were fed in a semi-continuous manner with an organic loading rate (OLR) of 8 kgTVS/m3*d and a hydraulic retention time (HRT) of 5 d and 6,6 d for the cavitated and untreated mixture respectively. The biochemical methane potential (BMP) tests were conducted on the single substrates (organic waste and biological sludge), on the mixture of organic waste and biological sludge cavitated and untreated in a 1:1 ratio on TVS basis, and finally on the fermentation effluent of the two mixtures and on its solid fraction.

Negli ultimi anni il settore del pet food ha registrato un forte incremento di interesse, spingendo le aziende produttrici ad indagare sulle variabili che incidono maggiormente sul gradimento, da parte degli animali domestici, degli alimenti a loro destinati. Si è riscontrato come, per cani e gatti, l’olfatto sia determinante per l’apprezzamento di un prodotto. Tale elaborato di tesi ha lo scopo di indagare alcuni prodotti destinati all’alimentazione degli animali, le crocchette per gatti, attraverso metodi analitici per la valutazione quali-quantitativa del profilo aromatico ed elementi di analisi sensoriale. L’elaborazione congiunta dei risultati strumentali (profilo in composti volatili) con quelli sensoriali (gradimento olfattivo da parte degli animali) risulta fondamentale per ottenere una valutazione complessiva dell’aroma del prodotto, consentendo di individuare quali possano essere i composti volatili che influenzano le preferenze alimentari dei gatti. La ricerca bibliografica iniziale è stata propedeutica per la realizzazione di una ricerca sperimentale focalizzata su 42 campioni commerciali di crocchette per gatti. Dalle analisi effettuate mediante metodologia HS-SPME-GC-MS sono stati identificati un totale di 52 composti volatili. Grazie ad un’elaborazione statistica dei risultati mediante PCA è stato possibile selezionare 36 variabili (composti volatili) maggiormente discriminanti nella caratterizzazione dei campioni. Infine, sono state esaminate le principali analogie e differenze nel profilo in composti volatili tra i campioni analizzati, anche in relazione agli ingredienti, sono state identificate le molecole caratterizzanti i campioni e, per alcune di queste, sono stati ricercati in letteratura i relativi sentori aromatici. Per questo motivo risulta essenziale continuare questi studi al fine di formulare alimenti sempre più appetibili, sostenibili e competitivi.

È comunemente accettato che il cambiamento climatico sia dovuto ad un effetto antropico. Gli agenti inquinati sono sicuramente responsabili del peggioramento della qualità della vita umana ed è necessario trovare una soluzione. Una importante classe di inquinati è quella dei Composti Organici Volatili (VOC). Molti di questi composti sono classificati come cancerogeni o possibili cancerogeni per le persone, oltre al fatto che possono causare danni a lungo termine sull'ambiente. Nonostante questi problemi, i VOC sono necessari nelle vernici di pareti o arredi, nei trattamenti dei tessuti e sono largamente utilizzati nei processi industriali, per poi essere rilasciati nell'ambiente come prodotti di scarico. Al momento, però, non è possibile sostituirli con altri composti meno dannosi, pertanto è necessario concentrarsi sulla loro degradazione dopo la diffusione nell'aria. Il modo più facile è tramite i reattori di combustione, ma sono molto ingombranti, richiedono molta energia ed è necessario raggiungere temperature superiori ai 300°C per essere efficaci. I plasmi a pressione atmosferica, in particolare le Surface Dielectric Barrier Discharge (SDBD), possono essere di aiuto nel miglioramento dell'abbattimento dei VOC. Infatti le SDBD richiedono molta meno energia dei tipici reattori di combustione, occupano volumi molto minori (generalmente meno di un metro cubo) e la temperatura globale del gas è dell'ordine della temperatura ambiente. L'inquinamento da agenti chimici non è l'unico problema che dobbiamo affrontare per migliorare la qualità della vita. L'antibiotico resistenza è un problema crescente. I farmaci antibiotici hanno migliorato nettamente le condizioni di salute sin dal momento in cui sono stati scoperti, ma stanno diventando via via sempre meno efficienti a causa dell'uso improprio che è stato fatto negli ultimi decenni. Un modo per contrastare l'uso di antibiotici è quello di ridurre o eliminare le cariche batteriche presenti nell'aria, ad esempio usando filtri antiparticolato nei sistemi di ventilazione. In questo modo però gli agenti biologici sono raccolti nei filtri in modo passivo; vengono accumulati, possono proliferare sul lungo periodo specialmente in presenza di alta umidità (>80%), e venire successivamente ridiffusi. Parte di questa tesi si occupa di studiare una possibile soluzione a questo problema. Si fa uso di una SDBD in modo innovativo per ridurre la concentrazione di batteri nell'aria. Il volume ridotto delle SDBD permette di inserire questo sistema all'interno dei sistemi di ventilazione e di ridurre attivamente la carica microbica al loro interno. L'ultima parte della tesi si concentra sulla modifica di superfici polimeriche attraverso l'uso di un plasma freddo capacitivo a bassa pressione. Negli ultimi decenni si sta sviluppando un crescente interesse nei materiali nanostrutturati. Tramite il plasma è possibile creare una nanostrutturazione sulle superfici polimeriche per diverse applicazioni, come ad esempio superfici antifouling in acqua o antibatteriche in aria.
It is generally accepted that the reduction of life quality is largely due to anthropic effects, mainly due to pollutant agents, and possible solutions need to be addressed. An important class pollutants are the so-called Volatile Organic Compounds (VOCs). Many of these compounds are classified as carcinogenic, or possibly carcinogenic, for humans and, in addition, they can cause long term environmental damage. Despite these drawbacks, they are suitable for wall and/or furniture painting, for the textile treatments, and are widely used in a variety of industrial processes. Unfortunately, they are released into the environment as waste products. As of today, it is not possible to replace VOCs with other compounds, but one can attempt to modify them just before they get disseminated in the atmosphere. The easiest way to achieve that goal is by using combustion reactors. However, they are bulky, require a lot of energy and need to reach high temperatures up to 300°C, or more, to be effective. Atmospheric pressure cold plasmas, in particular Surface Dielectric Barrier Discharge (SDBD), can largely improve the abatement process of VOCs. Indeed, SDBD require much less energy than typical combustion reactors, they occupy much smaller volumes (less than a cubic meter) and the global gas temperature gets down to the order of room temperature. Chemical pollution is not the only problem affecting our living environment, for instance antimicrobial resistance is also becoming an important issue. The antimicrobial and antibacterial drugs have improved our health conditions since they were discovered, but they are becoming less and less effective as a result of their improper use during the last decades. A way to reduce the use of antibiotic can be obtained by eliminating or hindering microbial diffusion in air, such as using particulate filters in ventilation systems. However, the biological agents collected in the filters are not just passive, but get accumulated on the filter surface, thus proliferating during long periods of high relative humidity (>80\%), causing infections at distant places after dissemination. Part of this thesis is devoted to this problem. An innovative use of the SDBD was developed for the abatement of bacteria in air. Its limited volume permits to place the SDBD in contact with the air circulating system of a building, within which one can proceed to the denaturation of the diffusing bacteria by the reactive species produced in the plasma. Finally, the last part of this thesis is devoted to polymeric surfaces modifications through a capacitive coupled low pressure cold plasma. Surface modifications of materials by plasma treatments and depositions have attracted a great deal of interest in the last decades. We can create a nanostructurization over the polymeric treated surfaces that can have different applications, from antifouling in water to antibacterial in air.

Thesis: Ph. D. in Environmental Chemistry, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-110).
.Organic molecules have many important roles in the atmosphere, acting as climate and biogeochemical forcers, and in some cases as toxic pollutants. The lifecycle of atmospheric organic carbon is extremely complex, with reaction in multiple phases (gas, particle, aqueous) and at multiple timescales. The details of the lifecycle chemistry (especially the amount and properties of particles) have important implications for air quality, climate, and human and ecosystem health, and need to be understood better. Much of the chemical complexity and uncertainty lies in the reactions and properties of low-volatility oxidized intermediates that result from the oxidation of volatile organic precursors, and which have received comparatively little study thus far. This thesis describes three projects that link together the entire chain of oxidation (volatile to intermediate to condensed) in an effort to improve our understanding of carbon lifecycle and aerosol production. Laboratory studies of atmospherically relevant aerosol precursors show that the slow oxidation of intermediates is critical to explaining the yield and properties of aerosol under highly oxidized ("aged") conditions, and that the production of organic particles is significantly increased when intermediates are fully oxidized. This aging process is a strong function of molecular structure, and depends on aerosol concentration through the phenomenon of condensational trapping. Further laboratory studies of a series of (poly)cyclic 10 carbon alkanes show that structural effects are largely explained through fragmentation reactions, and that more generally, carbon-carbon bond scission is a ubiquitous and important reaction channel for oxidized intermediates. Finally, direct measurement of oxidized intermediate compounds in field studies shows that these compounds are abundant and important in the ambient atmosphere, with concentrations and properties in between those of volatile and particulate organic compounds. Together with other co-located measurements and complementary techniques, this enables estimates of emission, oxidation, and deposition to be constructed. The results from this thesis can be used to inform more sophisticated models of atmospheric organic carbon cycling, and to improve prediction of organic particulate matter concentrations.
by James Freeman Hunter.
Ph. D. in Environmental Chemistry

The research activity described in the attached dissertation focused on the development, fabrication and characterization of new non-volatile memory elements based on organic technology. During the last few decades, organic materials based devices have attracted considerable interest due to their great potential for future electronic systems. Low fabrication costs, high mechanical flexibility and versatility of the chemical structure, good scalability and easy processing are the unique advantages of organic electronics. As memory devices are essential elements of any kind of electronic system, the development of organic memory devices is fundamental in order to extend the application of organic materials to different electronic circuits. Research on organic electronic memories is currently at a rapid growth stage, since it is recognized that they may be an alternative or supplementary to the conventional memory technologies. Despite considerable progress in the advancement of novel memory technologies in recent years, some challenging tasks still need to be resolved. The Ph.D. research activity of this thesis is related to the still -opened challenges in the organic memories technologies. In particular, it focused mainly on the study, development, fabrication and characterization of new non-volatile organic memory elements based on resistive switching. The activity has been carried out in the frame of the European project “HYbrid organic/inorganic Memory Elements for integration of electronic and photonic Circuitry” (HYMEC), which involved the University of Cagliari during the last three years. The project goal was to realize new hybrid inorganic/organic resistive memory devices with functionality far beyond the state of the art. A complementary activity on transistor-based organic memory devices has been also carried out and described in this thesis. As regards resistive memory devices, the research activity included design, fabrication and testing of a novel non-volatile memory device based on the combination of an air-stable organic semiconductor and metal nanoparticles. This topic required the development of technology and procedures for easy and reliable production of devices as well as the definition of measurement protocols. The proposed structure was thoroughly characterized by morphological techniques, which allowed to interpret the resistive switching mechanisms in terms of formation and rupture of metallic filaments inside the organic layer assisted by the metal NPs. The obtained performances are the best reported so far in literature, and, to our knowledge, the statistics analysis is the largest ever reported for organic-based resistive memories. The developed technology was then successfully applied on flexible plastic substrates. The definition of technological processes for the reliable fabrication of high performance printed organic memory devices was also carried out: this work clearly demonstrates the real possibility of fabricating high performance printed memory elements. A significant effort was also devoted to the development of basic memory/sensor systems entirely fabricated on plastic substrates. The suitability of organic non-volatile memory devices for the detection and the storage of external parameters was demonstrated. The results definitely demonstrated the feasibility of the proposed technology for the fabrication of systems including organic memories for their final application in different industrial processes, including e-textile and smart packaging. As regards transistor memory devices, highly flexible Organic Field-Effect Transistor (OFET)-based memory elements with excellent mechanical stability and high retention time were developed. As main innovation with respect to the state of the art, low voltage operation of the OFET-based memory was investigated. Such an activity was also related to the development of reliable measurement procedures

Les composes carbonyles et BTEX (benzène, toluène, éthylbenzène et xylène) sont deux groupes importants de composés organiques volatils (COV) présents dans l'atmosphère. Ils ont une contribution significative à la formation d'oxydants tels que l'ozone, PAN et d'autres photo-oxydants dans la troposphère. En outre, ils ont des effets néfastes sur la santé humaine. Dans ce travail, les concentrations atmosphériques de carbonyles et d’hydrocarbures aromatiques ont été mesurées et quantifiées en utilisant des techniques HPLC et GC-MS sur un site de mesure semi-urbain à Orléans (ICARE, France), de juin 2010 à août 2011. D’autres mesures ont été conduites à Pékin (CAS-RCEES, Chine) du 6 au 28 Juin 2013 en utilisant les mêmes techniques expérimentales. Les résultats obtenus dans ces deux sites sont présentés, comparés et discutés
Carbonyls and BTEX (benzene, toluene, ethyl-benzene and xylene) are two important groups of Volatile Organic Compounds (VOCs) present in the atmosphere. They have a significant contribution to the formation of oxidants such as ozone, PAN and other photooxidants in the troposphere. In addition, they have adverse effects on human health. In this work, atmospheric concentrations of carbonyls and aromatic hydrocarbons were measured and quantified using GC-MS and HPLC techniques at a semi-urban site in Orleans (ICARE, France), from June 2010 to August 2011. Urban ambient air sampling was also performed in 6-28th June 2013 in Beijing (RCEES-CAS, China). It has been conducted in order to compare the measured concentrations of the investigated species in two different sites using the same analytical techniques. All results are presented and discussed

La compréhension de la formation des aérosols organiques secondaires (AOS) reste lacunaire, notamment lors de l’ozonolyse de composés organiques volatils (COV) insaturés. La mesure de composés de faible volatilité participant à la génération des AOS est un défi auquel la communauté scientifique tente de répondre. Un des objectifs de ce travail de thèse était l’installation et l’emploi d’un système d’échantillonnage et de mesure de la composition chimique de l’aérosol par spectrométrie de masse à ionisation chimique (FIGAERO-CI-ToF-MS). Cet instrument a été utilisé dans le cadre de l’ozonolyse de COV insaturés dans la chambre de simulation atmosphérique HELIOS et a permis d’évaluer les conditions de formation d’acides carboxyliques et de composés organosoufrés. Les voies de formation spécifiques des organosulfates (OS) ont par ailleurs été étudiées en injectant des particules d’ensemencement acidifiées. Cette étude a confirmé la faible efficacité de l’estérification des groupements hydroxyles. A l’inverse, la formation d’OS par ouverture de cycle époxyde est plus efficace et augmente à pH plus acide. Par ailleurs, l’augmentation de l’humidité relative a un impact positif sur la génération d’acides carboxyliques en phase particulaire.Un deuxième objectif était la caractérisation d’un système de collecte de l’aérosol et de mesure de sa composition chimique, couplé à un spectromètre de masse à transfert de protons (CHARON-PTR-ToF-MS). La mesure de la fragmentation de 26 composés purs en phase particulaire a permis le développement d’une procédure corrective tenant compte du phénomène de fragmentation. Cette procédure a été appliquée à la mesure d’AOS générés par l’ozonolyse de COV biogéniques en réacteur a écoulement. La volatilité de l’aérosol produit a été estimée par l’installation d’un tube thermodénudeur. La prise en compte de la fragmentation a grandement amélioré l’accord entre la mesure de la volatilité et son calcul par plusieurs équations paramétriques
The understanding of secondary organic aerosols (SOA) is still incomplete, especially from the ozonolysis of unsaturated volatile organic compounds (VOC). The measurement of low volatility compounds involved in SOA formation is a challenge that the scientific community attempts to address. One of the objectives of this thesis work was the installation and use of a system for sampling and measuring the chemical composition of the aerosol by chemical ionization mass spectrometry (FIGAERO-CI-ToF-MS). This instrument has been used in the ozonolysis of unsaturated VOCs in the atmospheric simulation chamber HELIOS and the conditions for the formation of carboxylic acids and organosulfur compounds has been evaluated. The specific formation pathways of organosulfates (OS) have in addition been studied by injecting acidified seed particles. This study confirmed the low efficiency of the esterification of hydroxyl groups. Conversely, OS formation by epoxide ring opening is more efficient and increases with more acidic pH. In addition, the increase in relative humidity has a positive impact on the generation of carboxylic acids in the particulate phase.A second objective was the characterization of a system coupled to a proton transfer mass spectrometer (CHARON-PTR-ToF-MS) for collecting aerosols and measuring its chemical composition. The measurement of the fragmentation of 26 pure compounds in particulate phase allowed the development of a corrective procedure taking into account fragmentation process. This procedure was applied to the measurement of SOA generated by the ozonolysis of biogenic VOCs in an aerosol flow reactor. The volatility of the aerosol has been estimated using a thermodenuder installed downstream of the reactor. Taking into account fragmentation has greatly improved the agreement between the measured and the calculated volatility by several parametric equations

Les composés organiques carbonylés et les BTEX (Benzène, Toluène, Éthylbenzène et Xylènes) représentent une classe importante de composés organiques volatils dans l’atmosphère. Ils sont émis par des sources anthropogénique et biogéniques. Leur dégradation atmosphérique conduit à la formation d’ozone, de phooxidants et d’aérosols organiques affectant ainsi la qualité de l’air aux échelles locales et régionales ainsi que la santé humaine. Il est donc important de mesurer leurs concentrations et évaluer leur devenir atmosphérique. Dans la présente thèse, nous avons conduit une étude systématique qui a permis de mesurer les concentrations de ces composés et identifier leurs sources à Pékin (Juillet 2008-Août 2010) et évaluer l’importance des caractéristiques météo. Nous avons aussi mené des études sur la dégradation atmosphérique de trois formates (isoproyle, isobutyle et n-propyle) en utilisant la chambre de simulation atmosphérique d’ICARE (CNRS, Orléans)
Carbonyls and BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) represent an important class of VOCs (volatile organic compounds) in the atmosphere. They are emitted into the atmosphere through anthropogenic and biogenic sources. Their atmospheric degradation leads to the formation of ozone, photooxidants and organic aerosols affecting the air quality at the local and regional scales and human health. It is, hence, of importance to measure their atmospheric concentrations and investigate their fate. In the present thesis, we have conducted a systematic measurement study of carbonyls and BTEX in Beijing during the period of Jul 2008-Aug 2010 in order to evaluate their ambient levels, possible sources and the influence of characteristic weather conditions. In a separate work, we performed a series of experimental studies on the OH-initiated oxidation of isopropyl formate, isobutyl formate, and n-propyl isobutyrate using the ICARE-CNRS (Orleans) simulation chamber from which we derived the product yields. The data obtained are presented and discussed

Aerosols are either emitted directly into the atmosphere or are generated in the atmosphere; the latter process forms secondary organic aerosol (SOA). One of the important sources for SOA is the oxidation of volatile organic compounds (VOCs) by OH radicals, NOx, and O3. Aerosol can be visualized as suspended solid or liquid particle which is in equilibrium with surrounding gases. The products of SOA formation is a mixture of semi volatile organic compounds and a fraction of the products are condensable under atmospheric conditions. The condensable portion of aerosol is called particulate matter (PM) and these suspended particles can range in diameter from a few nanometers to microns. PM can impact climate through direct and indirect radiative forcing and can degrade air quality by reducing visibility and causing detrimental health effects. SOA can also form indoors, which also contributes to the health risk of PM. The severe impact of PM on human health and climate drives the scientific community to investigate the volatile organic compounds (VOCs) and their potential to form SOA, as well as the factors that alter the efficiency of SOA generation and the type of products. In a similar pursuit, the focus of this dissertation is the investigation of the SOA precursors that are emitted from trees and how they vary as a function of insect infestation. Also, the role of mixtures of VOCs as SOA precursors are investigated; commercial and lab made VOC mixtures are studied for SOA generation, product analysis, and absorption characteristics of aged SOA. Chapter 1 introduces PM, VOCs present in atmosphere, SOA generation, and speciation of products generated from the ozonolysis of VOCs. The impact of PM on human health and climate are summarized. A literature survey on the VOCs that are precursors to SOA and present in the outdoor and indoor environment is presented along with factors that may lead to variability in amount of VOCs. SOA generation from direct plant emissions and consumer products is surveyed. These studies show that VOC oxidation generate SOA which is important in the atmosphere due to climate and health effects and indoors due to health effects. A summary of SOA phase partitioning theories, the reaction mechanism for the formation of products from ozonolysis of the dominant biogenic SOA precursors (monoterpenes), and the factors that affect SOA generation is presented. Chapter 2 summarizes the results obtained from a field study assessing the impact of bark beetle infestation on SOA precursor emissions from forests in the Western United States. Samples of VOCs were collected by our collaborators from healthy and bark beetle infested trees using scent traps. We solvent extracted and analyzed by gas chromatography/mass spectrometry (GC/MS) nearly four hundred scent traps. An increase in the total and the individual VOCs emitted by infested trees was measured. A statistical analysis shows significant differences between the emissions from infested and healthy trees. A perspective is provided on potential impact of bark beetle infestation on regional SOA. The majority of the laboratory experiments for SOA generation have focused on individual VOCs as the single SOA precursor. However, as demonstrated in Chapter 2 for example, in a real environment multiple VOCs co-exist. Multiple SOA precursors undergo concurrent oxidation reactions, and it is not known if the products from concurrent oxidation of multiple precursors are the same as the sum of the products from individual SOA precursors. Mass closure analysis of field samples show that a significant fraction of the chemical identity of organic PM is unknown, but the chemistry impacts the toxicity of PM. Hence, it is important to understand SOA formation from realistic SOA mixtures. Chapter 3 describes the results of the SOA generation by ozonolysis of limonene and VOC mixtures containing limonene. We use an additive approach for building a surrogate VOC mixture close in composition to a commercially-available mixture. The yield of PM as a function of VOC precursor mixture was measured with respect to VOC composition using smog chamber SOA generation and scanning mobility particle sizing. PM in the chamber was collected onto filters and extracted, and the individual products of SOA were identified and quantified by GC/MS. The condensed-phase SOA products generated during these experiments for different VOC mixtures are compared. In Chapter 4, condensed-phase products sampled from SOA generated by the ozonolysis of α pinene and VOC mixtures containing α pinene, including two fir needle essential oils, are studied by extracting filter samples and analyzing the extracts by GC/MS. The products generated from VOC mixtures are characteristic of the most dominant VOC present in the mixture i.e. either limonene or α pinene. Some mixtures show the generation of new products which are not observed for corresponding individual VOC ozonolysis and hence can be used as marker for the corresponding VOC mixture. The distribution of α-pinene SOA products changes as the composition of the SOA precursor mixture changes. In Chapter 5, the UV visible absorption characteristics of ammonium ion aged SOA are discussed. Ammonium ion aging of aerosol leads impacts the radiative properties of aerosol and has the potential to impact aerosol's role in climate change. Filter samples containing SOA generated from two mixtures with different dominant monoterpenes (α-pinene-based Siberian fir needle oil and a limonene-based air freshener) were extracted. The absorption coefficients of the extracts were measured as a function of ammonium ion aging time using UV-visible absorption spectrometry. The conclusions from all above chapters are summarized in Chapter 6.

La perméation de vapeur, procédé de séparation utilisant des membranes denses constitue une alternative attrayante pour épurer les effluents gazeux faiblement chargés en composés organiques volatiles (COV). Son principe repose sur l'extraction préférentielle de composés organiques, qui présentent une meilleure affinité pour le polymère, le transfert de matière étant rendu possible par une différence de pression imposée de part et d'autre de la membrane. Une cinquantaine d'unités industrielles sont déjà en fonction principalement pour traiter des hydrocarbures mais les connaissances théoriques et la compréhension des phénomènes permettant un dimensionnement rationnel sont encore insuffisantes. L’objectif de ce travail est d'étudier l'extraction de solvants oxygénés (acétone et acétate de méthyle) de l'air à l'aide de membranes de polydiméthylsiloxane (PDMS). La compréhension du mécanisme global de transfert à travers la membrane imposait une étude approfondie de la sorption, comprenant une analyse des mesures expérimentales et une tentative de modélisation (binaire et ternaire) à l'aide de modèles existants. Une méthode récemment développée, utilisant la chromatographie en phase gazeuse pour évaluer les coefficients de sorption, à par ailleurs été expérimentée. D’autre part, le développement d'un nouveau test de cohérence thermodynamique applicable aux équilibres polymère réticule / solvant a permis la validation des résultats de sorption obtenus. Différents paramètres opératoires intervenant sur les performances du procédé ont ensuite été étudiés : le type de membrane, la nature du COV, la pression et la température. Finalement, la modélisation du procédé a été abordée : les modèles couramment proposés et une nouvelle approche ont été comparés et confrontés aux résultats expérimentaux obtenus. Les modèles ont enfin été mis à profit pour dimensionner un module de perméation, de manière simplifiée.

Polycyclic aromatic hydrocarbons (PAHs) are an important class of volatile organic compounds (VOCs) which pose enormous health and environmental threats. This thesis investigates different catalyst formulations for the complete oxidation of naphthalene (Np). a model PAH. Low loadings of vanadium added during the impregnation step of catalyst preparation were found to enhance the naphthalene oxidation activity of Pd-alumina and Pt- alumina catalysts while higher loadings were detrimental to the catalysts' performance. The promotional effect has been attributed to the presence of a low concentration of a particular type of vanadium species which fosters the redox behaviour of the binary system (Pd/V or Pt/V) coupled with the change in the active metal (Pd or Pt) particle size (Pd or Pt dispersion). The presence of high concentrations of crystalline V2O5 species has been suggested to account for the lower activity observed for Pd/V and Pt/V catalysts with vanadium loadings in the range of 6 - 12% and 1 - 12 % respectively. It is postulated that the mechanism of naphthalene oxidation over Pd/V differs from the mechanism of oxidation over Pt/V catalysts. The nature of support material was established to be crucial for the activity of Pt- supported catalysts for naphthalene oxidation. The Pt dispersion, metal-support interaction (MSI) and oxidation state of Pt varied as a function of the nature of support and hence resulted in differences in the Np oxidation efficiency of five Pt- supported catalysts with equal Pt loading but different supports. Low Pt dispersion (high Pt particle size), weak MSI and metallic state of Pt favoured Np oxidation. Si02 proved to be the best amongst five Pt supports investigated for Np oxidation. A variation in the preparation method and preparation conditions of ceria affected the surface area, crystallite size, oxygen defect concentration, morphology and surface reducibility of the ceria catalyst and hence the Np oxidation activity. High surface area, small crystallite size, and high oxygen defect concentration of Ce02 favoured the activity of the catalyst for Np oxidation. The best preparation methods in this study were found to be homogeneous precipitation with urea (UR) and precipitation with the carbonate (CR). Optimum preparation conditions for ceria (UR) were established and a highly active nano-crystalline ceria catalyst for Np oxidation was derived. The addition of low and high loadings of Pt during the precipitation of this ceria (UR) catalyst resulted in less active naphthalene oxidation catalysts. The drop in activity of ceria with Pt doping has been attributed to a strong metal support interaction between Pt and ceria which limits the ease at which lattice oxygen is consumed in the Mars-Van krevelen redox cycle.

In this study volatile organic compounds (VOCs) emitted during carpet installations employing water-based adhesives were characterized. The potential impacts of 4 adhesives on indoor air quality were evaluated. Headspace sampling and analysis by gas chromatography/mass spectrometry were used to qualitate VOC emissions. Adhesives and carpet/adhesive composite samples were prepared for quantitative analysis of VOC emissions by gas chromatography with flame ionization detection. Volatiles were concentrated using a monitoring device and collected on charcoal adsorption tubes. Sampling intervals ranged from 30 minutes to 21 days. The adhesives emitted primarily aromatic, alicyclic and aliphatic compounds as toluene, m-xylene, 1,2-dimethylcyclohexane, alpha-pinene, 2-methylheptane, octane, nonane, decane and undecane. Emission profiles depended on performance characteristics and manufacturer. A carpet boundary layer slowed VOC decay by acting as a sink. Potential overexposure within 24 hours to specific and total VOCs was indicated for one of the adhesives. This study suggests that water-based carpet adhesives are a potential source of indoor air pollutants.

Polypyrol (PPy) je heterocyklický vodivý polymer s chemickou strukturou založenou na existenci systému konjugovaných elektronů mezi střídajícími se jednoduchými a dvojnými vazbami. Díky svým vynikajícím vlastnostem jako je dobrá elektrická vodivost, relativně vysoká stabilita prostředí a zároveň i jednoduchost a variabilita metod jeho přípravy, přilákal tento polymer pozornost mnoha vědců z různých vědních disciplín. Cílem výzkumu v této dizertační práci byla studie senzorického chování PPy. Za tímto účelem byla ověřena účinnost nanostruktur PPy při detekci vybraných „vysoce důležitých molekul plynů“ včetně acetonu, amoniaku, etanolu, etylenu a toluenu. V této práci byl připraven PPy ve formě nanotyčinek (NRs) pomocí elektrochemické syntézy a také ve formě nanočástic (NPs) chemickou cestou. Dále byly připraveny modifikované PPy struktury, a to funkcionalizací PPy NPs katalytickými částicemi zlata (Au), stříbra (Ag) a teluridu kademnatého (CdTe). Pro charakterizaci morfologie, složení a struktury připravených materiálů bylo použito několik komplementárních analytických (mikroskopických i spektroskopických) technik. Navíc byly využity techniky jako Ramanova a rentgenová fotoelektronová spektroskopie (XPS) pro in-situ test detekce plynů, které potvrdily potenciál připraveného materiálu, tedy PPy NRs i PPy NPs, pro využití v senzorech plynů. Za účelem výroby senzoru plynů byl připravený PPy materiál integrován do dvou typů převodníkových platforem: chemorezistivní a na bázi povrchové akustické vlny v tzv. Love módu (L-SAW). Test detekce plynů pro chemorezistivní senzory s PPy NRs ukázal pouze zanedbatelnou odpověď těchto senzorů pro oxid dusičitý a amoniak z důvodu jejich komplikované architektury. Změření odzevy tvou typú chemorezistivních senzorů-nemodifikovaného i modifikovaného PPy NPs nebylo možné z dúvodu extrémně vysoké odporu v řádu G. Nicméně multivodivé L-SAW senzory založené na holých PPy NPs či PPy NPs modifikovaných Au či Ag NPs a nebo CdTe kvantovými tečkami (QDs) vykazovaly odezvu pro nízké koncentrace všech testovaných velmi důležitých molekul plynů při pokojové teplotě (RT). Obecně měly L-SAW senzory s modifikovanou citlivou vrstvou vyšší citlivost než senzory s nemodifikovanou PPy citlivou vrstvou. Účinnost L-SAW senzoru primárně závisí na pracovní frekvenci a na výběru citlivé vrstvy v aktivní oblasti senzoru. Z otestovaných typů vrstev senzoru vuči jednotlivým plynům, modifikovaná PPy NPs s Ag NPs i Au NPs se javí jako nejlepší varianta pro detekci acetonu. Připravené L-SAW senzory na bázi PPy jsou jednoduchá a cenově přijatelná zařízení s vylepšenými detekčními vlastnostmi jako je vysoká senzitivita a nízký limit detekce (LOD), což je řadí mezi potenciální kandidáty v budoucích systémech pro kontrolu kvality vzduchu, potravin a rovněž pro diagnostiku nemocí z dechu.

Abstract This thesis describes efforts made on the development of an existing catalytic incinerator. The development work, called process characterization, consists of four general parts. These are the development of measurement methodology, the studying of construction materials, the selection of suitable catalysts and the testing of the effects of process operation conditions. The two application areas for catalytic incineration considered in this thesis are solvent emission abatement (VOC, volatile organic compounds) and chip bin emission abatement (SVOC, sulphur-containing volatile organic compounds). As a baseline, the process characterization is started with the development of measurement methodology. In general, the methodology will decrease costs and simplify the carrying out of the actual measurements and thereby make the measurement time more effective. In the methodology it is proposed that continuous total concentration measurement should be used in connection with qualitative sampling to obtain reliable measurement data. The selection of suitable construction materials for the application is very important. As shown in this thesis, the end conversions in solvent emission abatement may even be improved through the selection of the proper construction materials. In chip bin emission abatement, the problem arises from corrosive oxidation products that set limits on the construction materials used as well as on oxidation conditions. Catalyst selection is based on the following catalytic properties: activity, selectivity and durability. These catalytic properties are studied either at the laboratory or on an industrial scale. The catalytic materials tested are Pt, Pd, Pt-Pd, Cu-Mn oxides, MnO2-MgO, CuxMg(1-x)Cr2O4 and CuxCr2O4. The most important selection criteria in solvent emission abatement are proposed to be activity and selectivity. In the case of chip bin-SVOC-abatement, these are selectivity and durability. Based on these criteria, catalysts containing Cu-Mn oxides and Pt were demonstrated to be the best catalysts in VOC oxidation, and catalyst containing MnO2-MgO was shown to be best catalyst in SVOC oxidation. A study on the effect of process operation parameters (temperature, concentration and gas hourly space velocity (GHSV)) and moisture was carried out with the aid of factorial design. In VOC (n-butyl acetate) oxidation, the most influential process parameter was GHSV, which decreased the end conversion when it was increased. In SVOC (DMDS) oxidation, the effect of temperature was most significant. The end conversions increased as the temperature increased. Moisture slightly decreased the formation of by-products in n-butyl acetate oxidation. In DMDS oxidation, moisture slightly increased the end conversions at a lower temperature level (300°C). At the end of the thesis, these process parameters are also discussed from the standpoint of the catalysts' activity, selectivity and durability. Finally, proposals for process improvements are suggested.

Metal-organic frameworks (MOFs) present potential for various applications such as gas sorption, gas storage, sensing, drug delivery, and catalysis. This attracts researchers to design and synthesize MOFs that can respond to a specific application. In this thesis, mixed ligands 34pba and 44pba ligands (34pba = 3-(4-pyridyl)benzoate, and 44pba = 4-(4-pyridyl)benzoate) and Co2+ metal salts were used to synthesize porous MOFs {[Co(34pba)(44pba)]·DMF}n (1) and {[Co(34pba)(44pba)]·(C3H6O)}n (2), with DMF = N,N'-dimethylformamide and C3H6O = acetone through solvothermal reaction. These two relate to each other through hinge-like expansion or contraction of the guest-accessible void. The use of Zn2+ as a metal ion led to an isostructural MOFs [Zn(34pba)(44pba)]·DMF}n (3) of 1. Using 34pba as a single ligand and Cu2+ as the metal ion led to the formation of a 2D [(Cu(34pba)2]·DMF) (4) while a little variation of solvent mixture resulted in a 3D {[CuCl2(34pba)2]∙solvent}n (7) structures. The functionalized ligands 44paba and 34paba (34paba = 3-(pyridyn-4-ylmethyl)aminobenzoate, 44paba = 4-(pyridyn-4- ylmethyl)aminobenzoate) were used with Cu2+ centre to prepare [Cu(44paba)·(H2O)·(DMF)]n (5) and {[Cu3(34paba)5(H2O)2]·(DMF)2}n (6), both of which are 1D structures. The activated MOFs 1d and 3d from (1 and 2) were used for the adsorption of volatile organic compounds (VOCs) and gases. In all tested guest molecules, there was higher sorption capacity in 1d which could be attributed to some gate opening process occurring which does not occur in 3d. Some effects responding to the sorption such as the change of colour in 1d were characterized. This colour change may be associated with the d-d, metal to ligand charge transfer, or π to π* transitions in coordination complex. Crystal structures and their stability, sorption properties and selectivity were characterized by single crystal X-ray diffraction, thermogravimetric analysis, differential scanning, hot stage microscopy, powder X-ray diffraction, infrared spectroscopy, and proton viii nuclear magnetic resonance (1H NMR) analysis. This thesis also reports the effect of methanol on discrete complexes of cis-dichloro-bis(ethylenediamine)cobalt(III) chloride (Coen) that led to the formation of a new crystal structure upon the removal of the water of hydration. The lattice energies calculated prove that Coen is more stable to allow a quick reversible sorption.

This thesis mainly described the development of studying the behavior and secondary organic aerosol formation from semi-volatile organic compounds (SVOCs). SVOCs comprises a significant fraction of the organic mass in particulate matter (PM), which has shown important impacts on human health and also influences on Earth’s climate. SVOCs are thought to play essential roles in the formation of SOA, chemical aging and mixing processes. Smog chambers have been extensively used to study SOA formation, chemical reaction and physical properties. The interaction between SVOC vapor with Teflon chamber wall and suspended particles is a key factor influencing organic aerosol formations and behaviors in chamber experiments. We observed that pinanediol (PD) showed a large chamber wall deposition and reached a steady concentration, only around 14% of mass left in the gas phase. But we did not observe the release of PD from the chamber walls during isothermal dilution of the chamber with fresh air at 22 oC, which indicated there was no PD released from the chamber walls during the SOA formation. This clearly shows the vapor loss of SVOC precursors need to be considered when studying their SOA formation. The average carbon oxidation states the SOA from PD were calculated as around -0.7, which were similar to the value observed in CLOUD. Our data are consistent with ~10% of the SOA with low volatility that could drive new particle formation. It is challenging to measure SVOC vapor concentrations and properties. A new approach is discussed in this thesis, studying SVOC vapors from measuring the particles. The SVOCs coated particles sustained the SVOCs in the gas phase at or near their saturation concentration. The mass loss of SVOCs from the suspended particles thus reflects SVOCs vapor wall loss. Our results show the vapor wall loss rate of SVOC is consistently proportional to the SVOC vapor concentrations. We observed PEG400 seeds can sorb semi-volatile α-pinene SOA vapors. This allows us to trap semi-volatile α-pinene SOA into PEG400 seeds and then analyze their compositions and properties through measuring particles. PEG400 is liquid, water-soluble, nearly non-volatile, good solvent for SOA and relative stable during the oxidation with OH radicals and ozone. It can also be easily separated from the SOA mass spectrum with the unique fragment C4H9O2+ at m/z=89. The results demonstrated that SOA prepared from α-pinene reacted with OH produced more semi-volatile SOA vapors comparing to α-pinene ozonolysis. More semi-volatile SOA vapors were observed in the gas phase with higher SOA loadings. With well-built particle measurement methods, we may get more knowledge on the SVOC vapors.

The central aim of this thesis is to support the efforts to counteract certain environmental problems caused by emissions of volatile organic compounds. The purpose of this work was (1) to develop a method to establish the amount of emitted substances from dryers, (2) to determine the effect of drying medium temperature and end moisture content of the processed material on emissions of monoterpenes and other hydrocarbons, (3) to examine the emissions of monoterpenes during production of pellets, and (4) to examine the natural emissions from forests with an eye to implications for modelling. The measurement method (1) resolves the difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapour to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted volatile organic compounds and to determine the moisture content of the drying medium. The method as used in this paper has an uncertainty of 13% using a 95% confidence interval. Emissions from a spouted bed (2) in continuous operation drying Norway spruce sawdust at temperatures of 140°C, 170°C or 200°C was analysed with FID and GC-MS. When the sawdust end moisture content was reduced below 10%wb, emissions of terpenes and volatile organic compounds per oven dry weight increased rapidly. Increased temperature of the drying medium increased the amounts of emitted monoterpenes when sawdust moisture content was below the fibre saturation point. Examination of sawdust and wood pellets from different pellets producers (3) revealed that most of the terpene emissions happened during the drying step, with rotary dryers causing higher emissions than steam dryers. Almost all of the volatile terpenes remaining in wood after drying were released during pelleting. When sawdust with higher moisture content was used in the pellets press, the terpene emissions were increased. Terpenes emitted naturally from vegetation can have an adverse environmental impact. Factors affecting terpene emissions from tree species in Sweden were reviewed (4). Models for prediction of terpene fluxes should include not only temperature but also light intensity, seasonal variation, and a base level of herbivory and insect predation. Prediction of high concentrations of ambient terpenes demand sufficient resolution to capture emission peaks e.g. those caused by bud break.

Les composés organiques volatils oxygénés (COVO), principalement émis par des sources biogènes, jouent un rôle majeur dans la chimie de l'atmosphère, le changement climatique, l'environnement et la santé. Il a été récemment démontré que ces émissions augmentent en cas de stress biotique et/ou abiotique. Les COVO biogéniques peuvent subir une variété de réactions, tant chimiques que photolytiques, et ils sont impliqués dans la formation d'Aérosols Organiques Secondaires (AOS). Ces composés ont été détectés dans diverses régions, mais il y a très peu d’informations sur leurs processus de dégradation sous conditions troposphériques. La compréhension des mécanismes d'oxydation de ces espèces est d'un intérêt fondamental et fournit des données cruciales pour les modèles atmosphériques qui sont utilisés par les responsables politiques pour formuler et décider des stratégies d'amélioration de la qualité de l'air. Cette thèse vise à améliorer les connaissances actuelles sur le comportement de ces COVO, pour une meilleure compréhension de leur impact sur la chimie atmosphérique. Dans ce travail, nous avons présenté une étude détaillée de la dégradation atmosphérique des aldéhydes insaturés en C5-C7 et des alcools insaturés en C5-C8 par ozone, l’atome Cl et le radical OH. Les principaux objectifs étaient de mieux comprendre le mécanisme de réaction et de mettre en évidence leur potentiel à former des AOS. Pour atteindre ces objectifs, nous nous sommes concentrés sur quatres volets : (i) détermination du spectre IR et UV des aldéhydes insaturés en C5-C7, (ii) détermination de la constante de vitesse pour les systèmes COVO + Oxydant étudiés à température ambiante, (iii) identification et quantification des produits en phase gazeuse, (iv) détermination des rendements en AOS. Les études sur les produits ont été menées avec et sans ajout d'un piégeur des radicaux OH. Les expériences ont été réalisées dans huit réacteurs différents, statiques (chambres) ou dynamiques (flux), et diverses techniques analytiques ont été utilisées pour étudier les produits de réaction (FTIR, GC-FID/MS, SPME-GC/MS, HPLC, PTR-ToF-MS, SIFT-MS, PLP-LIF) et la formation de SOA (SMPS, FMPS)
Oxygenated Volatile Organic Compounds (OVOCs), mainly released from biogenic sources, play a major role in atmospheric chemistry, climate change, environment, and health. These emissions have been recently shown to increase in the case of biotic and/or abiotic stresses. Biogenic OVOCs may undergo a wide variety of reactions, both chemical and photolytic, and they contribute in the formation of Secondary Organic Aerosols (SOAs). These compounds have been detected in various areas, but little is known about their degradation processes under tropospheric conditions. Understanding the oxidation mechanisms of these species is of fundamental interest and yields crucial data for atmospheric models used by policymakers in formulating and deciding strategies for improving air quality. This dissertation aims to improve the current knowledge of those OVOCs behaviors to better understand their impact on atmospheric chemistry. This work reports a detailed study of the atmospheric degradation of C5-C7 unsaturated aldehydes and C5-C8 unsaturated alcohols by ozone, Cl atom, and OH radical. The main objectives were to better understand the reaction mechanism and to feature the SOA formation potential. To achieve these objectives, we focused on four topics: (i) determination of IR and UV spectrum of C5-C7 unsaturated aldehydes, (ii) determination of the rate constant for the studied OVOCs + Oxidant at room temperature, (iii) identification and quantification of the gas-phase products, (iv) determination of the SOA yields. The product studies were investigated both with and without adding an OH radical scavenger. Experiments were performed in eight different static (chambers) or dynamic (flow) reactors, and various analytical techniques were used to investigate the reaction products (FTIR, GC-FID/MS, SPME-GC/MS, HPLC, PTR-ToF-MS, SIFT-MS, PLP-LIF) and SOA formation (SMPS, FMPS)

Ce travail est une contribution à la compréhension des performances de matériaux hybrides poreux de type MOFs pour le captage de benzène, dans le cadre de la lutte contre les émissions de Composés Organiques Volatils (COVs) à partir de procédés basés sur l'adsorption d'effluents gazeux. Dans ce but, nous avons couplé diverses techniques expérimentales (spectroscopie d'impédance complexe, diffraction des rayons X, manométrie d'adsorption, …) à des simulations moléculaires (calculs basés sur la Théorie de la Fonctionnelle de la Densité, Monte Carlo ou Dynamique Moléculaire) pour étudier ces matériaux en termes de capacité et de mécanisme d'adsorption. Différentes familles de MOFs ont été sélectionnées afin d'analyser l'impact de diverses caractéristiques de ces matériaux, comme la flexibilité du réseau, la présence de cations extra-réseau et la nature chimique des ligands organiques, sur leurs propriétés d'adsorption de benzène. Par ailleurs, l'eau étant souvent considérée comme un facteur limitant lors de l'adsorption sélective d'une espèce à partir d'effluents gazeux chargés d'humidité, nous avons également envisagé l'étude de cet adsorbat seul, avant d'explorer la co-adsorption de mélanges benzène/eau dans des proportions différentes. Une rationalisation des données nous a permis de conclure que certains des matériaux explorés présentent une sélectivité benzène/eau intéressante pour envisager leur utilisation potentielle dans le cadre du captage de traces
The Metal Organic Frameworks (MOFs), a recent class of hybrid porous solids, appears as valuable candidates for various applications related to their sorption abilities. The optimization of their performances requires a control of the parameters that govern the adsorption process, including the confined species/MOF interactions and the synergic dynamics of the system. In this context, experimental tools (Complex Impedance Spectroscopy, X Ray Diffraction, volumetric adsorption…) were combined with molecular simulations (Density Functional Theory, Monte Carlo and Molecular Dynamics calculations) to explore the benzene adsorption of MOFs in terms of capacity and microscopic mechanism. Different series of MOFs were selected to address the impact of various features, including the lattice flexibility, the presence of extra-framework cations and the ligand functionalization, on their adsorption performances. Benzene and water were considered as adsorbents separately, before exploring the co-adsorption of various benzene/water mixtures. The rationalization of the data allowed us to understand why some of the selected solids, showing interesting benzene/water selectivity, are likely to be used for the capture of benzene traces in humid conditions

A l’échelle globale, les forêts sont parmi les écosystèmes les plus émetteurs de composés organiques volatils (COV). Une fois émis dans l’atmosphère, ces COV vont rapidement être oxydés en composés oxygénés. Selon leur volatilité et leur réactivité, ces produits d’oxydation pourront eux-mêmes être oxydés et rester soit en phase gazeuse et/ou être transférés dans la phase particulaire pour former des aérosols organiques secondaires (AOS). Cette thèse a eu pour objet principal de mieux caractériser les COV biogéniques (COVBs) en forêt des Landes, leurs concentrations et plus particulièrement leur réactivité avec les différents oxydants atmosphériques (i.e. le radical hydroxyle (OH), l’ozone (O3) et le radical nitrate (NO3)), afin d’identifier les principaux précurseurs de la formation des AOS biogéniques, au sein d’une forêt de pins maritimes. Le développement d'une nouvelle méthodologie chromatographique en phase gazeuse a permis la mesure spéciée et en ligne de 20 COVB comprenant l’isoprène, l’α- et le β-pinène, le 2 et le Δ3- carène, l’α- et le γ-terpinène, le linalool, le camphène, etc. Cette analyseur ainsi que d’autres instruments permettant la mesure de gaz traces et d’aérosols ont été utilisés au cours de l’été 2017 dans le cadre de la campagne intensive LANDEX, dans l’une des plus grandes forêts monospécifique d’Europe (>95% Pinus pinaster). Une analyse en composante principale des données météorologiques et des mesures en COVB, obtenues pendant la campagne a permis de montrer que les concentrations en COVB étaient principalement dépendantes de leurs émissions, de la température, de l'irradiation solaire et de la stabilité atmosphérique. L’analyse de la réactivité des COVB avec les principaux oxydants atmosphériques a permis de montrer le contraste entre le jour, où elle est principalement liée au radical OH et la nuit, où les processus d'ozonolyse dominent. Enfin, il a été mis en évidence que l’ozonolyse du β-caryophyllène, de l’α-pinène, du myrcène, et du linalol et l’oxydation de l’isoprène par le radical OH, étaient les principales sources de composés oxygénés, précurseurs d'AOS, en forêt des Landes
At the global scale, forests are the largest emitters of VOCs. Once released into the atmosphere, VOCs will be fastly oxidized to oxygenated compounds. Depending on their volatility and reactivity, these oxidation products may themselves be re-oxidized, remain in the gas phase and/or be transferred to the particulate phase to form secondary organic aerosols (SOAs). This thesis aimed to better characterize biogenic VOC concentrations (BVOCs) and more especially their reactivity with atmospheric oxidants (i.e. the hydroxyl radical (OH), ozone (O3) and the nitrate radical (NO3)), in order to identify the main precursors of SOA formation within a maritime pine forest. The metrological development of a gas chromatographic analyzer has made possible the online and specified measurement of 20 BVOCs including isoprene, α- and β-pinene, 2 and Δ3-carene, α- and γ-terpinene, linalool, camphene, etc. This analyzer and some other instruments for the measurement of trace gases and aerosols were used during the summer of 2017 as part of the LANDEX intensive campaign in one of the largest pine forests in Europe (> 95% Pinus pinaster) located in the southwest of France. A principal component analysis of meteorological data and BVOC measurements showed that BVOC concentrations were mainly dependent on their emissions, the ambient temperature, the solar irradiation and the atmospheric stability. The analysis of the reactivity of the identified VOCs with the main atmospheric oxidants has helped to show the contrast between processes involving OH radical during daytime and ozonolysis at night. Finally, it was determined that the ozonolysis of β-caryophyllene, α-pinene, myrcene, and linalool, and the OH initiated oxidation of isoprene were the main sources of oxidation products, as SOA precursors, within the Landes forest

Anthropogenic volatile organic compounds (VOCs) and semi-volatile organic (SVOCs) compounds are atmospheric pollutants contributing to the photochemical formation of tropospheric ozone. We combined adsorption and UV photolysis techniques for the removal and degradation of selected VOCs and SVOCs. For adsorption, we synthesized magnetite nanoparticles, a naturally occurring material, to avoid unknown detrimental impacts associated with new materials, as was the case with chlorofluorcarbons. The removal efficiency with magnetite was up to 98 % for aromatics, and 30% for light alkanes. Magnetite nanoparticles were regenerated, characterized (TEM, XRD, BET), and reused with no decrease in reported removal efficiencies. Photolysis alone removed up to 30% of aromatics, and less than 20% of light alkanes. The combination of adsorption, and photolysis did not improve the removal efficiency. Adsorption was attributed to London dispersion interactions for light alkanes, and to acid-base properties for aromatics. Reductions by photolysis were attributed to reactive radicals.
Les composés volatiles et semi-volatiles organiques de sources anthropogéniques sont des polluants atmosphériques participant à la formation d'ozone troposphérique. Nous avons associé l'adsorption et la photolyse par rayons ultraviolets, pour enlever et détruire ces composés. Nous avons synthétisé des nanoparticules de magnétite, un matériel abondant dans la nature, afin d'éviter la création d'un autre problème de pollution comme il est parvenu avec l'utilisation des fluorocarbure chlorés. L'efficacité d'enlèvement par adsorption atteint un maximum de 98 % pour les composés aromatiques et un maximum de 30% pour les alcanes légers. Les particules ont été regénérées, caractérisées (MET, XRD, BET), et réutilisées; aucune baisse en efficacité d'enlèvement n'est notée. Les expériences de photolyse atteignent une réduction maximale de 30% pour les composés aromatiques et de 20% pour les alcanes légers. Sous nos conditions expérimentales, aucune amélioration n'est notée par l'association des deux processus (adsorption et photolyse). La réduction par adsorption est attribuée aux forces d'attraction London pour les alcanes et aux propriétés acides et basiques pour les aromatiques. La réduction par photolyse s'explique par la formation de radicaux réactifs.

Dans l’atmosphère, les particules d’aérosol jouent un rôle clef sur le climat et, par leur action sur la qualité de l’air, ont un impact néfaste sur la santé publique. Ces particules sont composées d’un mélange complexe d’espèces inorganiques et organiques formées à partir d’une grande variété de sources. Si les sources et mécanismes de production des espèces inorganiques sont désormais relativement bien connus, la caractérisation de la fraction organique des aérosols est beaucoup plus complexe : elle est constituée d’aérosols organiques primaires, émis directement dans l’atmosphère, et d’aérosols organiques secondaires (AOS) produits par la conversion gaz-particules de Composés Organiques Volatils (COV). Afin de comprendre les processus de formation des aérosols organiques, des modèles tridimensionnels de chimie-transport sont mis en œuvre. Or, à ce jour, les concentrations en aérosols organiques observées dans l’atmosphère demeurent sous-estimées par ces modèles. L’objectif de cette thèse est d’étudier les différents processus de transport, d’émissions et de transformations chimiques intervenant dans la formation des aérosols organiques à partir du modèle de chimie-transport WRF-Chem (Weather Research and Forecasting – Chemistry). Les sorties du modèle ont été comparées à des mesures effectuées à la station du puy de Dôme au cours de trois situations correspondant à trois saisons (automne, hiver, été) durant lesquelles des masses d’air de diverses origines ont été échantillonnées. Ces mesures documentent les conditions météorologiques, les propriétés des espèces chimiques gazeuses et des particules d’aérosol. En particulier, les mesures fournies par un spectromètre de masse (AMS : Aerosol Mass Spectrometer), fournissent de informations détaillées sur la variabilité temporelle de la composition chimique des aérosols et notamment sur leur concentration en masse. Les comparaisons modèle/mesures ont montré que les variations saisonnières de la composition chimique des aérosols observées au puy de Dôme étaient bien capturées par le modèle. Cependant, il s’est avéré que les concentrations en aérosols organiques étaient fortement sous-estimées par le modèle et plus particulièrement lors de la situation d’été. La confrontation des origines des masses d’air simulées par le modèle WRF-Chem à celles déterminées par le modèle lagrangien HYSPLIT reconnu pour l’étude de la dispersion atmosphérique et l’analyse des variations de la localisation du sommet du puy de Dôme vis-à-vis de la couche limite atmosphérique ont mis en évidence que le transport était correctement reproduit par le modèle. Les mesures de gaz disponibles au puy de Dôme ont mis en évidence une forte sous-estimation des concentrations en COV d’origine anthropique simulées par le modèle. Des tests de sensibilité ont été réalisés sur les émissions de ces espèces pour restituer les niveaux de concentration observés. Les émissions et les rendements en AOS des COV d’origine anthropique implémentés dans la paramétrisation VBS dédiée aux aérosols organiques dans le modèle ont pu être modifiés afin de reproduire les niveaux de concentration en aérosols organiques observés au puy de Dôme
In the atmosphere, aerosol particles play a key role on both climate change and human health due to their effect on air quality. These particles are made of a complex mixture of organic and inorganic species emitted from several sources. Although the sources and the production mechanisms for inorganic species are now quite well understood, the characterization of the organic fraction is much more difficult to study. Indeed, particulate organic matter comes from primary organic aerosols directly emitted to the atmosphere and secondary organic aerosols (SOA), which are formed from gas-to-particle conversion of Volatile Organic Compounds (VOC). Three-dimensional chemistry-transport models are developed to better understand the organic aerosol formation processes. However, these models underestimate the organic aerosol concentrations. The aim of this thesis is to study the transport, the emissions and the chemical transformations involved in the formation of the organic aerosols using the WRF-Chem chemistry-transport model (Weather Research and Forecasting – Chemistry; Grell .et al., 2005). Model outputs are compared to measurements performed at the puy de Dôme station (France) during three campaigns. These measurements allow for characterizing various air masses and different seasonal behaviours (in autumn, winter and summer). The station hosts many probes for controlling meteorological parameters, gas phase species and aerosol properties. In particular, a mass spectrometer (AMS: Aerosol Mass Spectrometer) provides detailed time evolution of the chemical composition and mass concentration of the particulate matter. The comparisons between model results and observations have shown that seasonal variations of the aerosol chemical composition are captured by the WRF-Chem model. However, the organic aerosols mass concentrations are strongly underestimated and this underestimation is more important for the polluted summer case. The calculated origins of air masses are comparable to the results of the lagrangian model HYSPLIT currently used for atmospheric dispersion. The top of the puy de Dôme is observed to be either in the boundary layer or above depending on the season and these observations are correctly reproduced by the WRF-Chem model. As the anthropogenic VOC concentrations are underestimated by WFR-Chem model, sensitivity tests on the anthropogenic VOC emissions and SOA yields, used in the VBS secondary organic aerosols parameterisation, are done to better reproduce the organic aerosol concentrations observed at the puy de Dôme station

Experiments evaluating the oxidation of 3 VOCs; tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,2, dichloroethane (DCA); in the presence and absence of catalysts UV light and sunlight, at three nominally applied ozone concentrations; high (8.8 mg/l), medium (5.5 mg/l), and low (3.3 mg/l); have demonstrated that the degree of compound removal is dependent on the type of compound. PCE degradation was mainly photolytic, TCE destruction was more dependent on ozone dose, and DCE was the most refractory of the 3 compounds tested. Ozone dose and catalyst type and concentration were also significant, in terms of compound removal. Additional data have shown that the decomposition of dissolved ozone was accelerated in the presence of sunlight over dissolved ozone in the dark, implying that solar catalyzed ozone decomposition would lead to a larger net free radical production over non-catalyzed reactions.

Exhaled breath is a rich and complex matrix containing many hundreds of compounds. Every breath offers the potential of a non-invasive measurement of the biochemical processes occurring in the human body and it is this notion that has led to the application of breath analysis for the detection of disease. With the majority of research in the field being focused on the detection of biomarkers, little has been presented on how the seemingly homeostatic matrix of breath varies during the course of normal life events. The research in this thesis describes how a subject's emotional state, physical state, and daily activities can alter the composition of exhaled breath.

A variety of methods exist to remove volatile organic compound (VOC) air pollutants from contaminated gas streams. As regulatory and public opinion pressures increase, companies are searching for more effective methods to control these emissions. This document is intended as a guide to help determine if existing systems are adequate and to provide additional information to improve the efficiency of the systems. It explores conventional methods of controlling VOC emissions, as well as innovative technologies including membrane separation, plasma destruction, and ozone catalytic oxidation. The conventional technologies covered include condensation, adsorption, absorption (or scrubbing), thermal incineration, flaring, catalytic incineration, and biofiltration. Each chapter includes a description of the technology, a discussion of the types of systems available, notes on the design of the system, economic estimates, an explanation of potential problems, and a list of considerations for installation and maintenance concerns. The final chapter is dedicated to the preparation and characterization of metal catalysts which were developed to improve the reaction rate of VOCs using ozone as an oxidant.
Ph. D.

In recent years, consumers have become increasingly interested in the quality aspects of food. Food quality, in turn, is strongly related to the sensory characteristics such as the flavor. Several scientific studies have shown that the Volatile Organic Compounds (VOCs) released by the food are related to the flavor and can be considered as assistive markers in the production chain. Today, the analysis of VOCs requires fast, non-invasive, and solvent free devices. It has been shown that the VOCs can be extracted, identified, and measured with a Gas Chromatography-Mass Spectrometry (GC-MS) without any pre-concentration or pre-treatment of the food. The main objective of this PhD thesis was to investigate the presence of volatile compounds in dairy products. More precisely, this study aimed in i) qualifying and quantifying VOCs in dairy products, ii) examining their formation and iii) integrating knowledge on VOCs by tracking their release during the whole production process from the raw materials till the final dairy product. In addition, statistical analysis was applied to link VOCs with the genetic characterization of animals, dairy system and individual cow-factors (e.g. stage of lactation, order of parity and milk yield). The identification and quantification of VOCs were performed using fast and non-invasive analytical approaches (Solid Phase Micro Extraction/Gas Chromatography-Mass Spectrometry SPME/GC-MS and Proton Transfer Reaction-Time of Flight-Mass Spectrometry PTR-ToF-MS) that can monitor the evolution of VOCs. To achieve the overall goal, the research was partitioned in four interrelated subparts as described below. The aim of the first chapter was to study the VOCs presence in the headspace of cheese. To this purpose, 150 cheeses ripened for two months were used. The cheeses were obtained through an individual model cheese-making approach using milk from individual Brown Swiss cows. Animals reared in 30 herds belonging to different dairy systems, from traditional (typical of the mountainous area) to modern ones. The study identified 55 VOCs classified in the chemical families of free fatty acids, esters, alcohols, aldehydes, ketones, lactones, terpenes, and pyrazines. We found that dairy system and individual cow characteristics (lactation stage, order of parity and daily milk yield) influenced the volatile compounds. In order, to test the instrument reproducibility and the model cheese-making procedure; data of GC analysis, order of injection of the sample into instrument, and vat were included in the statistical model. In many cases, these analytical factors did not affect the amount of VOCs released by cheese. In the second chapter, the potential of a new spectrometric technique (PTR-ToF-MS) was investigated to study cheese quality traits on a large scale. The PTR-ToF-MS allows direct injection of the sample headspace without extraction or pre-concentration steps, has a shorter analysis time (only a few seconds per sample) and greater sensitivity that permit to monitor on-line the evolution of volatile compounds. The resulting spectral information can provide a very detailed description of samples, which is useful for characterizing food quality and typicality. In particular, we analyzed the volatile fingerprint of 1,075 model cheeses produced using individual milk of Brown Swiss cows reared in 72 herds of different dairy systems. The output of PTR (spectrum) was characterized by more than 600 spectrometric peaks (variables). After removing interfering ions and background noise a set of 240 peaks was selected. Further, based on the results of the first contribution and literature, 61 peaks were identified. These peaks represent the major part of the cheese flavor. To summarize the amount of information, a multivariate analysis (PCA) was applied associating principal components (PC) with the 240 spectrometric peaks. Following, we tried to characterize the PCs through the correlations between PCs and the spectrometric peaks. The effects of dairy system, herd within dairy system, individual cows characteristics (lactation stage, order of parity and milk yield), and vat used for the cheese-making on the PCs and on the 240 peaks were analyzed. Dairy system was correlated with PC and 57 spectrometric peaks, especially when the herds were using Total Mixer Ration (TMR) as feeding technique, including or not maize silage in the diets. Regarding the individual animal characteristics, the most significant effect was the stage of lactation (139 peaks), followed by milk yield and parity, with 31 and 21 peaks, respectively. Finally, the vat used for the cheese-making was not found to be significant, confirming the good reproducibility of the model cheese-making procedure used to study cheese quality aspects. In the third chapter, the effect of cows’ genetics to the VOCs of ripened cheeses was assessed. Principal components and the 240 spectrometric peaks (as described above in the second contribution) were used fitting an animal model in a Bayesian framework. On average, heritability (h2) of 7% for PCs was found, which is similar to h2 of somatic cell count and much lower than the h2 of milk fat content and daily milk yield. It is interesting to note that only a small proportion of peaks showed very low h2 (<7%). The major part of them showed values similar to those found for PCs, while forty peaks presented heritability similar to that of milk yield and other milk quality traits. The variability attributed to the herd was different for the various PC. Results suggest a potential of improvement for several cheese VOCs through genetic selection in dairy cow breeding programs. The aim of the fourth chapter was to study the effect of summer transhumance on the quality traits of dairy products. Due to the extended work, this contribution was further splitted into two parts. In the first part, the evolution of milk and cheese quality characteristics were studied, while in the second part the evolution of VOC content of dairy products was analyzed. For the first part, chemical characteristics and technological properties of 11 dairy products obtained during summer transhumance of cows to Alpine pastures (Malga) were analyzed. Dairy products obtained throughout this period are known to give origin to high-value, healthier products, and extra tasty,. Bulk milk from 148 dairy cows reared day and night on Alpine pasture (1,860 m a.s.l.) was used. We performed 7 experimental cheese-making according to traditional mountain techniques, one every two weeks, using milk produced during the summer transhumance (from June to September). For each cheese-making we collected: milk from the evening milking (day before the cheese-making), the same milk the following morning (after natural creaming), the cream separated, the whole milk from the morning milking, the milk in vat obtained mixing the creamed evening milk with the whole morning milk, the fresh curd, the whey, the ricotta obtained from whey, and the residual scotta. Moreover, the curd was used to produce typical “Malga” cheese that was ripened for 6 and 12 months. The chemical characteristics were measured with infrared technology. Results highlighted variation in milk yield, milk chemical composition, cheese yield and curd recoveries and/or loss of nutrients in the traditional cheese-making. In particular, a reduction of milk yield, fat, protein and lactose contents of milk during summer transhumance was observed. Nevertheless, the return to lowland farming systems of the cows at the end of grazing season, positively affected milk yield and milk chemical composition. The average of cheese yield was 14.2%, while recoveries of fat, protein, total solids and energy were 85.1%, 77.8%, 49.4% and 58.1%, respectively. These results were in accordance to those found in the literature. For the second part of this chapter, the VOCs content of sample headspace was measured through SPME/GC-MS. Forth nine VOCs belonging to the chemical families of alcohols, aldehydes, free fatty acids, ketones, esters, lactones, terpenes, phenolic, and sulphur compounds were detected. In addition, the evolution of VOCs and their chemical family across the cheese- and ricotta-making processing as well as during the cheese ripening period was tracked. The comparison between VOCs concentration of 4 types of milk (whole evening, creaming milk, whole morning, milk in vat) showed that the creaming process significantly affected about half of all the volatile organic compounds analyzed, followed by the effects of milking (evening milking vs. morning milking) and the mixing (creamed milk mixed with whole morning milk). In general, the cream, in contrast to curd and ricotta, showed higher content of free fatty acids, sulphurs and terpenes compounds. Moreover, in ricotta a higher VOC concentration was observed compared to the curd, probably due to the high temperature required during the ricotta process. The effect of the progressive nutrient depletion of milk was investigated by contrasts between VOC concentration of milk in the vat, whey, and scotta. Although milk contains a greater amount of nutrients, whey and scotta have shown a higher concentration of VOCs with the exceptions of esters, sulphurs, terpenes and phenolic compounds. Finally, the effect of ripening was tested by comparing the quantity of VOCs of curd and of aged cheeses (6 and 12 months). The release of volatile compounds increased with increasing ripening period in relation with the enzymatic and microbiological activity of cheese. In summary, the spectrometric techniques (SPME/GC-MS and PTR-ToF-MS) used in this work demonstrated to be very efficient to characterize the volatile organic compounds of dairy products. The dairy system, and cow related factors affected the volatile fingerprint of ripened cheeses. Particularly, concerning the individual animal source of variation, lactation stage was the most important effect followed by the cow’s parity and the milk yield. On the basis of phenotypes used in this work, the traits collected offered the potential for a genetic analysis to be carried out. The genetic analysis demonstrated the existence of an exploitable genetic variability of the volatile profile of cheese that might be useful for an (in)direct selection of dairy cows for cheese quality traits in breeding programs. Nevertheless, further research is needed in this area. In the era of genomics for e.g., it might be interesting to associate genomic regions to specific VOCs. This information might be useful for genomic breeding programs. The evolution of volatile compounds across the production chain depends on specific technological aspects, such as the process of natural creaming, the temperature of coagulation, and the ripening period. The monitoring of volatile fingerprint permits to obtain dairy products with specific organoleptic characteristics useful to differentiate them on the market and to improve the supply chain efficiency on the basis of quality aspects.
Negli ultimi anni, il consumatore è diventato sempre più sensibile agli aspetti qualitativi degli alimenti, i quali sono fortemente influenzati dalle caratteristiche sensoriali come l’aroma. Diversi lavori scientifici hanno dimostrato che i composti volatili (VOCs) rilasciati dall’alimento sono correlati con il suo aroma e possono essere considerati come traccianti delle filiere alimentari. Oggi, l’analisi dei VOCs richiede strumenti rapidi, sensibili, non invasivi e che abbiano bisogno dell’impiego di pochi solventi durante la preparazione del campione. E’ stato dimostrato che i VOCs possono essere estratti, misurati e identificati con la Gas Cromatografia di Massa (GC-MS) senza pre-concentrazioni o pre-trattamenti dell’alimento da analizzare. Gli obiettivi principali della tesi di dottorato erano di studiare la presenza di composti volatili nei prodotti lattiero-caseari. Più precisamente, questo studio aveva come obiettivi di i) qualificare e quantificare i VOCs nei prodotti lattiero-caseari, ii) esaminare la loro formazione e iii) integrare le conoscenze acquisite su questi composti attraverso tutta la filiera di produzione dalla materia prima fino al prodotto finito. Inoltre, analisi statistiche sono state utilizzate per collegare i VOCs con la caratterizzazione genetica degli animali, il sistema di allevamento e le caratteristiche individuali delle vacche (es. stadio di lattazione, ordine di parto e produzione giornaliera di latte). L’identificazione e la quantificazione dei VOCs sono state fatte utilizzando tecniche analitiche precise, veloci e non invasive (Solid Phase Micro Extraction/Gas Chromatography-Mass Spectrometry SPME/GC-MS and Proton Transfer Reaction-Time of Flight-Mass Spectrometry PTR-ToF-MS). Per rispondere agli obiettivi generali della tesi, l’attività di ricerca è stata divisa in cinque parti connesse tra di loro. L’obiettivo nel primo capitolo era di studiare i composti volatili presenti nello spazio di testa di campioni di formaggio. Per questo scopo, sono stati analizzati 150 formaggi stagionati per due mesi. I formaggi sono stati prodotti utilizzando una metodica di caseificazione individuale usando latte individuale di vacche di razza Bruna. Gli animali sono stati allevati in 30 aziende appartenenti a diversi sistemi di allevamento, da tradizionale (tipico della realtà montana) a moderno. In questo studio sono stati identificati 55 VOCs per ogni formaggio, classificati in diverse famiglie chimiche: acidi grassi, esteri, alcoli, aldeidi, chetoni, lattoni, terpeni e pirazine. Dai risultati emerge che il sistema di allevamento e le caratteristiche individuali delle vacche (stadio di lattazione, ordine di parto e produzione giornaliera di latte) influenzano i composti volatili. Inoltre, per testare la riproducibilità dello strumento e della metodica di caseificazione; la data di analisi cromatografica, l’ordine d’iniezione del campione nello strumento (GC), e la caldaia di caseificazione erano inclusi nel modello statistico. In molti casi, questi fattori analitici/strumentali non influenzano la quantità di VOCs rilasciata dai formaggi. Nel secondo capitolo, il potenziale di una nuova tecnica analitica (PTR-ToF-MS) è stato approfondito per studiare, su larga scala, le caratteristiche qualitative del formaggio. Il PTR-ToF-MS dal punto di vista analitico, permette un’iniezione diretta del campione senza estrazione o pre-concentrazione, ha un breve tempo di analisi (solo pochi secondi per campione) e grande sensibilità consentendo di monitorare in tempo reale l’evoluzione dei composti volatili. L’analisi produce uno spettro molto dettagliato che può essere utile per la caratterizzazione delle qualità e della tipicità dell’alimento. In particolare, è stata analizzata l’impronta aromatica di 1,075 formaggi prodotti utilizzando latte individuale di vacche di razza Bruna allevate in 72 aziende appartenenti a diversi sistemi di allevamento. L’impronta aromatica (spettro) era caratterizzata da più di 600 picchi (variabili) per ogni formaggio. Gli spettri sono stati analizzati e dopo la rimozione degli ioni interferenti e del rumore di fondo è stato selezionato un data set costituito da 240 picchi per ogni formaggio. In seguito, basandosi sui risultati del primo contributo e sulla letteratura sono stati identificati i picchi più importanti (61) in termini quantitativi e qualitativi. Per sintetizzare la quantità di informazioni ovvero estrarre delle componenti principali (PC) è stata fatta un’analisi multivariata (PCA) a partire dai 240 picchi spettrometrici. In seguito, le PCs sono state caratterizzate sulla base delle loro correlazioni con i 240 picchi spettrometrici. Sono stati analizzati gli effetti del sistema di allevamento, dell’azienda entro sistema di allevamento, le caratteristiche individuali delle vacche (stadio di lattazione, ordine di parto e produzione di latte), e caldaia di caseificazione sulle PCs e sui 240 picchi. Dai risultati emerge che il sistema di allevamento è correlato con le PC e 57 picchi, specialmente quando le aziende come tecnica di alimentazione utilizzano il carro miscelatore (TMR) con e senza insilati nella dieta. Considerando le caratteristiche individuali delle vacche, l’effetto più significativo è lo stadio di lattazione (139 picchi), seguito dalla produzione di latte e dall’ordine di parto, con 31 e 21 picchi, rispettivamente. Infine, la caldaia di caseificazione è un effetto spesso non significativo, confermando la buona riproducibilità della micro-caseificazione utilizzata anche per lo studio di aspetti qualitativi del formaggio. Nel terzo capitolo è stato studiato l’effetto della genetica dell’animale sui composti volatili dei formaggi. A tale scopo, sono state analizzate le componenti principali (estratte come discusso sopra nel secondo contributo) e i 240 picchi spettrometrici (PTR-ToF-MS) utilizzando un modello animale con un approccio Baesiano. Dai risultati emerge in media un’ereditabilità (h2) del 7 % per le componenti principali, la quale è simile all’h2 trovata per le cellule somatiche e leggermente più bassa di quella del contenuto di grasso nel latte e della produzione giornaliera di latte stimate in precedenza sugli stessi animali. E’ interessante osservare che solo una piccola quantità di picchi ha una bassa h2 (<7%). La maggior parte di essi presenta valori simili a quelli trovati per le PCs, mentre 40 picchi presentano ereditabilità simile a quella trovata per la produzione giornaliera di latte e ad altre caratteristiche qualitative del latte. La variabilità attribuita all'azienda è risultata diversa per le PCs. Questi risultati dimostrano che esiste un’interessante variabilità genetica di alcuni VOCs che potrebbe essere potenzialmente utilizzata nei programmi di miglioramento genetico. L’obiettivo nel quarto capitolo era di studiare l’effetto della transumanza sulle caratteristiche qualitative di prodotti lattiero-caseari. Vista la grande mole di dati, questo contributo è stato diviso in due parti tra loro connesse. Nella prima parte è stata studiata l’evoluzione della qualità del latte e del formaggio, mentre nella seconda parte è stata analizzata l’evoluzione dei composti volatili dei prodotti lattiero-caseari nel processo di caseificazione. Nella prima parte, sono state analizzate le proprietà fisiche, chimiche e tecnologiche di 11 prodotti lattiero-caseari raccolti durante la transumanza al pascolo Alpino (Malga) di vacche da latte. E’ risaputo che i prodotti ottenuti durante il periodo di alpeggio possono avere un valore aggiunto dovuto alle elevate proprietà nutrizionali, salutistiche e aromatiche. Per approfondire le conoscenze finora acquisite, è stata fatta questa prova in cui è stato utilizzato il latte di massa prodotto da 148 vacche allevate giorno e notte al pascolo (1,860 m s.l.m.). Durante l’esperimento, sono state fatte 7 caseificazioni seguendo tecniche tradizionali, una ogni 2 settimane, utilizzando il latte prodotto durante la transumanza (da giugno a settembre). Sono stati raccolti per ogni caseificazione: il latte della mungitura della sera (giorno prima della caseificazione), lo stesso latte il mattino successivo (dopo il processo di scrematura naturale), la panna di affioramento, il latte della mungitura del mattino, il latte in caldaia ottenuta dalla miscela tra il latte scremato della mungitura della sera con il latte della mungitura del mattino, la cagliata, il siero, la ricotta ottenuta dal siero e il residuo della lavorazione ossia la scotta. Inoltre, la cagliata è stata usata per produrre formaggi di “Malga” che sono stati stagionati per 6 e 12 mesi. Le caratteristiche chimico-fisiche sono state misurate con una tecnologia a infrarosso. I risultati dimostrano una variazione della produzione giornaliera e composizione chimica del latte, resa in formaggio e recupero/o perdita di nutrienti nel processo di caseificazione tradizionale. In particolare, si è osservata una riduzione della produzione giornaliera di latte, grasso, proteine e lattosio del latte durante la transumanza estiva. Tuttavia, si è anche osservato un effetto positivo sulla produzione e la composizione chimica del latte del ritorno delle vacche nelle aziende di fondo valle alla fine della stagione dell’alpeggio. La resa media di formaggio in questo lavoro è risultata del 14.2%, mentre i recuperi di grasso, proteine, solidi totali ed energia sono del 85.1%, 77.8%, 49.4% e 58.1%, rispettivamente. Questi risultati sono in linea con quelli trovato in letteratura. Nella seconda parte di questo contributo, è stato misurato il contenuto di composti volatili nello spazio di testa dei campioni con la tecnica SPME/GC-MS. Dopo l’analisi, sono stati identificati 49 VOCs appartenenti alle famiglie chimiche degli alcoli, aldeidi, acidi grassi, chetoni, esteri, lattoni, terpeni e composti solforati e fenolici. Inoltre, è stata studiata l’evoluzione dei VOCs e delle loro famiglie chimiche attraverso i processi di caseificazione, di produzione della ricotta e di stagionatura del formaggio. Il confronto tra la concentrazione dei VOCs dei 4 tipi di latte (intero e scremato della sera, intero del mattino, caldaia) ha dimostrato che il processo di scrematura influenza la concentrazione di metà dei composti volatili analizzati, seguito dall’effetto della mungitura (intero della sera vs. intero del mattino) e dall’effetto del mescolamento (latte scremato della sera mescolato in parti uguali con il latte del mattino). In generale, la panna, rispetto a cagliata e ricotta, ha un maggiore contenuto di acidi grassi, terpeni e composti solforati. Inoltre, la ricotta rispetto alla cagliata ha un’elevata concentrazione di VOC, probabilmente dovuta alla maggiore temperatura utilizzata durante il processo di produzione. L’effetto del progressivo depauperamento di nutriente del latte è stato studiato attraverso il confronto tra latte in caldaia, siero e scotta. Sebbene il latte abbia un maggiore contenuto di nutrienti, il siero e la scotta hanno una maggiore concentrazione di VOC ad eccezione delle famiglie chimiche degli esteri, terpeni, composti solforati e fenolici. Infine, l’effetto della maturazione è stato valutato attraverso il confronto tra le quantità di VOC della cagliata e dei formaggi stagionati (6 e 12 mesi). Il rilascio dei composti volatili incrementa con l’aumento del periodo di maturazione probabilmente dovuto a una maggiore attività enzimatica e microbiologica nel formaggio. In conclusione, le tecniche analitiche di spettrometria di massa utilizzate in questo lavoro (SPME/GC-MS e PTR-ToF-MS) hanno permesso di caratterizzare i composti volatili dei prodotti lattiero-caseari in maniera efficiente. Il sistema di allevamento, le caratteristiche individuali delle vacche hanno influenzato l’impronta aromatica di formaggi individuali stagionati. In particolare, riguardo alle caratteristiche individuali degli animali il principale effetto era lo stadio di lattazione seguito da ordine di parto e produzione giornaliera di latte. Sulla base dei fenotipi raccolti in questo lavoro è stato possibile effettuare un’analisi genetica, la quale ha dimostrato l’esistenza di un’interessante variabilità genetica connessa ai composti volatili del formaggio che potrebbe essere utile per una selezione (in)diretta delle vacche da latte sulla base di aspetti qualitativi in programmi di miglioramento genetico. Tuttavia sono necessarie altre ricerche in quest’area per esempio, nell’era della genomica, sarebbe interessante associare qualche regione specifica del genoma ai composti volatili. L’evoluzione dei composti volatile attraverso la filiera di produzione dipende da specifici aspetti tecnologici, come l’affioramento della panna, la temperatura di coagulazione e il periodo di stagionatura. Il monitoraggio dell’impronta aromatica permette di ottenere prodotti lattiero-caseari con delle specifiche caratteristiche organolettiche utili a differenziare il prodotto sul mercato e a migliorare l’efficienza dell’intera filiera produttiva sulla base di aspetti qualitativi.

Volatile and semi-volatile organic compounds are ubiquitous, and some of them are hazardous. The ability to rapidly detect and identify trace levels of them in air has become increasingly important. The conventional device used today for sampling and concentrating them in air is thermal desorption tubes filled with specific sorbents, which can only collect air samples at flow rates of 100-200 mL/min. In order to detect low concentration (ppt level) VOC compounds, long sampling time (>2 h) and sensitive detection are required. At the same time, portable instrumentation for on-site analysis has been developing rapidly. The somewhat lower performance of portable instruments compared to benchtop systems requires the sampling of even greater sample volume in order to reach the same detection limits. In this study, two high flow rate air sampling devices, i.e., a multi-capillary trap and a concentric packed trap, were developed to sample a large volume of air in a short time period. The multi-capillary trap was constructed by bundling analytical capillary gas chromatography columns together in parallel. As low as single digit ppt detection limits were reached in less than 25 min with this trap, and as high as 8.0 L/min flow rate was sampled. The simple and compact multi-capillary trap could be easily used with a conventional thermal desorption system to perform high flow rate sampling. A concentric packed high flow rate trap was also developed by packing sorbent layers concentrically around an empty tube. The concentric packed trap achieved a high flow rate (>10 L/min) because it had a high surface area and short sorbent bed. Also, its large sorbent amount (>1 g) provided large breakthrough volume (>100 L) required to achieve low detection limits. An equilibrium distribution sampling system was developed by absorbing selected analytes in granular PDMS to provide calibration for on-site instrumentation. Furthermore, a needle trap device was coupled in tandem to both high flow rate air samplers to perform second-stage concentration of VOCs down to the ppt level. Concentration factors of 104 to 105 were achieved within 30 min using both systems, i.e., over 10 to 100 times more sample was collected compared to conventional TD systems.

Ce manuscrit s’intéresse à une filière globale et durable de dépollution des eaux souterraines. Le polluant cible, le tétrachloroéthylène, est un composé organique volatil. La première étape de cette filière est la séparation du contaminant de l’eau. Elle a été réalisée par adsorption sur charbons actifs dans une colonne en lit fixe. Les résultats obtenus en laboratoire sur les capacités et les cinétiques d’adsorption ont permis de montrer l’efficacité de ce procédé. Un modèle issu de ces expériences a représenté correctement des conditions opératoires variées correspondant à celles utilisées dans l’industrie. Ce modèle a été validé par un pilote préindustriel installé sur site et fonctionnant en conditions réelles. La gestion des charbons actifs chargés en polluant a été étudiée. La régénération thermique a été privilégiée. Cette opération présente l’intérêt de rétablir les capacités d’adsorption des carbones activés et de récupérer les polluants en phase liquide. Bien que préférable à la production d’adsorbants, elle pourrait encore être plus durable et compétitive économiquement en effectuant le traitement thermique par voie solaire. Il a été montré que le taux de régénération est le même pour les régénérations solaire et classique. Il est donc possible, dans le cas du tétrachloroéthylène, de remplacer une source d’énergie fossile par le soleil. La solution de distillat obtenue lors de la régénération peut être minéralisée par photocatalyse hétérogène. Cette opération a été réalisée en laboratoire avec une lampe reproduisant le spectre solaire. La faisabilité de la photocatalyse solaire sur le résidu issu de cette filière de dépollution a ainsi été montrée
This manuscript focuses on a comprehensive and durable treatment of polluted groundwater. The target contaminant, tetrachlorethylene, is a volatile organic compound. The first step in the treatment is the separation of contaminants. It was carried out by adsorption on activated carbons in a fixed bed column. The results obtained in the laboratory on the adsorption capacity and kinetics have shown the efficiency of this process. A mathematic model represented properly the various operating conditions corresponding to those used in the industry. This model has been validated by a pre-industrial pilot installed onsite and operating in real conditions. Management of spent activated carbons was studied. The thermal regeneration was chosen because it has the interest to restore the adsorption capacity of adsorbents and to collect the pollutants in a liquid phase. Although preferable to the production of activated carbons, it could still be economically more competitive and more sustainable by performing the heat treatment by solar means. It has been shown that the regeneration rate is the same for the solar and classical regenerations. It is therefore possible, in the case of tetrachlorethylene, to replace a fossil energy source by the sun.The distillate solution obtained during the regeneration can be mineralized by heterogeneous photocatalysis. This operation was carried out in the laboratory with a lamp reproducing the solar spectrum. The feasibility of solar photocatalysis on the final residue of the water treatment has been shown

La composition de l'air intérieur est complexe et fortement influencée par les activités humaines. Celles-ci engendrent notamment l'émission de composés organiques et de particules. Les inquiétudes grandissantes quant à la qualité de l'air intérieur et à son impact sanitaire ont contraint les pouvoirs publics à prendre des mesures pour mieux assurer son suivi. Parmi les activités humaines fréquemment soupçonnées de contribuer à la contamination de l'air intérieur, on retrouve l'utilisation de parfums d'ambiance de types encens et bougies. De récentes études ont montré que cette pratique pouvait entraîner l'émission de composés organiques volatils (COV) et de particules. Une des carences liées à ces études résulte dans le fait qu'il n'existe pas de protocole de prélèvement et de mesures normalisés pour ce type de pratique, rendant l'exploitation et l'inter comparaison des résultats sujette à beaucoup de controverses. Les industriels français ont dès lors souhaité réagir, par la mise en place d'une méthodologie commune de mesure des émissions induites par la combustion des parfums d'ambiance. Le but de ce travail est de développer et de valider un dispositif expérimental permettant de mieux contrôler la combustion et les paramètres environnementaux qui l'influencent, afin de disposer d'un protocole expérimental calibré et reproductible. Ainsi, après avoir étudié les types de polluants et les possibilités de prélèvements et d'analyses associées, l'étude a été conduite en trois étapes. La première a été réalisée dans une pièce laboratoire simulant en taille réelle la pièce d'un logement. Elle a permis de déterminer le type de composés émis (COV et particules) par la combustion de parfums d'ambiance et les niveaux de concentrations associés. La seconde étape consistait en la réalisation d'un plan d'expériences complet dans une enceinte d'essais d'émissions pour déterminer l'influence de la température, de l'humidité relative et du taux de renouvellement d'air sur les niveaux émissions. Enfin, dans le cadre de la dernière étape, la méthode et les connaissances acquises précédemment ont été transférées à une enceinte d'essai climatique de faible volume, afin de permettre la réalisation d'analyse en routine
The indoor air composition is complex and widely influenced by human activities. These practices generate organic compound and particles. Growing concerns about indoor air quality and its impact on health have forced the government to make more studies. Among the human practices, recent studies shown that incense and candle combustion could result in the emission of volatile organic compounds (VOC) and particles. However, there is no standard sample protocol for measuring these emissions. The results comparison is then largely controversy. French manufacturers want to develop a methodology for emissions controlling due to the combustion of incense and candle processes. Through this experimental system, they want to learn much more about these processes and emissions control to anticipate the new law. Thus, after studying about the types of pollutants and sampling/analysis protocol associated, three types of studies were conducted. The first study was carried in a room of a house, to determine which kind of compounds were emitted (VOCs and particulate matter) and their concentration levels. The second study was to apply a full factorial design in a chamber emission test, to determine temperature, relative humidity and air exchange rates emissions influences. Finally, in a last study, the method and the knowledge acquired previously were transferred to a climate test chamber of small volume, allowing manufacturers to make routine analysis