Recently, the production of lithium-ion batteries (LIB) has grown rapidly, highlighting the need for efficient and environmentally friendly recycling of LIB waste. In this work, the usage of so-called deep eutectic solvents (DESs) for the leaching of the LIB cathode material lithium cobaltoxide is investigated. The initial DESs investigated are mixtures of poly(ethylene glycol) (PEG200) and an organic acid: tartaric, ascorbic, citric, oxalic or succinic acid (PEG:TA (4:1), PEG:AA (8:1), PEG:CA (4:1), PEG:OA (2:1) and PEG:SA (6:1), the molar ratio in parenthesis). Thermogravimetric analysis shows that the solvents are stable up to 180-190 °C. DESs were analyzed with FTIR spectroscopy, pH was measured using a pH-meter and viscosity using a rolling-ball viscometer. The highest leaching efficiency was obtained using PEG:AA followed by PEG:OA, both having the ability to reduce Co(III). This ability was dominant over pH and viscosity influence. For the other three solvents, leaching efficiency increases in the order of decreasing pH (PEG:TA>PEG:CA>PEG:SA). More investigations of leaching as a function of time are needed to determine the impact of viscosity. PEG:CA and PEG:AA are used to study the impact of solid-to-liquid ratio. For PEG:AA the optimal S/L-ratio is 20 mg/g. For PEG:CA the optimal S/L-ratio is different for Li and Co. Three additional CA based DESs are made using ethylene glycol (EG) and choline chloride (ChCl): EG:CA, ChCl:EG:CA and ChCl:PEG:CA. Adding ChCl to EG:CA and PEG:CA increases the leaching efficiency from ca 5 and 10 to ca 30% and the color changes from pink to blue, indicating the formation of tetrachlorocobalt complexes. This reaction may produce chlorine gas, although none was detected using potassium iodide starch paper. Study of leaching as afunction of time of ChCl:EG:CA shows the reaction slows down significantly after 24 h, indicating that the reaction has reached or is near equilibrium at this point. Antisolvent crystallization of this solvent using ethanol was not succesful.

Chlorinated ethenes are considered one of the most prevalent sources of groundwater contamination in developed countries. Natural attenuation of chlorinated ethenes is possible through the process of microbial reductive dechlorination. Reductive dechlorination can occur in contaminated aquifers where there are sufficient amounts of organic carbon and reducing redox conditions to support dechlorinating microorganisms. Natural organic carbon (NOC) from dissolved aquifer sediment is thought to be the source of fermentable compounds needed to produce molecular hydrogen that functions as the primary electron donor for reductive dechlorination. Therefore, in an anaerobic aquifer, the production of molecular hydrogen from the fermentation of NOC drives the reductive dechlorination process. The variability and distribution of potential bioavailable organic carbon (PBOC) at a site is relatively unknown and any potential relationships between PBOC and the physical properties of the aquifer sediment have not been evaluated. Exploring relationships between the grain size of aquifer sediment PBOC may help to determine the feasibility of natural attenuation as a long-term remediation strategy at chlorinated ethene-contaminated sites. Because hydraulic conductivity is directly related to aquifer sediment grain size, zones of high hydraulic conductivity may promote greater microbial activity or biodegradation because of the increased availability of PBOC and nutrient flux. To determine potential relationships between PBOC and aquifer sediment grain size, two experiments were performed. PBOC was measured for 106 sediment samples impacted by chlorinated solvent contamination from an anaerobic type II site through a multiple liquid extraction process (Rectanus et al. 2007). Grain size distributions for each of the 106 sediment samples were determined by conducting sieve analyses. The results of both experiments were compared to explore relationships between PBOC and sediment grain size and to evaluate spatial distribution of both in the surficial aquifer. / Master of Science

No / Mechanochemical synthesis has been applied to the rapid synthesis of Deep Eutectic Solvents (DESs), including Reline 200 (choline chloride : urea, 1 : 2), in a continuous flow methodology by Twin Screw Extrusion (TSE). This gave products in higher purity and with Space Time Yields (STYs), four orders of magnitude greater than for batch methods

The feasibility of applying a recently developed liquid-liquid extraction method termed Predispersed Solvent Extraction (PDSE) in an <i>ex situ</i> pump-and-treat system to remove trace amounts of dissolved chlorinated solvents like perchloroethylene (PCE) and trichloroethylene (TCE) from contaminated ground water has been investigated. In PDSE, the solvent is comminuted into globules with diameters ranging from submicron to 100 microns, and stabilized by a surfactant film prior to contact with the aqueous feed. These stabilized globules, termed oil-core aphrons (OCAs), disperse readily in water since water is the continuous phase in systems where the oil-water phase ratios can be as high as 9. Due to their fine particle size and large surface area, high extraction mass-transfer rates are achieved with minimal mixing. OCA phase separation from water can be expedited with microbubble foam flotation. Experiments in this investigation focused on PDSE process development for this groundwater remediation application. Distribution coefficients for PCE and TCE in possible OCA solvents were determined experimentally and agree with published calculated values. Various surfactant/solvent OCA formulations using the aforementioned solvents were examined with emphasis on creating a weakly stable dispersion which would maximize extraction efficiency yet destabilize sufficiently to permit rapid flotation with minimum losses in the raffinate. Accelerating phase separation, hence solvent recovery, through dispersion chemical destabilization with salts, coagulants, and flocculants at varied pH was examined with and without microbubble flotation. The presence of OCAs in the aqueous phase reduced vapor phase concentrations of PCE as much as 96% and was assessed through apparent Henry's Law constants. TCE concentrated in dodecane OCA extract was degraded with a CO-dehydrogenase enzyme complex to cis 1,2-dichloroethylene, trans 1,2-dichloroethylene, and 1,1-dichloroethylene, and vinyl chloride as a possible means of destroying TCE dissolved in the extract. Based on the implications of these experiments, the development of a PDSE <i>ex situ</i> pump-and-treat system appears technically feasible and a conceptual process layout has been provided. / Master of Science

Les objectifs environnementaux (COP21) visant à réduire les émissions de gaz à effet de serre et l'impact de l'industrie sur la nature, font face au défi de la demande croissante d'énergie et de produits. Les procédés chimiques sont les premiers en cause lorsqu’ils mettent en œuvre des solvants. L'ingénierie des solvants est une solution innovante qui vise à trouver des milieux alternatifs bénins possédant les propriétés de solvant adaptés pour chaque étape du procédé.Dans cette perspective, nous avons étudié les Liquides expansés par un gaz (LEGs), qui sont desliquides dont le volume augmente sous l’effet d’un gaz dissous sous pression. En particulier, le CO2 peut être utilisé comme agent d'expansion pour obtenir des liquides expansés par du CO2(LECs), combinant les avantages du CO2 et du solvant. La phase expansée peut contenir des concentrations élevées de CO2, jusqu'à 80%, selon le solvant, ce qui conduit à une réduction du besoin du solvant organique, mais aussi à des changements des propriétés physicochimiques et de transport de la nouvelle phase expansée. On peut de plus moduler ces propriétés par la pression et la température, d'une manière réversible, et améliorer la séparation des produits. Dans cette étude, différents solvants biosourcés ont été utilisés pour obtenir des systèmes expansés par du CO2, tels que les acétates d'alkyle, les carbonates organiques, les méthoxybenzènes, etc.La connaissance des équilibres de phase, des propriétés de solvatation et de transport est essentielle pour concevoir des processus qui exploitent le comportement particulier de ces systèmes biphasiques. Deux approches principales ont été utilisées pour caractériser ces systèmes. Dans un premier temps, des mesures ont été effectuées dans une cellule à haute pression et à volume variable pour évaluer la polarité au travers du paramètre Kamlet-Taft (KT) *(dipolarité / polarisabilité) dans les solvants expansés par du CO2 sous des pressions allant jusqu'à 30 MPa. La technique utilisée a été la spectroscopie UV-Vis suivant le déplacement hypsochromique du Rouge de Nile, une sonde solvatochromique déjà utilisée pour obtenir les paramètres KT dans des solvants purs. De plus, des mesures d'équilibre vapeur-liquide (ELV) ont été effectuées pour obtenir la composition de la phase expansée à différentes pressions et températures afin de comprendre la solvatation du CO2 dans les solvants organiques et de fournir des informations manquantes dans la littérature. En deuxième lieu, dans une approche plus théorique, les données ELV ont été utilisées pour calculer numériquement d'autres propriétés telles que la densité et la viscosité. Des équations d'état et des simulations par dynamique moléculaire (DM) ont été utilisées ; ces dernières donnant de meilleurs résultats dans un mode prédictif de la masse volumique et permettant de suivre les positions moléculaires au cours du temps, qui peut être liée à de nombreuses propriétés, y compris la viscosité étudiée ici. Ces calculs ont été effectués en utilisant un champ de force de type Amber adapté. Les résultats obtenus dans l’ensemble complètent les données de la littérature existante et apportent de nouvelles informations sur les propriétés des LEGs. Par exemple, le comportement non linéaire de l'expansion volumétrique, vérifié après les déterminations de masse volumique sur les simulations DM à l'équilibre, est une clé dans la compréhension des interactions soluté-solvant ; ainsi que les valeurs KT * obtenues qui confirment la large gamme de polarité couverte par ces systèmes.Enfin, certains systèmes expansés par du CO2 ont été utilisés pour produire des nanoparticules de TiO2 pour panneaux solaires, améliorant leur surface spécifique et donc leur efficacité en tant que semi-conducteurs ; et d’autres ont été appliqués à un processus d'activation enzymatique entraînant une augmentation significative du taux de conversion / Over the last two decades, environmental goals (COP21) aiming to reduce Greenhouse Gasemissions and industry impact on nature, face the challenge of the increasing demand for energyand products. Chemical processes are in the center of the scene because of the use of solvents.Solvent engineering is the strategy to find alternative benign media for different applications, oreven to adapt solvent properties to respond each stage of a process, and represents aninteresting alternative to propose innovative solutions to industrial problems. With this perspective,Gas-expanded Liquids (GXLs), which are liquids whose volume is expanded by a pressurizeddissolved gas, represent a very promising tool yet to be implemented in the industry. CO2 can beused as the expansion agent to obtain CO2-expanded Liquids (CXLs), combining both the CO2and the solvent’s advantages. The expanded phase can contain high concentrations of CO2 (up to80%, depending on the solvent), which can lead not only to an effective reduction of the need foran organic solvent, but also to changes in the physicochemical and transport properties of the newexpanded phase, that can now be tuned by pressure and temperature in a reversible fashion, andimprove product separation. In this study, different bio-sourced solvents have been used to obtainCO2-expanded systems, such as alkyl acetates, organic carbonates, methoxybenzenes, etc.Knowledge of phase equilibria, solvation and transport properties are fundamental to designprocesses that exploit the peculiar behavior of these two-phase systems. Two main approacheshave been used to characterize these systems. At first, physical determinations were carried outin a high pressure, variable volume view cell, to measure polarity through Kamlet-Taft (KT) *parameter (dipolarity/polarizability) in the selected CO2-expanded solvents under pressures up to30 MPa. The technique used was UV-Vis spectroscopy following the hypsochromic shift of NileRed, a solvatochromic probe that has already been used to obtain KT parameters in neat solvents.Also, Vapour-Liquid Equilibria (VLE) measurements were performed to obtain the expanded phasecomposition at different pressures and temperatures as an attempt to understand CO2 solvation inorganic solvents and to provide missing information in literature. In second place, in a moretheoretical approach, VLE data was used to numerically calculate other properties such as densityand viscosity. Both Equations of State (EoS) and Molecular Dynamics (MD) simulations wereused, giving this last technique better results in a pure predictive mode like in the case of densitydeterminations; in addition to the ability to trace molecular positions over time, which can berelated to many properties, including the here studied viscosity. These calculations were carriedout using an Extended AMBER potential, which led to fairly good results compared to specific-usepotentials available in literature, with the advantage of the general-use possibility. From all thesedeterminations, different conclusions were drawn both agreeing with existing and providing newdata to the literature surrounding this promising subject. For instance, the generally non-linearbehavior of volumetric expansion, verified after density determinations on equilibrium MDsimulations, that is key to evaluate solute-solvent interactions; as well as the KT * values obtainedthat confirm the large range of polarity covered by these systems. Finally, some CO2-expandedsystems were used to produce TiO2 nanoparticles for solar panels improving their specific surfaceand therefore their efficiency as semiconductors; and some others applied to an enzyme activationprocess leading to significant enhancement in conversion rate

This thesis entitled “Organic Transformations in Water: Synthetic and Mechanistic Studies towards Green Methodologies” is in two parts. Part-I describes various synthetic studies aimed at developing improved methodologies; Part-II describes certain mechanistic studies directed towards an improved understanding of phase transfer catalysis and the hydrophobic effect. Water is uniquely advantageous as a solvent. It is environmentally benign, non-flammable, liquid over a wide temperature range and possesses a high heat capacity that makes it inherently safe. Water also catalyses chemical transformations between insoluble organic reactants. Water thus serves as a reaction medium, a product partitioner and a reaction catalyst.1 Part-I:- Reactions in Water under both Microwave and Ambient Conditions Part-I is further divided into three chapters. Chapter II deals with reactions of 2-nitroalcohols (2NAs), and is divided into three sections. Section A describes the synthesis of nitroalkanes via the microwave-assisted, water-mediated chemoselective reduction of 2NAs using tributyltin hydride (Bu Scheme 1 ). The 2NAs, synthesized from nitromethane and aldehydes (aliphatic, alicyclic, heterocyclic or m- & p-substituted aromatic aldehydes), were converted into corresponding nitroalkanes in excellent yields. The 2NAs derived either from substituted nitromethane [nitroethane, (nitromethyl)benzene, etc.] or bulky aldehydes (o-substituted aromatic aldehydes), however, failed to furnish nitroalkanes under these conditions. Also a major solvent effect was observed: the extent of conversion was greater in water than in water-polar 3SnH) as reducing agent. The chemoselective reduction of 2NAs to nitroalkanes was observed accidentally while trying to remove the nitro group of 2NAs in a Bu3SnH-AIBN-water system under microwave conditions. When equimolar quantities of 2NA and Bu3SnH were added to water, microwave irradiation led to nitroalkanes (protic solvent mixtures and the reaction did not occur either in aprotic polar or non-polar solvents. Scheme 1. Microwave assisted chemoselective reduction of 2NAs to nitroalkanes in Bu3SnH-water In Section B, the microwave assisted synthesis of nitroalkanes from nitroalkenes has been described. Equimolar quantities of nitroalkene and Bu Scheme 2 ). The nitroalkenes substituted even by bulky groups at C-1 & C-2 were converted into corresponding nitroalkanes. Hence the drawback of the method described in Section A was overcome by employing nitroalkenes as starting materials. 3SnH in water under microwave irradiation, led to excellent yields of corresponding nitroalkanes (Scheme 2). The nitroalkenes substituted even by bulky groups at C-1 & C-2 were converted into corresponding nitroalkanes. Hence the drawback of the method described in Section A was overcome by employing nitroalkenes as starting materials. Scheme 2. Microwave assisted reduction of nitroalkenes to nitroalkanes in Bu3SnH-water In Section C, the synthesis of nitroalkenes via dehydration of 2NAs in a K Scheme 3 ). Thus, the dehydration of 2NAs has been accomplished under relatively mild conditions. (It was observed that the 2NAs bearing bulky groups underwent the retro-Henry reaction rather than dehydration.) 2CO3-water system has been described. This conversion was accomplished at 0-5 °C in 5-30 minutes, the nitroalkenes being isolated in good yields (Scheme 3). Thus, the dehydration of 2NAs has been accomplished under relatively mild conditions. (It was observed that the 2NAs bearing bulky groups underwent the retro-Henry reaction rather than dehydration.) Scheme 3. Dehydration of 2-NAs in aqueous K2CO3 solution Chapter III describes the chemoselective reduction of ketoaldehydes. This was serendipitously discovered during attempted enantioselective reduction of prochiral ketones using amino acid-NaBH Scheme 4 ). The method provides a mild and efficient route for the chemoselective reduction of aldehydes under aqueous basic conditions. 4-Na2CO3 in water. When equimolar quantities of aldehyde and ketone were added to a solution NaBH4 in aqueous Na2CO3 at ambient temperature, the aldehydes were selectively reduced. Good yields of primary alcohols were generally observed with excellent chemoselectivities. Extension of this study to the selective reduction of ketoaldehydes under the above reaction conditions furnished ketoalcohols in > 70% yields with > 80% chemoselectivities (Scheme 4). The method provides a mild and efficient route for the chemoselective reduction of aldehydes under aqueous basic conditions. Scheme 4. Chemoselective reduction of ketoaldehydes with NaBH4-Na2CO3 in water Chapter IV deals with deprotection of various acetals, thioacetals and tetrahydropyranyl (THP) ethers in hexane under ambient conditions, by employing chloral hydrate as reagent. Chloral hydrate is a crystalline solid with pK2 When a a 9.66.stirred suspension of excess chloral hydrate in hexane was treated with the acetal, thioacetal or THP ether, the corresponding aldehyde, ketone and alcohol were obtained in good to excellent yields (stirred suspension of excess chloral hydrate in hexane was treated with the acetal, thioacetal or THP ether, the corresponding aldehyde, ketone and alcohol were obtained in good to excellent yields (stirred suspension of excess chloral hydrate in hexane was treated with the acetal, thioacetal or THP ether, the corresponding aldehyde, ketone and alcohol were obtained in good to excellent yields ( Scheme 5. Chloral hydrate catalyzed hydrolysis of acetals, thioacetals including THP ethers Part-II:- Mechanistic Studies on Phase Transfer Catalysis and The Hydrophobic Effect Part-II is in two chapters. Chapter V describes a study of the mechanism of the phase transfer catalyzed (PTC) nucleophilic reaction of cyanide ion with alkyl halides in decane ( Scheme 7 ). In the extraction mechanism proposed earlier,3 the PTC forms the mixed species, tributylhexadecylphosphonium cyanide (THPB), which is believed to be more soluble in decane than is the starting cyanide. A problem with this explanation is that the positive free energy of transfer of the cyanide ion from the aqueous to the organic phase, which is unlikely to be offset by solvation energy of the hexadecyl and butyl groups. Scheme 6. Cyanide displacement reaction of 1-chloro octane3 The present studies explore the possibility that the reaction occurs via the formation of aggregates resembling reverse micelles ( Figure 1 ). In these, the hydrocarbon residues point outwards, with the ionic species ensconced in a deeply embedded interior along with a certain number of water molecules. Thus, the ionic species are not only shielded from the organic medium, but also stabilized in a relatively polar micro-environment (largely via dipolar interactions and hydrogen bonding). It is assumed that this stabilization energy surpasses the positive free energy of transfer of cyanide ion from aqueous to the organic phase. Figure 1. Typical representation of cyanide displacement reaction in THPB-decane-water micellar pool In fact, NMR studies on the structural dynamics of THPB in solution offered evidence of aggregation. Also, a correlation between the structures of catalyst and reactant was observed in studies with various other PTC’s. Chapter VI deals with the mechanism of the Diels-Alder reaction (DAR) in water. The concept of the hydrophobic effect (HE)4 and preferential hydrogen bonding of water with the polarized transition state5 have been invoked to explain the apparent acceleration of Diels-Alder reactions in water. The present studies explore the possibility that the highly polar water microenvironment stabilizes the transition state. Semi-quantitative rate studies of DAR involving water soluble reactants indicate that the possible role of solvation and hydrogen bonding on the polarized transition state as the key factor in the rate enhancement of water mediated DAR. The DAR in the presence of a catalytic amount of water along with the organic solvent catalyzed the reaction more efficiently, as compared to the reaction in pure organic solvent. It was also observed that there was a prominent effect of traces of water on the rate in solvent-free conditions. .

Doctor of Philosophy / Department of Chemical Engineering / Larry E. Erickson / Chlorinated solvents are the second most ubiquitous contaminants, next to petroleum hydrocarbons, and many are carcinogens. Tetrachloroethylene or perchloroethene (PCE) has been employed extensively in the dry cleaning industry and carbon tetrachloride (CT) has been used as a fumigant in grain storage facilities. In this work, remediation feasibility studies were conducted by mesocosm experiments; a chamber was divided into six channels and filled with soil, and plants were grown on top. Each channel was fed with contaminated water near the bottom and collected at the outlet, simulating groundwater flow conditions. The contaminants were introduced starting from March 12, 2004. PCE was introduced at a concentration of about 2 mg/L ([similar to]12 [Mu]moles/L) in three channels, two of them with alfalfa plants and the other with grass. CT was introduced at a concentration of about 2 mg/L ([similar to]13 [Mu]moles/L) in the other three channels, two of them with alfalfa plants and the other with grass. After the system had attained steady state, the concentrations of PCE and CT at inlet and outlet were monitored and the amount of PCE and CT disappearing in the saturated zone was studied. Since no degradation products were found at the outlet after about 100 days, one channel-each for PCE and CT (with alfalfa) was made anaerobic by adding one liter of 0.2 % glucose solution. The glucose solution was fed once every month starting from July 1, 2004 and continued until February 2005. From October 1, 2004, one liter of 0.1 % emulsified soy oil methyl esters (SOME) was fed to two other channels (with alfalfa), one exposed to PCE and another exposed to CT. The SOME addition dates were the same as that for glucose. The outlet liquid of the channel fed with PCE and SOME started to contain some of the degradation compounds of PCE; however, the extent of degradation was not as great as that of the glucose fed channel. No degradation compounds were observed in the outlet solution of the channel (grass grown on top) in which no carbon and energy supplements were added. Similar trend was observed in the CT fed channels also. KB-1, a commercially available microbial culture (a consortium of dehalococcoides) that degrades dichloroethene (DCE), was added through the inlet of the PCE fed channels, but this did not lead to sufficient conversion of DCE. Addition of KB-1 at well 3, located approximately in the middle of the channel, had a greater impact in the degradation of DCE, in both glucose and SOME amended channels, compared to addition at the inlet. KB-1 culture added to the channel was active even 155 days later, suggesting that there is sustainable growth of KB-1 when provided with suitable conditions and substrates. A pilot field study was conducted for remediation of a tetrachloroethylene (PCE) contaminated site at Manhattan, KS. The aquifer in the pilot study area has two distinct zones, termed shallow zone and deep zone, with groundwater velocities of about 0.3 m/day and 0.1 m/day. Prior to the pilot study, PCE concentration in groundwater at the pilot study area was about 15 mg/L (ppm) in the deep zone and 1 mg/L in the shallow zone. Nutrient solution comprising soy oil methyl esters (SOME), lactate, yeast extract and glucose was added in the pilot study area for biostimulation, on August 18, 2005. Potassium bromide (KBr) was added to the nutrient solution as a tracer. PCE was converted to DCE under these conditions. To carry out complete degradation of PCE, KB-1, a consortium of Dehalococcoides, and a second dose of nutrient solution were added on October 13, 2005. After addition of KB-1, both PCE and DCE concentrations decreased. Nutrients were again injected on March 3, 2006 (with KBr) and on August 1, 2006. The total chlorinated ethenes (CEs) have decreased by about 80 % in the pilot study area due to bioremediation. Biodegradation of CEs continued for a long time (several months) after the addition of nutrients. The insoluble SOME may be retained at the feeding area and provide a long time source of electron donors. Biostimulation and bioaugmentation of PCE contaminated soil and groundwater was evaluated in the laboratory and this technique was implemented successfully in the pilot field study. Modeling of the tracer study was performed using an advection-dispersion equation (ADE) and traditional residence time distribution (RTD) methods. The dispersion coefficient, groundwater velocity and hydraulic conductivity were estimated from the experimental data. The groundwater velocities vary from 1.5 cm/d to 10 cm/d in the deep zone and 15 cm/d to 40 cm/d in the shallow zone. The velocities estimated from the 2004 tracer study and 2005 tracer study were higher compared to the velocity estimated from the 2006 tracer study, most likely because of microbial growth and product formation that reduced the hydraulic conductivity. Based on data collected from several wells the hydrologic parameter values obtained from tracer studies appear to vary spatially.

<p>Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.</p><p>The aim of the study has been to investigate whether the CAH-concentration in tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons. The aim has also been to gain an understanding of the uptake process, as well as to identify the limitations of the method and important issues to consider when sampling.</p><p>Trees were sampled in March and June on Helgö 1:25, 1:26 in Växjö, Småland. Metal degreasing earlier conducted at this site has lead to the CAH contamination of soil and groundwater (PCE, TEC c-DACE). Mostly PCE, TCE, and chloroform were detected in tree cores. The CAH concentration was higher in June. Using the sum of PCE+TCE+c-DCE in trees to delineate the spread gave a result that was quite consistent with a delination done based on groundwater sampling.</p><p>The uptake of CAH by trees is governed by the uptake of water at the root. The water usage, together with the origin of the water used is important for the ability of the tree to take up CAH. The CAH concentration within trees is also dependent on the chemical properties of the compound (Log kow, solubility etc), the concentration of the compound in the soil as well as degradation processeses. The position and height of sampling in the trees, tree species as well as tree size are important factors to consider when sampling. Sampling during summer is preferred when the concentration of CAH in trees is likely to be higher.</p><p>The analysis of CAH in tree cores has potential to be used as a screening tool in soil investigations under Swedish conditions. It is a cheap and easy to use method, which would be a good complement to other investigative measures. However, an increased understanding of the processes involved, together with more analysis are needed., as this is a new method.</p> / <p>Klorerade lösningsmedel (CAH) användes i stor omfattning som bl a kemtvättmedel och avfettningsmedel tills dess att deras toxiska egenskaper blev kända. Perkloretylen (PCE) används än idag som kemtvättmedel. CAH återfinns ofta i markmiljö på de platser där de tidigare använts. Analys av CAH-koncentration i trädkärnor har uppmärksammats som en billig och effektiv metod för att översiktligt bedöma utbredningen av dessa föroreningar. Metoden har inte tidigare använts i Sverige.</p><p>Syftet med detta examensarbete är att undersöka om trädprovtagning kan användas för att bedöma utbredningen av föroreningar i markmiljö under svenska förhållanden vid olika årstider.</p><p>Analyserade CAH-halter i träd har jämförts med tidigare registrerade halter av CAH i grundvatten. Syftet har också varit att beskriva CAH-upptaget i träd, undersöka metodens begränsningar samt att sammanfatta viktiga aspekter vid provtagning.</p><p>Provtagningar av träd har genomförts under mars och juni på fastigheterna Helgö 1:25 och 1:26 i Växjö, där tidigare metallavfettning har medfört att mark och grundvattnet förorenats av CAH; perkloretylen (PCE), trikloretylen (TCE) och nedbrytningsprodukten dikloretylen (c1,2-DCE). Vid analys av trädkärnor detekterades främst PCE, TCE samt TCM (kloroform). Koncentrationen av CAH var högre i juni. Halten PCE+TCE+c-DCE i trädproverna gav en översiktlig bild av föroreningssituationen som överensstämde väl med de grundvattenprover som tidigare tagits på fastigheten.</p><p>CAH tas upp i vattenlöst fas vid trädens rötter. Trädets vattenbehov och vilket vatten det utnyttjar är därför viktigt för dess möjlighet att ta upp CAH. Ämnets kemiska egenskaper (log kow, flyktighet, mm.), samt förekomst och nedbrytning påverkar den halt som registreras i trädet. Vid provtagning bör provtagningspunkternas höjd över marken och position, trädart samt trädstorlek beaktas. Provtagning under sommaren är att föredra eftersom halterna då är högre.</p><p>Jämförelsen med grundvattenprovtagning visar att metoden har potential att användas i Sverige för att bedöma utbredningen av en CAH-förorening i markmiljö. Den är enkel att använda och kan vara ett alternativ på platser där konventionella metoder är svåra att genomföra. En ökad förståelse för involverade processer, samt utökade undersökningar av metoden är nödvändiga då metoden är ny.</p>

Très récemment, les solvants de type « mélanges eutectiques profonds (MEP)» ont été décrits comme une alternative sérieuse et économiquement plus réaliste aux liquides ioniques. En effet, ces solvants qui consistent en un mélange d'un sel organique (ammonium ou phosphonium) et d'un donneur de liaison hydrogène peuvent également être liquides à température ambiante, non volatils et présentant une excellente stabilité thermique. De plus, contrairement aux liquides ioniques, ces nouveaux solvants sont très facilement préparés et leur innocuité ainsi que leur bonne biodégradabilité sont sensiblement améliorées. Dans le domaine des procédés enzymatiques, si la biocatalyse en milieu liquide ionique est très documentée, il n'existe que très peu de publications décrivant des réactions de biotransformation en MEP. Concernant les lipases en particulier, outre leurs applications dans le biofaçonnement des corps gras, ces enzymes sont également utilisées dans des réactions dites de lipophilisation pour la synthèse de nouvelles molécules à haute valeur ajoutée (tensioactifs, antioxydant lipophilisés). Au travers cette étude nous nous sommes investis à tester le potentiel des MEP en tant que nouveaux milieux réactionnels « verts » pour la synthèse lipasique. Ce travail n'a pas eu comme objectif de faire l'éloge de ces solvants pour leur utilisation dans le domaine de la biocatalyse, mais surtout d'évaluer leur capacité à favoriser ou non des synthèses lipasiques. Par ailleurs, nous nous sommes engagés à essayer de comprendre, d'un point de vue fondamental, l'organisation supramoléculaire de ce type de milieux pour déterminer les paramètres qui influencent le plus la réactivité et la stabilité enzymatique dans ce type d'environnement. Les variations des conditions réactionnelles (solvants et biocatalyseurs) ont permis de mettre en évidence la très nette supériorité de deux MEP (Chlorure de cholinium:Urée et Chlorure de cholinium:glycérol) pour la réalisation de réactions d'alcoolyses biocatalysées par la lipase B de Candida antarctica. Toutefois, les résultats ont montré que les réactions de biotransformations de composés phénoliques dans ces MEP sont extrêmement difficiles à réaliser sans l'addition d'eau. De profondes études (pH, activité thermodynamique de l'eau, activité et stabilité de la lipase, composition du solvant, etc.) réalisées sur des mélanges du type MEP-eau ont permis de finement adapter les conditions de réaction pour optimiser la catalyse enzymatique dans ce type de solvant. Compte tenu des difficultés rencontrées pour la lipophilisation de composés phénoliques, nous sommes toutefois parvenus à synthétiser toute une gamme de dérivés lipophiles d'acides férulique et coumarique de C4 à C16 (chaîne aliphatique) avec des rendements élevés. / With the emergence of the green chemistry concept in the 90s, many studies have been dedicated to the discovery of new reactions media both suitable and efficient for chemical/enzyme catalysis. Up to now, the main efforts have focused on the development of ionic liquids. However, recently a novel class of solvent called "deep eutectic mixtures (DES)", have been described as a serious alternative and economically stronger than ionic liquids. Such solvents are formed by mixing an organic salt (ammonium or phosphonium) with a hydrogen-bond donor. Just like ionic liquid, DES may also be liquid at room temperature, non-volatile and have excellent thermal stability. However, unlike most ionic liquids, these new solvents are biodegradable, inexpensive, and very easy to prepare. In the field of biocatalysis, whereas the studies in ionic liquid are deeply documented, the published papers describing biotransformation reactions in DES are very low, especially in lipase-catalyzed processing, where these enzymes may be used in so-called "lipophilisation reactions", for the synthesis of new molecules with high added value (surfactants or lipophilized antioxidants).The main objective of this work was to assess and test the potential of DES as new "green" reaction media for lipase-catalyzed synthesis. On a fundamental point of view, this study provides valuable information to understand how the different components involved in these mixtures could contribute to their functional properties in order to enhance their use in various applications. Changes in reaction conditions (solvents and biocatalysts) allowed us to highlight the clear superiority of two DES (chloride cholinium:Urea and chloride cholinium:glycerol) to carry out lipase-catalyzed reactions using the lipase B from Candida antarctica as biocatalyst. However, our results showed that the biotransformations of dissolved substrates (such as phenolic compounds) in DES are extremely difficult to achieve without the addition of water. Studying DES-water mixtures (pH, thermodynamic activity of water, activity and stability of lipase, mixtures composition, etc ...) we were able to fine-tune the reaction conditions to optimize the performance of the lipasic catalysis. Thus, given the difficulties encountered when performing lipase-catalyzed reactions with substrates of two different polarities, it was still possible to synthesize high yields of a full range of lipophilic derivatives of ferulic and coumaric acids from C4 to C16 (aliphatic chain).

Determinar o conteúdo dos lipídeos presentes nos tecidos animais nem sempre resulta em uma resposta com precisão, devido á pouca disponibilidade de métodos adequados para a extração e determinação quantitativa destes lipídeos. A extração de lipídeos de matrizes complexas, como o pescado, por meio dos métodos tradicionais de Bligh & Dyer e Folch normalmente utilizam solventes com elevada toxicidade, cujos resíduos podem gerar um elevado impacto ambiental. A chamada segurança química está diretamente ligada à qualidade de vida e alerta para as questões de controle e prevenção dos efeitos adversos dos solventes ao ser humano e ao ambiente, compreendendo desde a extração, uso e descarte desses e seus resíduos. Portanto, o objetivo deste trabalho foi estudar as condições de extração de lipídeos totais de resíduos do processamento de tilápias, visando à proposição de um método alternativo que garanta uma eficiência tão satisfatória quanto as obtidas pelos métodos tradicionais de extração. Ademais, foi desenvolvido um método de extração mais seguro ao ambiente utilizando solventes menos tóxicos que os propostos pelo método de Bligh &Dyer, por meio da aplicação experimental de um diagrama de fases hexano- etanol- água. Após a identificação da melhor combinação de solventes, os extratos obtidos com hexano- etanol apresentaram rendimento eficiente em lipídeos totais e capacidade de extrair os componentes lipídicos polares e apolares das amostras analisadas. O melhor aproveitamento dos lipídeos a serem extraídos da matriz resíduos de peixes na proporção em massa de solvente hexano: etanol: água, foram da solução 1 (1: 7: 1,375) para a carcaça, da solução 2 (1: 2,5: 1,1875) para a cabeça e da solução 4 (4: 1: 4,375) para as vísceras totalizando 14,13%, 14,69 e 47,63% de teor de lipídeos, respectivamente. Logo, ao buscar sistemas de solventes alternativos ao clorofórmio - metanol, para extrair lipídeos de resíduos do processamento de tilápias, foi possível identificar as melhores proporções de hexano: etanol: água como substituição do método tradicional proposto por Bligh & Dyer (1959). / The total lipid content of animal tissues is not always accurately measured due to the lack of adequate methods for lipid extraction and quantitative determination of tissue fat. The extraction of lipids from complex matrices, such as fish, using the traditional methods proposed by Bligh &Dyer and Folch usually, employs solvents with high toxicity, whose residues can generate a high environmental impact. The chemical safety concern nowadays is directly linked to quality of life involving control and prevention of adverse effects of solvents to humans and the environment, ranging from the extraction, use and disposal of these and their residues. Moreover, the procedures of sample preparation, the sample: solvent ratio, the proportion of solvents applied, and the order of addition of solvents during the experiment are not standardized in these methods. Therefore, the present study aimed to assess the extraction conditions of total lipids from fish processing residues, and thus propose a standardized method which ensures a maximum efficiency in lipid extraction. Furthermore, a more environmental-friendly oil extraction method using less toxic solvents than those proposed by the Bligh & Dyer method (i.e. using the hexane-ethanol-water phase diagram) was developed. After identifying the best combination of solvents, the extracts obtained with hexane- ethanol showed effective yield on total lipids and the ability to extract the polar lipid components and nonpolar of the samples. The best use of lipids to be extracted from fish waste matrix, were the solution 1 (1: 7: 1,375) for the carcass of solution 2 (1: 2,5: 1,1875) for the head and the solution 4 (4: 1: 4,375) for the viscera totaling 14,13%, 14,69% and 47,63%(4: 1: 4,375) respectively. Therefore, to seek alternative solvent systems chloroform - methanol to extract lipids of tilapia processing waste, it was possible to identify the best proportions of hexane: ethanol: water as replacing the traditional method proposed by Bligh & Dyer (1959).