Effet des macrophytes aquatiques sur le traitement d’eau contaminée à l’ACC et au PCP

L’objectif principal de ce projet est d’évaluer le potentiel d’un système de marais filtrants combinés pour le traitement d’un lixiviat contaminé aux agents de préservations du bois - l’arséniate de cuivre chromaté (ACC) et le pentachlorophénol (PCP) - en portant une attention particulière au rôle des plantes. Pour ce faire, une expérience en pot faisant varier la concentration d’exposition de quatre espèces de macrophyte (Typha angustifolia, Phalaris arundinacea, Phragmites australis americanus et Phragmites australis australis) a été effectuée. Le suivi de quatre marais filtrants à écoulement horizontal sous-surfacique, plantés d’une des quatre espèces de macrophyte et d’un bassin planté de saules (Salix Miyabeana SX67) a également été réalisé. La résistance des plantes au milieu contaminé, la capacité de bioaccumulation des macrophytes et les efficacités de traitement des différents systèmes ont été analysés. Nos résultats montrent que la concentration d’exposition n’influence pas la capacité des plantes à croître en milieu contaminé. Par contre, il existe une relation dose-réponse entre la concentration d’exposition et la capacité de bioaccumulation des macrophytes. Les quatre marais pilotes ont tous des efficacités de traitements supérieures à 55% en 2013 et 82% en 2014 pour les contaminants à l’étude. Le bassin de saule a la capacité théorique d’évapotranspirer jusqu’à 1200 L par jour. De plus, ses efficacités de traitements sont supérieures à 59% pour tous les composés à l’étude. L’utilisation de marais filtrants pour le traitement d’un lixiviat contaminé aux agents de préservations du bois est donc une alternative intéressante aux méthodes de traitement conventionnel.

2(3H)-Furanones and related substrates: Synthetic strategies and selectivity profile in their reactivity

The synthesis and reactions of simple derivatives of 2(3H)- and 3(2H)furanones have attracted considerable attention in recent years, primarily in connection with development of routes to antitumor agents that contain this ring as central structural unit. They also serve as useful synthetic building blocks for lactones and furans and are the precursors of a wide variety of biologically important heterocyclic systems. Although a number of syntheses of furanones were known they were in many cases limited to specific substitution pattems. The development of altemative strategies for the preparation of these heterocycles is therefore of considerable importance or continues to be a challenge.We propose to develop new and general approaches to the synthesis of furanone ring systems from simple and readily available starting materials since we were interested in examining their rich photochemistry. The photochemical reactivity of Beta,gama-unsaturated lactams and lactones is a subject of current interest. Some of the prominent photoreaction pathways of unsaturated lactones include decarbonylation, solvent addition to double bonds, decarboxylation, migration of aryl substituents and dimerisation. lt was reported earlier that the critical requirement for clean photochemical cleavage of the acyl-oxygen bond is the presence ofa double bond adjacent to the ether oxygen and 2(3H)-furanones possessing this structural requirement undergo facile decarbonylation. But related phenanthrofuranones are isolated as photostable end products upon irradiation. Hence we propose to synthesis a few phenanthro-2(3H)-furanones to study the effect of a radical stabilising group at 3-position of furanone ring on photolysis. To explore the tripletmediated transformations of 2(3H)-furanones in polar and nonpolar solvents a few 3,3-bis(4-chlorophenyl)-5-aryl-3H-furan-2-ones and 3,3-di(p-tolyl)-5-aryl- 3H-furan-2-ones were synthesised from the corresponding dibenzoylstyrene precursors by neat thermolysis. Our aim was to study the nature of intermediates involved in these transformations.We also explored the possibility of developing a new and general approach to the synthesis of 3(2H)-furanones from simple and readily available starting materials since such general procedures are not available. The protocol developed by us employs readily available phenanthrenequinone and various 4-substituted acetophenones as starting materials and provides easy access to the required 3(2H)-furanone targets. These furanone derivatives have immense potential for further investigations .We also aimed the synthesis of a few dibenzoylalkene-type systems such as acenaphthenone-2—ylidene ketones and phenanthrenone-9-ylidene ketones. These systems were expected to undergo thermal rearrangement to give furanones and spirofuranones. Also these systems can be categorised as quinonemethides which are valuable synthetic intermediates.

Synthesis and Biological Evaluation of New Ozonides with Improved Plant Growth Regulatory Activity

The iron oxyallyl carbocation generated from 2,7-dibromocycloheptanone was induced to undergo [4 + 3] cycloaddition reactions with various furans, affording a series of 12-oxatricyclo-[4.4.1.1(2,5)]-dodec-3-en-11-one adducts. Similar methodology was used to prepare two additional cycloadducts using menthofuran and two homologous aliphatic dibromoketones. Dipolar cycloaddition of ozone to the adducts afforded the corresponding secondary ozonides (i.e., 1,2,4-trioxolanes) in variable yields. Ozonides were investigated by quantum mechanics at the B3LYP/6-31+G* level to study structural features including close contacts which may be responsible for enhancing ozonide stability. The effect of these ozonides and their corresponding precursor cycloadducts upon radicle growth of both Sorghum bicolor and Cucumis sativus was evaluated at 5.0 x 10(-4) mol L-1. The most active cycloadducts and ozonides were also evaluated against the weed species Ipomoea grandifolia and Brachiaria decumbens, and the results are discussed. Compared to ozonides previously synthesized in our laboratory, the new ozonides described herein present improved plant growth regulatory activity.

A study of the aroma of fried bacon and fried pork loin

Aroma compounds in the headspace volatiles of fried bacon and fried pork loin were identified. The concentrations of volatiles in bacon were much lower than those in pork loin, except for nitrogen compounds. It is likely that these differences were caused by the presence of nitrite in bacon. Characteristic aromas for fried bacon, described variously as bacon-, fried meat-, roast meat- and cooked meat-like, were found through olfactory testing. These aromas were not present in the pork loin samples. Compounds such as pyrazines, pyridines and furans are thought to be responsible for these meaty aromas. (C) 2004 Society of Chemical Industry.

Volatile compounds produced by the probiotic strain Lactobacillus plantarum NCIMB 8826 in cereal-based substrates

The production of volatile compounds by the probiotic strain, Lactobacillus plantarum NCIMB 8826, in cereal-based media (oat, wheat. barley and malt) was investigated. Sixty compounds, including fatty acids and their esters, amides, alcohols, aldehydes, aromatic hydrocarbons, furans, ketones, peroxides and pyrans, were identified. L. plantarum significantly changed the aroma profile of the four cereal broths. and each substrate showed a specific volatiles profile. Oat and barley media were the substrates more influenced by the fermentation process. The most abundant volatiles detected in oat, wheat, barley and malt were oleic acid, linoleic acid. acetic acid, and 5-hydroxymethylfurfural, respectively. Analysis of these products confirmed the heterofermentative pathway of L plantarum. Maillard compounds were not detected during sterilisation and fermentation. This study is the first to report the volatile composition of probiotic drinks produce with non-supplemented cereal-based media and the results obtained could contribute to the development of new non-dairy probiotic formulations. (C) 2009 Elsevier Ltd. All rights reserved.

Sensory and instrumental analyses of volatiles generated during the extrusion cooking of oat flours

Three batches of oats were extruded under four combinations of process temperature (150 or 180 °C) and process moisture (14.5 and 18%). Two of the extrudates were evaluated by a sensory panel, and three were analyzed by GC-MS. Maillard reaction products, such as pyrazines, pyrroles, furans, and sulfur-containing compounds, were found in the most severely processed extrudates (high-temperature, low-moisture). These extrudates were also described by the assessors as having toasted cereal attributes. Lipid degradation products, such as alkanals, 2-alkenals, and 2,4-alkadienals, were found at much higher levels in the extrudates of the oat flour that had been debranned. It contained lower protein and fiber levels than the others and showed increased lipase activity. Extrudates from these samples also had significantly lower levels of Maillard reaction products that correlated, in the sensory analysis, with terms such as stale oil and oatmeal. Linoleic acid was added to a fourth oat flour to simulate the result of increased lipase activity, and GC-MS analysis showed both an increase in lipid degradation products and a decrease in Maillard reaction products.

Occupational airborne contamination in South Brazil: 2. Oxidative stress detected in the blood of workers of incineration of hospital residues

One of the most useful methods for elimination of solid residues of health services (SRHS) is incineration. However, it also provokes the emission of several hazardous air pollutants such as heavy metals, furans and dioxins, which produce reactive oxygen species and oxidative stress. The present study, which is parallel to an accompanied paper (Avila Jr. et al., this issue), investigated several enzymatic and non-enzymatic biomarkers of oxidative stress in the blood (contents of vitamin E, lipoperoxidation = TBARS, reduced glutathione = GSH, oxidized glutathione = GSSG, and activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in three different groups (n = 20 each) exposed to airborne contamination associated with incineration of SRHS: workers directly (ca. 100 m from the incinerator) and indirectly exposed (residents living ca. 5 km the incineration site), and controls (non-exposed subjects). TBARS and GSSG levels were increased whilst GSH, TG and alpha-tocopherol contents were decreased in workers and residents compared to controls. Increased GST and CAT activities and decreased GPx activities were detected in exposed subjects compared to controls, while GR did not show any difference among the groups. In conclusion, subjects directly or indirectly exposed to SRHS are facing an oxidative insult and health risk regarding fly ashes contamination from SRHS incineration.

Effect of the estufagem process on the chemical constituents of Madeira wines

Madeira wine is a product of well-established reputation, whose aroma and flavour is the result of unique combinations. Particularly, its maturation may include estufagem, wherein wine is usually heated at 45 °C for three months. During this period, several chemical changes may occur, so it is essential to assess its impact on the wine. In this sense, the main objective of the thesis was to evaluate the effect estufagem on the chemical constituents of Madeira wine, specifically on those molecules potentially important in the development of its typical features. Firstly, analytical methodologies capable of determining the target compounds, combining precision and reproducibility to execution effectiveness, were developed. Then various monovarietal Madeira wines were analysed during estufagem under standard and overheating conditions in order to assess its effect. The following compounds were evaluated: furans, amino acids, biogenic amines, polyphenols, organic acids and volatile compounds. In addition, the total polyphenolic composition, the antioxidant potential and the colour of these wines were also evaluated. The results show that most constituents change due to the heating process. Particularly, the heating promotes the development of 5-hydroxymethylfurfural (HMF) in sweet wines submitted to estufagem at higher temperatures. Moreover, estufagem provides the decrease of most amino acids, suggesting their involvement in the formation of the bouquet of these wines. Regarding the total polyphenol content and antioxidant potential of these wines they do not seem to be greatly affected by the heating step, however most monomeric polyphenols decrease during this process. The thermal processing of Madeira wines favours the development of the volatile composition, especially of volatiles usually reported as typical aromas of Madeira wines. Finally, it was demonstrated that the thermal degradation of sugars, especially of fructose, promotes the emergence of volatile compounds identified in baked wines.

Preparação e caracterização de catalisadores à base de titânio suportado em MCM-41 para produção de compostos oxigenados através da pirólise catalítica do capim elefante

In recent years, the area of advanced materials has been considerably, especially when it comes to materials for industrial use, such as is the case with structured porosity of catalysts suitable for catalytic processes. The use of catalysts combined with the fast pyrolysis process is an alternative to the oxygenate production of high added value, because, in addition to increasing the yield and quality of products, allows you to manipulate the selectivity to a product of interest, and therefore allows greater control over the characteristics of the final product. Based on these arguments, in this work were prepared titanium catalysts supported on MCM-41 for use in catalytic pyrolysis of biomass, called elephant grass. The reactions of pyrolysis of biomass were performed in a micro pyrolyzer, Py-5200, coupled to GC / MS, the company CDS Corporation, headquartered in the United States. The catalysts Ti-MCM-41 in different molar ratios were characterized by XRD, TG / DTG, FT-IR, SEM, XRF, UV-visible adsorption of nitrogen and the distribution of particle diameter and specific surface area measurement by the BET method. From the catalytic tests it was observed that the catalysts synthesized showed good results for the pyrolysis reaction.The main products were obtained a higher yield of aldehydes, ketones and furan. It was observed that the best reactivity is a direct function of the ratio Si/Ti, nature and concentration of the active species on mesoporous supports. Among the catalysts Ti-MCM-41 (molar ratio Si / Ti = 25 and 50), the ratio Si / Ti = 25 (400 ° C and 600 ° C) favored the cracking of oxygenates such as acids , aldehydes, ketones, furans and esters. Already the sample ratio Si / Ti = 50 had the highest yield of aromatic oxygenates

Communiols E-H: New polyketide metabolites from the coprophilous fungus Podospora communis

Communiols E-H (1-4), four new polyketide-derived natural products containing furanocyclopentane, furanocyclopentene, cyclopentene, or γ-lactone moieties, have been isolated from two geographically distinct isolates of the coprophilous fungus Podospora communis. The structures of these compounds were determined by analysis of NMR and MS data. © 2005 American Chemical Society and American Society of Pharmacognosy.

Estudo do comportamento térmico do inseticida HCH com perspectivas para aplicação em descontaminação térmica de solos

Pós-graduação em Química - IBILCE

Redução das emissões de gases efeito estufa no processo de fabricação do sinter

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pré-tratamento do bagaço de cana-de-açúcar, hidrólise e sua caracterização química e estrutural, visando a produção de etanol de segunda geração

Pós-graduação em Biotecnologia - IQ

Operational and environmental assessment on the use of charcoal in iron ore sinter production

A study was carried out into the use of charcoal as a supplementary fuel in the iron-ore sintering process. The primary fuel was coke breeze and anthracite with 0, 10, 25, 50 and 100% replacement of the energy input with charcoal to produce sinter. This was achieved by considering the carbon content of each fuel and its corresponding participation on fuel blending, in order to have the same carbon input in each test run. An extensive analysis of the environmental impact was carried out regarding the atmospheric pollutants characterization (dust, sulphur dioxide, nitrogen oxides, carbon monoxide, carbon dioxide, methane, total hydrocarbons, and dioxins and furans). Experimental results indicate that fuel blending where 50% of the heat input was provided by charcoal may be comparable with those using 100% coke, under normal sintering conditions, and may result in a 50% reduction on greenhouse gas emission. It was also observed that while dust, methane and hydrocarbons emissions increased, the total dioxins and furans, expressed as polychlorinated dibenzodioxins/furans, decreased approximately 50% when compared with operation with 100% coke.

Pré-tratamento do bagaço de cana-de-açúcar, hidrólise e sua caracterização química e estrutural, visando a produção de etanol de segunda geração

Pós-graduação em Biotecnologia - IQ