Achour S.,University of Monastir |
Khelifi E.,CNRS Institute of Earth Sciences |
Attia Y.,University of Monastir |
Ferjani E.,Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria |
Noureddine Hellal A.,University of Monastir
Journal of Food Science | Year: 2012
Thymus capitatus is a Mediterranean plant characterized by its antioxidant polyphenols of which the most known are the carnosic and rosmarinic acids. In this way, this study aims to concentrate these acids by membrane processes. The thyme essential oil composition was established by capillary GC-MS and 27 components were identified representing 98.93%± 1.97% of total oils. The antioxidant test for permeate and retentate of methanolic and aqueous extract were determined using 3 types of membranes. The results showed that the synthetic NF membrane is able to trap and concentrate phenolic compounds in the retentate much better than the NF commercial and UF synthetic membrane. The results of the total phenolic content (TPC) showed a significant value of the polyphenol content present in the aqueous extract with 175.53 mg Gallic Acid Equivalents (GAE)/g of extract. The spectrum of the aqueous extract of Thymus capitatus showed the presence of 3 visible peaks, the 1st one at 217 nm corresponding to the carnosic acid, the 2nd one at 277 nm for essential oils, and the last one at 326 nm attributed to the rosmarinic acid. The commercial membrane NF-DK succeeded to concentrate rosmarinic acid and can be considered as a stage towards the concentration of this product with a high added value. © 2012 Institute of Food Technologists ®.
Paraschiv M.,Romanian National Institute for Research and Development for Biological Sciences |
Paraschiv M.,Polytechnic University of Bucharest |
Kuncser R.,Romanian RandD Institute for Gas Turbines COMOTI |
Kordoghli S.,Ecole des Mines de Nantes |
And 4 more authors.
IREC 2016 - 7th International Renewable Energy Congress | Year: 2016
In this paper the products obtained through thermochemical processing of several polymer-based wastes are characterised. The influence of chemical composition of raw materials on the characteristics of obtained products has been investigated by using fixed bed reactor. The aim of this work is to identify the best use of products recovered after pyrolysis of plastic wastes collected from chemical and biochemical laboratories. This work is developed in a laboratory bench installation design to perform O2-free processing at atmospheric pressure. The process parameters such as pyrolysis temperature and adapted heating rate have been determined through the transposition of thermal and kinetic information provided by thermogravimetric analysis (TGA). Gas-chromatography techniques have been used to identify the chemical composition of gases (GC/TCD) and liquids (GC/FID-MS). It was established that polymer wastes can led to a valuable liquid products, with encouraging energetic properties that allow their blending with fuels currently used without altering the performances of burning devices. © 2016 IEEE.
Slimane B.B.,Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria |
Ezzine O.,Institute National Of Recherches En Genie Rural |
Dhahri S.,Institute National Of Recherches En Genie Rural |
Jamaa M.L.,Institute National Of Recherches En Genie Rural
Biological research | Year: 2014
BACKGROUND: Essential oils extracted from aromatic and medicinal plants have many biological properties and are therefore an alternative to the use of synthetic products. The chemical composition of essential oils from two medicinal plants (Eucalyptus globulus and E. lehmannii) was determined and, their insecticidal effects on the third and fourth larval stages of Orgyia trigotephras were assessed.RESULTS: Larvae were collected from Jebel Abderrahmane (North-East of Tunisia), conserved in groups of 50/box (21 × 10 × 10 cm) at a temperature of 25°C. Larvae were tested for larvicidal activities of essential oils. Each oil was diluted in ethanol (96%) to prepare 3 test solutions (S1 = 0.05%, S2 = 0.10% and S3 = 0.50%). Essential oils were used for contact, ingestion and Olfactory actions and compared to reference products (Bacillus thuringiensis and Decis). Olfactory action of essential oils shows that larvae mortality is higher than contact action, lower than ingestion action. MTM and FTM of S3 of E. lehmannii were respectively 1 h 32 min and 1 h 39 min are higher than those of E. globulus (MTM = 51 min and FTM = 1 h 22 min 34 sec). Contact action of E. lehmannii oil shows low insecticidal activity compared to E. globulus. MTM are respectively (1 min 52 sec and 1 min 7 sec), FTM are (2 min 38 sec, 1 min 39 sec), are the shortest recorded for S3, on the third stage of larvae. The fourth stage of larvae, MTM are (2 min 20 sec and 2 min 9 sec), FTM are (3 min 25 sec, 3 min 19 sec). Ingestion action of essential oils is longer than the contact action, since the time of death exceeds 60 minutes for all species.CONCLUSION: Results shows that essential oils have a toxic action on nerves leading to a disruption of vital system of insects. High toxic properties make these plant-derived compounds suitable for incorporation in integrated pest management programs.
Ben Moussa A.,Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria |
Mzali H.,CNRS Georesources lab |
Zouari K.,University of Sfax |
Hezzi H.,Commissariat Regional au Developpement Agricole
Quaternary International | Year: 2014
The major ion hydrochemistry and environmental isotope composition (18O, 2H) of the Tazoghrane shallow groundwaters were investigated to identify the sources and processes that affect the groundwater composition. The Quaternary shallow aquifer of Tazoghrane represents one of the most important aquifers in the Cap Bon peninsula. Groundwater from this aquifer is classified into two water types: Ca-SO4-Cl and Na-Cl. The groundwater composition is largely controlled by the water-rock interaction, particularly the dissolution of evaporate minerals and the ion exchange process. Elevated content of nitrates indicates that agricultural activities are probably the most significant anthropogenic sources of nitrogen contamination. The stable isotopic signatures reveal two water groups. Non-evaporated waters, which are distinguished by depleted d18O and d2H contents, indicate the significant recharge by modern rainfall from Mediterranean air masses. Evaporated waters that are characterized by relatively enriched d18O and d2H contents indicate an important component of recharge by return flow of irrigation waters. © 2014 Elsevier Ltd and INQUA.
Kordoghli S.,Ecole des Mines de Nantes |
Kordoghli S.,University of Monastir |
Paraschiv M.,INCDSB |
Tazerout M.,Ecole des Mines de Nantes |
Zagrouba F.,Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria
2015 6th International Renewable Energy Congress, IREC 2015 | Year: 2015
Thinking on environmental hazards, images of chemicals in waters, or air pollution coming out of industrial furnaces are most often seen. There are some hazards that are overlooked and one of them is scrap tires. Without a good management, scrap tires treatment can threaten not only our environment, but the public health as well. For instant, run-off from scrap tire fires can contaminate groundwater and surface water, and scrap tire sites are an ideal habitat for the breeding of insects carrying disease. In this paper we present an experimental approach on understanding and managing the environmental hazards of co-products resulted during energy recovery processes applied on scrap tyres. As tyre combustion faces serious problems related to harmful emissions, pyrolysis appears as a process that allows the management of toxic compounds. The experimental data were used to highlight the influence of textile and metal tyre compounds and provided worthy and substantive information on the issues to conduct and manage the thermochemical process in order to maximize the interest product yield. Thus, for the reactions occurs during pyrolysis and combustion of tyres organic matters the main intensive degradation thermal ranges have been established. The work was carried out by coupling thermogravimetric analysis (TGA) of tyre samples with bench scale reactor in order to identify the relationships between thermochemical behaviour and products distribution. TGA results afford the study of the kinetics parameters while the laboratory facilities allow the comprehension of tyres behaviours in real conditions. The processing temperature was limited at 700°C and the measures focused on the mass balance determination and gaseous products analysis. It was found that the three obtained products have a good energetic potential: the solid (20-32 MJ/kg), the liquid (41-43 MJ/kg) and the gas (32-36 MJ/m3). Nevertheless, the liquid need to be upgrading in order to be used as Diesel-like fuel and gases should be treated to remove sulphur compounds. With this purpose some catalysts, known for their ability to increase gaseous fraction have been studied in TGA and an important shift of degradation peaks was identified and discussed. © 2015 IEEE.