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Limam I.,National Institute of Research and Physicochemical Analysis | Limam I.,University of Carthage | Driss M.R.,University of Carthage
International Journal of Environmental Science and Technology

An off-line solid-phase extraction procedure followed by high-performance liquid chromatography with ultraviolet detection for the determination of 16 priority polycyclic aromatic hydrocarbon pollutants in aqueous matrices was described. Diverse aspects determining extraction efficiency such as packing type (disk or cartridge), elution solvents and addition of organic modifiers to the sample were evaluated. Elution with acetonitrile yields the highest recoveries. Rinsing the sample bottle with acetonitrile and combining the rinse with the sample extract avoids the adsorption of polycyclic aromatic hydrocarbons on the walls of the water containers. The use of isopropanol or methanol 10 % (V/V) was the most appropriate amount for the enrichment of 2- to 6-ring aromatic compounds only on C18 cartridge. The recoveries for all studied polycyclic aromatic hydrocarbons are ranged from 71.4 to 95.2 % for a treated water samples of 500 mL. The proposed method gives very low detection limits (subnanograms per liter) and it has been applied to drinking water, surface water and industrial effluent (oil refinery) samples with good results. © 2013 Islamic Azad University (IAU). Source

Mhadhbi M.,National Institute of Research and Physicochemical Analysis | Sunolb J.J.,University of Girona | Khitouni M.,University of Sfax
Physics Procedia

A nanocrystalline Fe(Al) solid solution was prepared by mechanical alloying (MA) of Fe and Al elemental powders using a planetary ball mill under argon atmosphere. The powder milled for 20 h was annealed at 250, 550 and 650 °C for 1 h. The phase transformations and structural changes occurring in the studied material during mechanical alloying and during subsequent annealing were investigated by X-ray diffraction. The morphology of the powders after MA was examined via SEM and TEM. © 2013 The Authors. Published by Elsevier B.V. Source

Touati B.,National Institute of Agronomical Research of Tunisia | Touati B.,Tunisian National Institute of Applied Sciences and Technology | Chograni H.,Tunisian National Institute of Applied Sciences and Technology | Hassen I.,National Institute of Research and Physicochemical Analysis | And 3 more authors.
Chemistry and Biodiversity

Essential oils of Lavandula dentata, a Tunisian native plant, were isolated from leaves and flowers by hydrodistillation in a Clevenger-type apparatus and characterized by GC-FID and GC/MS analyses. The average essential oil yields, means of five replicates, were higher for the flowers (8.60 mg/g) than for the leaves (6.56 mg/g). A total of 72 compounds were identified, accounting for 98.1 and 97.7% of the total oil composition of the leaves and flowers, respectively. The main essential oil constituents were 1,8-cineole, camphor, and L-fenchone, accounting for 33.54, 18.89, and 8.36% in the leaf oils and for 19.85, 23.33, and 7.13% in the flower oils, respectively. Besides this quantitative variation, the results also showed considerable qualitative variation between the essential oils of the two plant parts analyzed. These differences might be adaptative responses to ecological exigencies. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich. Source

Limam I.,IRSTEA | Limam I.,University of Carthage | Limam I.,National Institute of Research and Physicochemical Analysis | Limam R.D.,IRSTEA | And 7 more authors.
Ecotoxicology and Environmental Safety

In this study isotopic tracing using 13C labelled pentachlorophenol (PCP) and 2,4,6-trichlorophenol (2,4,6-TCP) is proposed as a tool to distinguish the loss of PCP and 2,4,6-TCP due to biodegradation from other physical processes. This isotopic approach was applied to accurately assess in situ PCP and 2,4,6-TCP degradation under methanogenic conditions in several microcosms made up of household waste. These microcosms were incubated in anaerobic conditions at 35 °C (mesophilic) and 55 °C (thermophilic) without agitation. The volume of biogas produced (CH4 and CO2), was followed for a period of 130 days. At this stage of stable methanogenesis, 13C6-PCP and 13C6-2,4,6-TCP were introduced anaerobically in microcosms and its monitoring at mesophilic and thermophilic conditions was performed in parallel by gas chromatography mass spectrometry (GC-MS) and gas chromatography isotope-ratio mass spectrometry (GC-IRMS). This study proved the almost total dechlorination of bioavailable PCP and 2,4,6-TCP into 4-CP at 35 °C. Nevertheless, high rate adsorption in particular materials of the two compounds was observed. Furthermore, Carbon-13 Nuclear Magnetic Resonance (13C-NMR) Spectroscopy analysis of 13C labelled 2,4,6-TCP mesophilic incubations showed the partial mineralization of 4-CP at 35 °C to acetate and then to HCO3-. Consequently, NMR results confirm the biogas isotopic results indicating the mineralization of 13C labelled 2,4,6-TCP into 13C (CH4 and CO2). Concerning 13C labelled PCP mesophilic incubations, the isotopic composition of the biogas still natural until the day 262. In contrast, no dechlorination was observed at 55 °C. Thus PCP and 2,4,6-TCP were persistent in thermophilic conditions. © 2016 Elsevier Inc. Source

Alfeeli B.,Kuwait Institute for Scientific Research | Al-Rawashdeh M.,TU Eindhoven | Bumajdad A.,Kuwait University | Lawati H.A.,Sultan Qaboos University | And 4 more authors.
Nanotechnology Reviews

A growing number of initiatives on nanotechnology research, education, and industry have been recently launched by several Arab countries to quickly build scientific capacity and track worldwide developments in nanotechnology. Some countries, namely, the oil-rich countries, have allocated large funds to support these initiatives, which are intended to serve the national interests in energy, water and food supply, medicine, and local industry. The other Arab countries are also pursuing nanotechnology, however, with fewer funds but with more human resources. This study assesses the current status of nanotechnology in the Arab Republic of Egypt, Hashemite Kingdom of Jordan, Kingdom of Morocco, Kingdom of Saudi Arabia, Republic of Tunisia, State of Kuwait, State of Qatar, Sultanate of Oman, and the United Arab Emirates (UAE). The study is aimed at having a top-level overview of the status of existing, underdevelopment, and planed educational and research programs relevant to nanotechnology. The overview also includes nanotechnology research focus areas, challenges, and opportunities. Source

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