Water Researches and Technologies Center
Water Researches and Technologies Center
Taoufik G.,Water Researches and Technologies Center |
Taoufik G.,University of Carthage |
Khouni I.,Water Researches and Technologies Center |
Ghrabi A.,Water Researches and Technologies Center
Arabian Journal of Geosciences | Year: 2017
Located in the northeastern part of Tunisia, Wadi El Bey drains the watershed through farmland, industrial, and urban areas of the region. It serves to discharge treated wastewater of different types. In this work, the variations of the water quality of Wadi El Bey were studied and evaluated, during 2 years (2012–2013), using multivariate statistical techniques such as principal component analysis (PCA) and cluster analysis (CA). In addition, the similarities or dissimilarities among the sampling points were as well analyzed to identify spatial and temporal variations. The results obtained based on the cluster analysis, led to identify three similar water quality zones: relatively polluted (LP), moderately polluted (MP), and highly polluted (HP). The inorganic and organic parameters, temperature, conductivity, dissolved oxygen, chemical oxygen demand, salmonella, and enterococcus, seemed to be the most significant parameters of water quality. Three factors were identified as responsible for the data structure, explaining 60.95% of the total variance. The first factor is the physical and non-organic chemical parameters explaining 23.48% of the total variance. The second and third factors are, respectively, the microbiological (21.26%) and organic-nutrient (16.2%).This study shows that multivariate statistical methods can help the water managers to understand the factors affecting the water quality. © 2017, Saudi Society for Geosciences.
Kallel A.,University of Sfax |
Attour A.,Water Researches and Technologies Center |
Attour A.,University of Carthage |
Trabelsi I.,Water Research and Technologies Center
Arabian Journal of Geosciences | Year: 2017
Landfilling is a common practice worldwide for solid waste management. The leachate generated at landfill sites contains various organic and inorganic pollutants while it should be treated properly. In this study, the electrocoagulation (EC) process was recognized for its simplicity and effectiveness which was used for the treatment of leachate from the Djebel Chakir landfill site in northern Tunisia. In addition, we investigated the effect of microorganisms (e.g., bacteria, fungi, spore) on sludge production by the application of autoclaving treatment on raw leachate. The application of low current density (15 mA/cm2) within 2 h of treatment and using Al-Al electrodes revealed significant improvement of performance when autoclaving was applied. The chemical oxygen demand (COD) and nitrogen removal increased from 39 to 64% and from 13 to 30%, respectively. The sludge volume was reduced from 40 to 10%, and thus, its handling and disposal costs would be significantly decreased. The energy consumption rate was stable after 40 min of treatment at about 0.8 kWh/kg COD removed. Our study shows that removal of microorganisms by autoclaving prior to the EC process is promising for landfill leachate treatment. However, since autoclaving is far from being practical and cost-effective at full-scale plant, research on coupling EC with an alternative disinfecting process might be of great interest. © 2017, Saudi Society for Geosciences.
Touati K.,Water Researches and Technologies Center |
Touati K.,University of Valladolid |
Tadeo F.,University of Valladolid |
Elfil H.,Water Researches and Technologies Center
Energy | Year: 2017
The integration of Pressure Retarded Osmosis (PRO) with Seawater Reverse Osmosis is studied here in terms of energy recovery and changes of effluents. For this, two alternative integration designs are evaluated: one-stage PRO and a proposed two-stage PRO. For both designs the analysis is carried out without using external impaired water flows. The results show better performance of the proposed two-stage PRO. The study of operating conditions revealed that the increase of the feed concentration and the feed flow improves the performance of PRO. Lastly, for the proposed designs, the increase of the second stage recovery worsens the energy balance. © 2017 Elsevier Ltd
Eddine L.S.,University Mohamed Khider of Biskra |
Eddine L.S.,El - Oued University Center |
Segni L.,University of Ouargla |
Noureddine G.,Larbi Ben Mhidi University |
And 2 more authors.
International Journal of Pharmacognosy and Phytochemical Research | Year: 2014
In this study we investigate the antioxidant, anti-inflammatory, and antidiabetic activities of ethanolic leaves extracts of three selected varieties of Phoenix dactylifera L. namely: "Ghars", "Deglet Nour" and "Hamraya". The assessment of the antioxidant potential of crude leaves extracts, using superoxide anions inhibition, DPPH and total antioxidant activity essays, was carried out. Furthermore, the anti-inflammatory properties of the extracts were determined by measuring the inhibition of nitric oxide (NO) production. Moreover, the antidiabetic effect was evaluated by inhibition of α-amylase and α-glucosidase enzymes. The total phenolic content measured by Folin-ciocalteu method was as well conducted. The raw leaves extracts of the selected varieties was found to contain a high content of total phenolic content (342.45 mg GAE/ gDW for GE) and therefore exhibited a higher antioxidant activity and inhibitory effect of radicals scavenging activity against DPPH and superoxide anion (IC50=7.44 μg/mL and 39.11 μg/mL respectively). The three varieties exhibited significant anti-inflammatory effects using in-vitro inhibition of NO (IC50=240.28 μg/mL for GE). The extracts also displayed high inhibition actions against α-amylase. The results suggest that the leaves of the three selected varieties of Phoenix dactylifera L can be considered as a good source of natural antioxidant and anti-inflammation drugs as well as potent antidiabetic medicine.
Chulli B.,Water Researches and Technologies Center |
Davraz A.,Suleyman Demirel University of Turkey |
Makni J.,University of Sfax |
Bedir M.,Water Researches and Technologies Center |
Dhia H.B.,University of Sfax
Environmental Earth Sciences | Year: 2012
The Sfax Basin in eastern Tunisia is bounded to the east by the Mediterranean Sea. Thermal waters of the Sfax area have measured temperatures of 23-36°C, and electrical conductivities of 3,200 and 14,980 μS/cm. Most of the thermal waters are characterized as Na-Cl type although there are a few Na-SO 4-Cl waters. They issue from Miocene units which are made up sands and sandstones interbedded with clay. The Quaternary sediments cap the system. The heat source is high geothermal gradient which are determined downhole temperature measurements caused by graben tectonics of the area. The results of mineral equilibrium modeling indicate that the thermal waters of the Sfax Basin are undersaturated with respect to gypsum, anhydrite and fluorite, oversaturated with respect to kaolinite, dolomite, calcite, microcline, quartz, chalcedony, and muscovite. Assessments from various chemical geothermometers, Na-K-Mg ternary and mineral equilibrium diagrams suggest that the reservoir temperature of the Sfax area can reach up to 120°C. According to δ 18O and δ 2H values, all thermal and cold groundwater is of meteoric origin. © 2011 Springer-Verlag.
Belila A.,Water Researches and Technologies Center |
Fazaa I.,Water Researches and Technologies Center |
Hassen A.,Water Researches and Technologies Center |
Ghrabi A.,Water Researches and Technologies Center
International Journal of Environmental Science and Technology | Year: 2013
The molecular diversity of the purple photosynthetic bacteria was assessed during temporal pigmentation changes in four interconnected wastewater stabilization ponds treating domestic wastewater by denaturant gel gradient electrophoresis method applying pufM gene. Results revealed high phylogenetic diversity of the purple phototrophic anoxygenic bacteria community characterized by the presence of the purple non-sulfur, purple sulfur, and purple aerobic photosynthetic anoxygenic bacteria. This phototrophic bacterial assemblage was dominated by the purple non-sulfur bacteria group (59.3 %) with six different genera followed by the purple sulfur community (27.8 %) with four genera and finally 12.9 % of the pufM gene sequences were assigned throughout the aerobic anoxygenic phototrophic bacterial group. The purple phototrophic bacterial community was characterized by the presence of salt-dependant bacterial species belonging to the genus Marichromatium, Thiorhodococcus, Erythrobacter, and Roseobacter. The wastewater treatment plant performances were unsatisfactory, and the biological and chemical parameters suggested that the purple photosynthetic bloom was correlated with the eutrophic state. © 2013 Islamic Azad University (IAU).
Masrouhi A.,Water Researches and Technologies Center |
Masrouhi A.,Aix - Marseille University |
Bellier O.,Aix - Marseille University |
Ben Youssef M.,Water Researches and Technologies Center |
Koyi H.,Uppsala University
Journal of African Earth Sciences | Year: 2014
We used structural, stratigraphic and sedimentologic data, together with a comparison of nearby structures and a Bouguer gravity map, to evaluate the evolution of the Bled Dogra salt structure (northern Tunisia) during the Cretaceous. Triassic salt sheets are recognized in the northwestern region of the Tunisian Atlas. These salt sheets are the result of Cretaceous thick and/or thin-skinned extension along the south Tethyan margin. The Bled Dogra salt structure is one of these submarine allochthonous salt sheets, which was emplaced during the Early Cretaceous. The geologic framework, during this period, produces conditions for a predominantly gravity-driven deformation: extension has produced space for the salt to rise; vigorous differential sedimentation created differential loading that resulted in the emplacement and extrusion of a large volume of Triassic salt and formation of large submarine salt sheets. Geologic field data suggest an interlayered Triassic salt sheet within Albian sequences. Salt was extruded at the sea floor during the Early-Middle Albian and was initially buried by Middle-Late Albian strata. The Coniacian corresponds to a second transgressive cover onto the salt sheet after the gliding of the first salt cover (Late Albian-Turonian). In addition, this northwest Tunisian area exposes evidences for salt flow and abundant slump features at the base of a northward facing submarine slope, which was probably dominant from the Early Cretaceous to Santonian. Two gravity deformation processes are recognized: gravity gliding and gravity spreading. Acting concurrently, these two processes appear indistinguishable in this geologic context. Like the present-day salt-involved passive margins - such as the northern Gulf of Mexico, the Atlantic margin of Morocco, the Brazilian Santos basin, the Angola margin, Cadiz in western Iberia, and the Red Sea - the North African Cretaceous passive margin in Tunisia provides evidences that deformation in a passive-margin salt basin is predominantly gravity-driven deformation. © 2014 Elsevier Ltd.
Fourti O.,Water Researches and Technologies Center |
Jedidi N.,Water Researches and Technologies Center |
Hassen A.,Water Researches and Technologies Center
American Journal of Environmental Sciences | Year: 2011
Problem statement: The aim of this study was mainly focused on the evolution of microbial biomasses C and N during the composting of municipal solid wastes. Approach: The carbon and the nitrogen of the microbial biomass (B C and B N) were studied using the fumigation-extraction method. Results: The dynamics of the B C/B N ratio, index of the chemical composition of the whole microbial population suggested a shift in the composition of microbial populations during the process from prevailing bacteria and actinomycetes to prevailing fungi. Conclusion/Recommendations: Microbial characterization of composting is of importance for the optimization of the process and the quality of the end product. © 2010 Science Publications.
Akrout H.,Water Researches and Technologies Center |
Bousselmi L.,Water Researches and Technologies Center
Arabian Journal of Geosciences | Year: 2013
The electrochemical oxidation of synthetic wastewater which contains biazo dye [amido black (AB)] on boron-doped diamond anode, "BDD anode," was experimentally investigated to determine the influence of several operative parameters on the performance of the process. The study focalized on the effect of studied parameters on discoloration process and the degradation of the aromatic part of the dye molecule. Two distinct pathways with two different kinetics were observed. The decrease of pH improves the discoloration rate and the degradation of aromatic by-products after 90 min of electrolysis. The increase of current density has a considerable effect on discoloration and a little less effect on the aromatic derivative degradation. Hypochlorite electrogenerated from chloride addition exceptionally accelerates the discoloration, but it does not degrade aromatic derivatives as efficiently. It was observed that nitrates addition generates under electrolysis other derivates of AB as different colors than the dye one. The current efficiency depends very little on the initial pH; however, higher energy consumptions are obtained. © 2012 Saudi Society for Geosciences.
PubMed | National Agronomic Institute of Tunisia, Water Researches and Technologies Center and University of Naples Federico II
Type: | Journal: Chemosphere | Year: 2016
Pentachlorophenol (PCP) is a toxic compound which is widely used as a wood preservative product and general biocide. It is persistent in the environment and has been classified as a persistent organic pollutant to be reclaimed in many countries. Fungal bioremediation is an emerging approach to rehabilitating areas fouled by recalcitrant xenobiotics. In the present study, we isolated two fungal strains from an artificially PCP-contaminated soil during a long-term bioremediation study and evaluated their potential as bioremediation agents in depletion and detoxification of PCP in soil microcosms. The two fungal strains were identified as: Byssochlamys nivea (Westling, 1909) and Scopulariopsis brumptii (Salvanet-Duval, 1935). PCP removal and toxicity were examined during 28 days of incubation. Bioaugmented microcosms revealed a 60% and 62% PCP removal by B.nivea and S.brumptii, respectively. Co-inoculation of B.nivea and S.brumptii showed a synergetic effect on PCP removal resulting in 95% and 80% PCP decrease when initial concentrations were 12.5 and 25mgkg