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Hachani F.,Water Researches and Technologies Center | Balti H.,University of Carthage | Kadri A.,University of Carthage | Gasmi M.,University of Carthage
Acta Geophysica | Year: 2016

Located between eastern segments of the Atlas and Tell-Rif orogenic belts, the "Dome zone" of northern Tunisia is characterized by the juxtaposition of various structures that mainly controlled the long geodynamic history of this part of the south-Tethyan Margin. To better understand the organization and deep extension of these structures, gravity data from the Teboursouk key area are proposed. These data include the plotting of Bouguer anomaly map and related parameters such as vertical and horizontal gradients, upward continuation and Euler solution. Compared to geological and structural maps available, they allow the identification of new deep structures and greater precision regarding the characteristics and organization of known ones; consequently, an updated structural pattern is proposed. © 2016 Hachani et al. Institute of Geophysics, Polish Academy of Sciences. Source

Hadhemi B.,University of Carthage | Fatma H.,Water Researches and Technologies Center | Ali K.,University of Carthage | Mohamed G.,University of Carthage
Journal of African Earth Sciences | Year: 2016

Gravity data was used to investigate sub-surface structure of the Teboursouk and El Krib plains belonging to the dome zone in the Northwest of Tunisia. Analysis of the gravity data included the computation of the Bouguer anomaly, the horizontal and vertical gravity gradients, the upward continuations, Euler deconvolution and analytic signal of high-resolution. The Bouguer anomaly map (d = 2.4 g cm-3) has provided information on the variation of the underground density and shown contrasting anomalous zones. The treatments applied to the Bouguer anomaly map have detected new deep faults and provided details on their dips and depths (exceeding 1500 m per places).Statistical analysis of the gravity data filtering shows that the study area is divided by four major faults with NW-SE, NE-SW, E-W and N-S trends. These faults have contributed to the structuring of the area.The results provide confirmation of some faults already recognized or inferred from the previous structural studies, and specify their depths and dips. While large number of new faults that remained undetected until now, have been highlighted. © 2016 Elsevier Ltd. Source

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. Source

Eturki S.,Water Researches and Technologies Center | Jedidi N.,Water Researches and Technologies Center | Ben Dhia H.,University of Sfax
Surface Engineering and Applied Electrochemistry | Year: 2012

This article investigates the potential of clay material (bentonite), having the following structure formula Ca 0.014Na 0.404K 0.16(Si 7.65Al 0.35)(Al 2.910Fe 0.762Mg 0.376)O 22, as an ion exchange medium for ammonium removal from effluent and watercourse. Batch experiments were carried out indicating that bentonite is highly selective for the ammonium ion. Experimental data show that 94% of ammonium was removed from aqueous solution in comparison with its initial concentration, with an overall ion exchange capacity of ≈50 meq/100 g medium: on average. Batch tests were performed under a range of conditions to assess the effect of contact time, solution pH, solution concentration and temperature on the performance and capacity of the media for this application. A detailed examination of the data shows that increasing solution concentration and increased contact time provide the best performance at an optimum pH between 6 and 8. Adsorption capacity varied from 34 to 48 meq/100 g with temperature increasing from 20 to 40°C, therefore ammonium removal was controlled essentially by an endothermic process based on chemisorption phenomena. The Langmuir and Freundlich models (isotherms) were applied to the data obtained from the batch studies. It seems that the second model fits well with the experimental data, since it exhibits more satisfactory correlation coefficient value (0.97 and 0.45, respectively). © 2012 Allerton Press, Inc. Source

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. Source

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