Water Research and Technology Center

Soliman, Tunisia

Water Research and Technology Center

Soliman, Tunisia

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Lachaal F.,Water Research and Technology Center | Lachaal F.,National Agronomic Institute of Tunisia | Bedir M.,Water Research and Technology Center | Tarhouni J.,National Agronomic Institute of Tunisia | Leduc C.,IRD Montpellier
IAHS-AISH Publication | Year: 2010

Like all other Mediterranean countries, Tunisia provides multiple examples of groundwater degradation due to its overexploitation. This is especially the case in the Zéramdine-Mahdia-Jébéniana region (central east Tunisia), where recent measurements revealed an important piezometric drop in the Miocene aquifers. Through hydrodynamic and hydrochemical analysis, we studied the influence of the head decrease on groundwater flow and quality. The spatial and temporal analysis of the piezometry identified two totally independent compartments. This was confirmed by the hydrogeochemical and multivariate statistical analysis. The Miocene aquifer system was divided into two water groups: (1) the Zéramdine-Béni Hassen aquifer which is characterized by freshwater, Na-Ca-Cl-SO4 facies, and salinity increase from west to east that is coinciding with the principal water flow direction; and (2) the Mahdia-Ksour Essef aquifer, which is defined throughout by high and heterogeneous salinity and Na-Cl facies. Copyright © 2010 IAHS Press.


Benzarti S.,Okayama University of Science | Hamdi H.,Water Research and Technology Center | Mohri S.,Okayama University of Science | Ono Y.,Okayama University of Science
International Journal of Phytoremediation | Year: 2010

A hydroponics experiment using hyperaccumulator Thlaspi caerulescens (alpine pennycress) and non-specific accumulator Raphanus sativus (common radish) was conducted to investigate the short-term effect of increasing Cd concentrations (0, 25, 50, 75, 100 μM) on metal uptake, chlorophyll content, antioxidative enzymes, and apoplastic bypass flow. As expected, T. caerulescens generally showed better resistance to metal stress, which was reflected by higher Cd accumulation within plant tissues with no signs of chlorosis, or wilt. Glutathione reductase (GR) and superoxide dismutase (SOD) activities in fresh leaves were monitored as the plant metal-detoxifying response. In general, both plant species exhibited an increase trend of GR activity before declining at 100 μM likely due to excessive levels of phytotoxic Cd. SOD activity exhibited almost a similar variation pattern to GR and decreased also at 100 μM Cd. For both plant species, fluorescent PTS uptake (8-hydroxyl, 3,6-pyrenetrisulphonic acid) increased significantly with metal level in exposure solutions indicating that Cd has a comparable effect to drought or salinity in terms of the gain of relative importance in apoplastic bypass transport under such stress conditions. © Taylor & Francis Group.


Lachaal F.,Water Research and Technology Center | Lachaal F.,National Agronomic Institute of Tunisia | Bedir M.,Water Research and Technology Center | Tarhouni J.,National Agronomic Institute of Tunisia | And 2 more authors.
Journal of African Earth Sciences | Year: 2011

The Zéramdine and Mahdia-Jébéniana blocks are located in the Sahel region in east-central Tunisia. Active tectonics have divided the region into numerous sub-units, as result of multiple phases of distension and compression. The Miocene fluvio-deltaic sediment sandy layers have aquiferous capacities but their hydraulic properties are still unknown, due to the lack of investigation wells. This study proposes a new description of the regional hydrogeology of Miocene deposits. Seismic-reflection and wireline logging of petroleum and water wells were used to understand the structure and the geometry of the Miocene reservoirs. The groundwater flow and its relationship to the sedimentary and tectonic context were then identified by studying piezometry and hydrochemistry.Two Miocene deep aquifer systems were identified: (1) Zéramdine-Béni Hassen to the north and (2) Jébéniana-Ksour Essef to the south. These aquifers are separated by the Mahdia graben. Other major tectonic structures, such as the Zéramdine fault corridor, the Moknine graben, and the El-Jem half-graben represent lateral boundaries for these aquifers. Other deeper sandy and clayey-sandy reservoirs were also identified in the area. Their repartition, thickness and depth vary from one block to other.Hydrodynamics of the deep aquifers seems to be controlled by geological structures. Two independent compartments were identified: in the northern block groundwater flows from West to East and from Northwest to Southeast, while in the southern block it flows from Northwest to Southeast. Geochemical facies are of two types: Na-Ca-Cl-SO4 for the Zéramdine-Béni Hassen deep aquifer and Na-Cl for the Jébéniana-Ksour Essef deep aquifer. The hydrodynamic and geochemical results confirm the sharing of the Miocene sediments into two aquifers. © 2011 Elsevier Ltd.


Ayari F.,Water Research and Technology Center | Hamdi H.,Water Research and Technology Center | Jedidi N.,Water Research and Technology Center | Gharbi N.,University of Tunis | Kossai R.,University of Tunis
International Journal of Environmental Science and Technology | Year: 2010

A field study was carried out to evaluate long-term heavy metal accumulation in the top 20 cm of a Tunisian clayey loam soil amended for four consecutive years with municipal solid waste compost at three levels (0, 40 and 80 t/ha/y). Heavy metals uptake and translocation within wheat plants grown on these soils were also investigated. Compared to untreated soils, compost-amended soils showed significant increases in the content of all measured metals: cadmium, chromium, copper, nickel, lead and zinc in the last three years, especially for plots amended with municipal solid waste compost at 80 t/ha/y. Wheat plants grown on compost-amended soils showed a general increase in metal uptake and translocation, especially for chromium and nickel. This heavy metal uptake was about three folds greater in plots amended at 80 t/ha/y as compared to plots amended at 40 t/ha/y. At the end of the experimental period, the diluting effect resulting from enhanced growth rates of wheat plants due to successive compost applications resulted in lower concentrations in the plants (grain part) grown on treated plots. On the other hand, chromium and nickel were less mobile in the aerial part of wheat plants and were accumulated essentially in root tissues. Plant/soil transfer coefficients for compost-amended treatments were higher than threshold range reported in the literature, indicating that there was an important load/transfer of metal ions from soils to wheat plants. © IRSEN, CEERS, IAU.


Lachaal F.,Water Research and Technology Center | Lachaal F.,National Agronomic Institute of Tunisia | Mlayah A.,Water Research and Technology Center | Bedir M.,Water Research and Technology Center | And 2 more authors.
Computers and Geosciences | Year: 2012

In this work, an integrated methodology was developed to investigate hydrological processes in Zéramdine-Béni Hassen Miocene aquifer and to validate the groundwater proprieties deduced from the geological, geophysical, hydrodynamic and hydrochemical studies done in the region, using the coupling of groundwater flow model MODFLOW 2000 code with Geographic Information System tools. A 3-D groundwater flow model was developed for this aquifer using a large amount of available geological and hydrological data.The groundwater flow model was calibrated and validated with datasets during the 1980-2007 period. The results show that the ZBH aquifer exhibits the highest sensibility to changes of water infiltration and hydraulic conductivity. The model simulation shows a good degree of understand to the aquifer hydrogeology. The model can be regarded as a useful tool for analyzing the hydrological processes for complex groundwater that have similar geological and hydrogeological conditions and will help to propose a management rescue plan for the studied aquifer, especially for aquifer characterization in arid and semi arid regions. © 2012 Elsevier Ltd.


PubMed | University of Tunis and Water Research and Technology Center
Type: | Journal: Environmental science and pollution research international | Year: 2016

The bacterial community structure and diversity were assessed at the scale of rotating biodisk procedure (RB) in a semi-industrial pilot plant. As well, the Salmonella community was particularly monitored, and the effects of ultraviolet (UV-C


Moumni Y.,Tunis el Manar University | Msaddek M.H.,Tunis el Manar University | Chermiti A.,Water Research and Technology Center | Chenini I.,Tunis el Manar University | And 2 more authors.
Journal of African Earth Sciences | Year: 2016

Fracture network properties in geological media are described and analyzed to evaluate the hydrodynamic functioning of fractured aquifer as well as permeability and transmissivity. In this paper, a concise approach for mapping and analyzing fracture properties in the outcrops was applied. The adopted methodology aims to explore the spatial distribution and properties of fractures to estimate the aquifer permeability. A detailed geological mapping was established to define the geometry and spatial extension of the fractured aquifer. A correlation between these data and the transmissivity values is discussed to evaluate groundwater flow in fractured aquifer. The Horchane basin was explored to investigate fracture distribution and their aperture, density and frequency. The fracture mapping at 1/1 scale was done over 42 stations containing 1000 fractures. Results of this investigation show that fracturing is the only parameter responsible for the circulation of water in the aquifer. Aperture and density of fractures have an important effect on permeability and water flow in the Horchane-Braga basin. © 2016 Elsevier Ltd


Khadhar S.,Water Research and Technology Center | Higashi T.,University of Tsukuba | Hamdi H.,Water Research and Technology Center | Matsuyama S.,University of Tsukuba | Charef A.,Water Research and Technology Center
Journal of Hazardous Materials | Year: 2010

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds which may be present as contaminants in wastewater sewage sludge. Due to their toxicity and persistence in the solid phase, information should be gathered relating to their presence in sewage sludge in order to determine their contamination risks after land application. In this study, sewage sludge samples from nine Tunisian wastewater treatment plants (WWTPs) were characterized for the total content in 16 EPA-priority PAHs using an optimized extraction protocol. These WWTPs differ in the type of applied treatment and the wastewater source. Through this first assessment of PAHs in Tunisian sludges, their total concentration varied from 96 to the highest level of 7718ngg-1. Regardless of the source of wastewater, the highest PAH content was found in sludges deriving from untreated wastewater (natural lagooning). In addition, some correlation was found between the distribution patterns of each PAH, the type of applied treatment on one hand and the wastewater source on other hand. © 2010 Elsevier B.V.


Brahmi M.,Water Research and Technology Center | Belhadi N.H.,Water Research and Technology Center | Hamdi H.,Water Research and Technology Center | Hassen A.,Water Research and Technology Center
Journal of Environmental Sciences | Year: 2010

This work aimed to study UV-resistant strains of Pseudomonas aeruginosa, to propose a formulation of the kinetics of secondary treated wastewater disinfection and to underline the influence of suspended solids on the inactivation kinetics of these strains. Some investigations were carried out for the validation of some simulation models, from the simplest, the kinetics model of Chick-Watson reduced to first order, to rather complex models such as multi-kinetic and Collins-Selleck models. Results revealed that the involved processes of UV irradiation were too complex to be approached by a simplified formulation, even in the case of specific strains of microorganisms and the use of nearly constant UV radiation intensity. In fact, the application of Chick-Watson model in its original form is not representative of the kinetics of UV disinfection. Modification, taking into account the speed change during the disinfection process, has not significantly improved results. On the other hand, the application of Collins-Selleck model demonstrates that it was necessary to exceed a least dose of critical radiation to start the process of inactivation. To better explain the process of inactivation, we have assumed that the action of disinfectant on the survival of lonely microorganisms is faster than its action on suspended solids protected or agglomerated to each others. We can assume in this case the existence of two inactivation kinetics during the processes (parallel and independent) of the first-order. For this reason, the application of a new kinetic model by introducing a third factor reflecting the influence of suspended solids in water on disinfection kinetics appeared to be determinant for modeling UV inactivation of P. aeruginosa in secondary treated wastewater. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.


PubMed | Water Research and Technology Center
Type: Journal Article | Journal: Current microbiology | Year: 2015

The goal of this work was the investigation of correlation between some peculiarities of membrane fatty acids composition, biofilm formation, and motility of dam and/or seqA mutants in Salmonella typhimurium bacterial cells and UV-C radiations. The exposure changed the fatty acids composition of dam and seqA/dam strains. Significant increase of unsaturated fatty acids was observed. Swarming and swimming were enhanced only in dam mutant and biofilm formation increased significantly in all tested strains after UV-C exposure. These results suggest that increased sensitivity toward UV-C rays in dam strains might be due to fatty acid alteration.

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