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1.
Maroua El Ouaer Amjad Kallel Mariam Kasmi Abdennaceur Hassen Ismail Trabelsi 《Arabian Journal of Geosciences》2017,10(20):457
The potential of the autoclaved Tunisian landfill leachate treatment using microalgae (Chlorella sp.) cultivation was investigated in this study. Landfill leachate was collected from Borj Chakir landfill, Tunisia. A full factorial experimental design 22 was proposed to study the effects of the incubation time and leachate ratio factors on the organic matter removal expressed in chemical oxygen demand (COD) and ammoniacal nitrogen (NH4─N) and on the biological response of Chlorella sp. expressed by the cell density and chlorophyll content. All experiments were batch runs at ambient temperature (25 ± 2 °C). The Chlorella sp. biomass and chlorophyll a concentrations of 1.2 and 5.32 mg L?1, respectively, were obtained with 10% leachate spike ratio. The obtained results showed that up to 90% of the ammoniacal nitrogen in landfill leachate was removed in 10% leachate ratio spiked medium with a residual concentration of 40 mg L?1. The maximum COD removal rate reached 60% within 13 days of incubation time indicating that microalgae consortium was quite effective for treating landfill leachate organic contaminants. Furthermore, with the 10% leachate ratio spiked medium, the maximum lipid productivity was 4.74 mg L?1 d?1. The present study provides valuable information for potential adaptation of microalgae culture and its contribution for the treatment of Tunisian landfill leachate. 相似文献
2.
Imene Rouis-Zargouni Jean-Louis Turon Laurent Londeix Néjib Kallel Latifa Essallami 《Comptes Rendus Geoscience》2012,344(2):99-109
Using the analysis of dinoflagellate cysts in three deep-sea sediments cores situated in the Sicilian-Tunisian Strait, in the Gulf of Lions and in the Alboran Sea, we reconstruct the paleoenvironmental changes that took place during the last glacial-interglacial transition in the western Mediterranean Sea. The development of the warm microflora Impagidinium aculeatum and especially Spiniferites mirabilis appears to be an important proxy for recognizing warm periods as the Bölling/Alleröd and the Early Holocene. Bitectatodinium tepikiense, Spiniferites elongatus and Nematosphaeropsis labyrinthus mark the end of the Heinrich event 1 and the Younger Dryas. This cold microfloral association confirms the drastic climate changes in the western Mediterranean Sea synchronous to the dry and cold climate which occurred in the South European margin. The dinocyst N. labyrinthus shows high percentages in all studied regions during the Younger Dryas. Its distribution reveals a significant increase from the South to the North of this basin during this cold brief event. Thus, we note that this species can be considered as a new eco-stratigraphical tracer of the Younger Dryas in the western Mediterranean Sea. 相似文献
3.
The coastal area off the city of Sfax (730,000 inhabitants), well-known for fisheries and industrial activities, receives high inputs of organic matter mostly anthropogenic. Eighteen stations were selected in the vicinity of the direct discharge of industrial sewage effluents in the sea in order to study the spatial distribution of the organic contamination. Surface sediments sampled in the shallow shelf were analysed for hydrocarbons by Fourier transform infrared spectroscopy, gas chromatography and gas chromatography/mass spectrometry. Total hydrocarbon distributions revealed high contamination as compared to other coastal Mediterranean sites, with an average concentration of 1865 ppm/dry weight sediment. Gas chromatographic distribution patterns, values of unresolved mixture/n-alkane ratio and distributions of steranes and hopanes confirmed a petroleum contamination of the Arabian light crude oil type. Biogenic compounds were also identified with a series of short-chain carbon-numbered n-alkenes in the carbon range 16-24. 相似文献
4.
5.
Evaluation of hydrocarbon pollution in marine sediments of Sfax coastal areas from the Gabes Gulf of Tunisia,Mediterranean Sea 总被引：1，自引：0，他引：1
Hatem Zaghden Monem Kallel Boubaker Elleuch Jean Oudot Alain Saliot Sami Sayadi 《Environmental Earth Sciences》2014,72(4):1073-1082
The Tunisian environmental legislation that follows the EC Directives requires monitoring of persistent, toxic and bio-accumulated substances commonly considered as hazardous substances. In order to comply with this requirement, samples of sea water, sediment and biota from the urbanized and industrialized coast line of Sfax city are investigated. This study presents the results of petroleum hydrocarbon content, distribution and probable origin (anthropogenic and/or biogenic) in 16 intertidal sediments of Sfax coastal area. Alkane distribution indices and hydrocarbon distribution patterns are used to identify natural and anthropogenic input. Non-aromatic hydrocarbons present a high concentration with a range varying from 180 to 1,400 μg/g of dry sediment. The total concentrations of polycyclic aromatic hydrocarbons (PAHs) varied from 0.41 to 5.6 μg/g dry weight. These concentrations are comparable to other marine areas that receive important inputs. n-Alkanes with carbon number ranging from 15 to 35 are identified to be derived from both biogenic and anthropogenic sources in varying proportions. Pristane/phytane ratio shows values lower than 1.4 suggesting the presence of petroleum contamination. This is confirmed by the presence of a large group of unresolved complex mixture and the identification of hopanes with predominant C29 and C30 compounds and steranes with predominance of C27 over C28 and C29 compounds. Ratios of selected PAH concentrations indicate petrogenic and pyrolytic origin of hydrocarbons. Anthropogenic hydrocarbon inputs were more apparent at sites associated with industrial discharges, shipping activities and sewage outfalls. 相似文献
6.
Fatma Aloulou Monem Kallel Mohamed Dammak Boubaker Elleuch Alain Saliot 《Environmental Earth Sciences》2010,61(1):1-10
We investigated the mineral composition and trace element contents of dustfall with different deposited phases at the Minqin
Oasis, in China’s Hexi Corridor. The contents of elements such as Pb, Cd, Cu, As, Sb, Se, Rb, Cs, and Ba (believed to be of
anthropogenic origin) indicated that the significance of human impacts on dust emissions increased from 1970s to the early
2000s. However, variations in the content of elements including Sc, Mn, Na, Cr, V, Eu, Ce, Nb, Zr, La, and Ce (believed to
originate from natural processes such as physical and chemical weathering) show no obvious changes in the major potential
dust source areas (PSAs) in this region. In addition, analysis of the assemblage of trace elements in dustfall indicated that
the elements assumed to originate from anthropogenic and natural processes appear to be intertwined, leading to difficulties
and uncertainties in identifying the PSAs and evaluating the significance of human impacts on dust emissions. Comparisons
of the element contents of dustfall collected in Beijing and Minqin with similar data for Beijing show that under different
conditions some differences in ranges are permitted; the contents of most trace elements were similar even though the dustfall
in the two areas came from different sources. These results suggest that before attempting to identify major PSAs, researchers
should perform an integrated analysis that includes the mineral, elemental, geomorphological, vegetation cover, climatic conditions,
and other characteristics of the regions being studied. 相似文献
7.
Rakia S’habou Moncef Zairi Amjed Kallel Abdelwaheb Aydi Hamed Ben Dhia 《Environmental Geology》2009,58(3):679-686
Olive oil is a typical and valuable agro-industrial product in Mediterranean countries. In Tunisia, olive mill wastewaters
(OMW) reach an amount of about 1,000,000 t year−1 and constitute a serious organic pollution risk because of the high chemical oxygen demand values and the presence of phytotoxic
and antibacterial polyphenols. OMW have been generally stored in pond sites to be eliminated by natural evaporation or valorised
by spreading on cultivated soils or by composting. Many researches on the interactions of OMW with soils at laboratory scale
(columns) have been reported, but less attention have been paid to the effect of OMW on soils at field scale. The aim of this
work is to investigate an area used for >15 years as an uncontrolled OMW pond site. The transformations of soil properties
and groundwater occurring during OMW storage were characterised by the pH, phenolic contents, electrical conductivity (EC),
moisture content and organic contents. The soil samples were taken from two borings and compared to those of a control one
located near the pond site. Groundwater samples were taken on the accessible and nearest water wells to the evaporation ponds.
The permeable silty and sandy layers in the site support the infiltration of OMW near the evaporation ponds. This infiltration
has reached a depth of 6 m at a distance of almost 50 m laterally. The results show that the OMW infiltration in the subsoil
has affected the pH, EC, organic content, phenolic compounds and the moisture. 相似文献
8.
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. 相似文献
9.
The treatment of landfill leachate by reverse osmosis (RO) generates huge volumes of heavily polluted concentrate that has to be properly treated before its discharge into the environment. The aim of this work was to assess the solidification/stabilization (S/S) treatment of the leachate concentrate (LC) for chemical/physical immobilization of contaminants and for obtaining durable monolithic matrix suitable for storage, landfilling, or use. In addition, the possible use of brick waste as a partial replacement of natural aggregates used for S/S process was investigated. Concrete mixtures were prepared using local PC, sand, gravel, and tap water/LC. The substitution of coarse aggregate material by brick waste was examined for the replacement ratios 25, 50, and 75%. Hardened concrete specimens were subject to compressive test as well as flexural strength test at 7 and 28 days. Besides, a leaching test was performed, and the collected eluates were analyzed for pH, total dissolved solids, chemical oxygen demand, chlorides, sulfates, phosphorus, and heavy metals. The aggregate replacement with brick waste showed various trends according to the substituted fraction size and ratio. A 28-day compressive strength of more than 25 MPa was obtained even at 50% simultaneous substitution of PC, gravel, and sand. Leaching test analysis confirmed that S/S could be a successful treatment for RO LC decreasing most of the pollutants to comply with landfilling criteria, except for chromium known to be mobile at high pH. Furthermore, the substitution of natural aggregates with brick waste revealed the possibility to cast valuable masonry units. However, a long-term assessment is still needed to ensure the mechanical and chemical stability/durability of concrete. 相似文献
10.
Hydrocarbons in surface sediments from the Sfax coastal zone, (Tunisia) Mediterranean Sea 总被引：1，自引：0，他引：1
Zaghden H Kallel M Louati A Elleuch B Oudot J Saliot A 《Marine pollution bulletin》2005,50(11):1287-1294
The Semi-enclosed Mediterranean Sea records various signals of high anthropic pressures from surrounding countries and the industrialized European countries. This is particularly true for oil pollution. Although accounting for 1% of the world's ocean surface, it receives about 25% of the petroleum inputs to the ocean. To achieve a global budget we need to collect information from different parts of the Mediterranean. Particularly, we focus in this paper on the Southern Mediterranean, where data are presently very scarce. In this context, the University of Sfax has undertaken an estimation of hydrocarbon pollution along the coasts of Sfax and Gabès Gulf. Non-aromatic hydrocarbons were analysed in 8 surface sediments by FT/IR and GC/MS. Non-aromatic hydrocarbon concentrations vary in the range 310-1406 microg g(-1) sediments dry weight, which is high, compared to other Mediterranean sites. GC/MS data indicate a large group of unresolved compounds suggesting a petroleum contamination, confirmed by the identification of hopanes with predominant C29 and C30alpha,beta compounds and steranes with predominance of C27 over C28) and C29 compounds. 相似文献