Potential Occurrence of MTBE and BTEX in Groundwater Resources of Amman–Zarqa Basin,Jordan     

Mustafa Al Kuisi  Ghazi Saffarini  Najal Yaseen  Mahmoud Alawi 《洁净——土壤、空气、水》2012,40(8):808-816

This study investigates potential occurrence, distribution, and sources of the newly added gasoline oxygenate, methyl‐tert‐butyl ether (MTBE) and the petroleum derivatives benzene, toluene, ethylbenzene, and xylenes called collectively, BTEX, in Jordan's heavily populated Amman–Zarqa Basin (AZB). It presents the first data on the levels of MTBE and BTEX in the aquifers of this basin. One hundred and seventy‐nine (179) groundwater wells were sampled near petrol service stations, oil refinery storage tanks, car wrecks, bus stations, and chemical industries at different locations in the basin. Headspace GC and purge and trap GC–MS were utilized to determine the target substances in the samples. Concentrations of BTEX varied between no‐detection (minimum) for all of them to 6.6 µg/L (maximum) for ethylbenzene. MTBE was found in few samples but none has exceeded the regulated levels; its concentrations ranged between no‐detection to 4.1 µg/L. However, though the contamination levels are very low they should be considered alarming.  相似文献   

Delineation of Near-Surface Structure in the Southern Part of 15th of May City, Cairo, Egypt Using Geological, Geophysical and Geotechnical Techniques     

Adel M. E. Mohamed  Sultan A. Sultan Araffa  Nagi I. Mahmoud 《Pure and Applied Geophysics》2012,169(9):1641-1654

The integration of geological, geophysical, and geotechnical interpretation at the southern part of 15th of May City, have been used to evaluate the subsurface stratigraphy, especially the clay layer which may cause serious danger to construction. Those techniques have been used to delineate the subsurface structures as normal faults, which play a critical role on the stability of buildings. Geological setting of the area has been evaluated through the construction of a geological map from different geological sections and samples obtained from more than 30 observation points. Geophysical tools such as vertical electrical soundings (12 VESs), 2-D dipole–dipole array (7 sections), P-wave shallow seismic refraction (31 profiles) and multiple channel analysis of surface waves (31 MASW profiles) have been carried out to image the subsurface situation. Geotechnical evaluation using 26 boreholes, samples, laboratory tests and geotechnical parameters has been done at the area of interest. The geological setting demonstrates that the city had been constructed on the second and third members of Qurn Formation (Upper Eocene) composed of argillaceous limestone, marl and shale. Two normal faults are passing through the area were observed. The resistivity (VES and dipole–dipole) and seismic (P-waves and MASW) results reflect the presence of the two normal faults cross the study area, affecting the obtained section of marl, clayey marl and limestone layers. The geotechnical information indicate the presence of the normal faults and the existence of clay layer with swelling ability reaching 140%, which may cause cracks in the upper layers and/or subsidence.  相似文献   

Probabilistic earthquake hazard analysis for Cairo,Egypt   总被引：1，自引：1，他引：0  

Ahmed Badawy  Ibrahim Korrat  Mahmoud El-Hadidy  Hanan Gaber 《Journal of Seismology》2016,20(2):449-461

Cairo is the capital of Egypt and the largest city in the Arab world and Africa, and the sixteenth largest metropolitan area in the world. It was founded in the tenth century (969 ad) and is 1046 years old. It has long been a center of the region’s political and cultural life. Therefore, the earthquake risk assessment for Cairo has a great importance. The present work aims to analysis the earthquake hazard of Cairo as a key input’s element for the risk assessment. The regional seismotectonics setting shows that Cairo could be affected by both far- and near-field seismic sources. The seismic hazard of Cairo has been estimated using the probabilistic seismic hazard approach. The logic tree frame work was used during the calculations. Epistemic uncertainties were considered into account by using alternative seismotectonics models and alternative ground motion prediction equations. Seismic hazard values have been estimated within a grid of 0.1°?×?0.1 ° spacing for all of Cairo’s districts at different spectral periods and four return periods (224, 615, 1230, and 4745 years). Moreover, the uniform hazard spectra have been calculated at the same return periods. The pattern of the contour maps show that the highest values of the peak ground acceleration is concentrated in the eastern zone’s districts (e.g., El Nozha) and the lowest values at the northern and western zone’s districts (e.g., El Sharabiya and El Khalifa).  相似文献   

Adsorption Behavior of Solvent‐Free Microwave Assisted Nanosilica‐Functionalized Carboxylic Acids for the Removal of Cobalt (II) from Water          下载免费PDF全文

Mohamed E. Mahmoud  Amr A. Yakout  Mahmoud I. A. Elserw  Maher M. Osman 《洁净——土壤、空气、水》2016,44(8):1011-1022

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Histopathologic biomarker response of clam, <Emphasis Type="Italic">Ruditapes decussates</Emphasis>, to organophosphorous pesticides reldan and roundup: A laboratory study     

Nahla S. El-Shenawy  Tarak I. S. Moawad  Mahmoud E. Mohallal  Ismail M. Abdel-Nabi  Inas A. Taha 《Ocean Science Journal》2009,44(1):27-34

Clam Ruditapes decussates was used as a biomonitoring organism to measure the potential impact of pollution. The present study investigated histological alterations of R. decussates following a long-term exposure to a sublethal-level of pesticides Reldan and Roundup. The clams were taken to the laboratory and kept for days to adjust to a continuous closed flow system with quality water control. After the adjustment period, clams were exposed either to sublethal concentrations of Reldan (0.6 μl L^?1) or Roundup (1.1 μl L^?1) for 90 days. Clams were taken to determine the histological damage at 30, 60 and 90 days. Most histological alterations were highly localized in the glandular cells of the gills, mantle tissues and digestive gland; secretions of glandular cells were found to be increased by increasing the time of exposure. Histopathological results showed the activation of resistance mechanisms that allowed the clams to survive under sublethal stresses. Thus, histological changes on localized tissues were sensitive and they have positive correlation to the time of exposure to the pesticides, suggesting that they may serve as biomarkers for Reldan and Roundup exposures.  相似文献   

Interpretation of Magnetic Data Through Particle Swarm Optimization: Mineral Exploration Cases Studies     

Essa  Khalid S.  Elhussein  Mahmoud 《Natural Resources Research》2020,29(1):521-537

Natural Resources Research - This paper emphasizes the use of the particle swarm optimization to infer second moving average residual magnetic anomalies. This approach was used to remove the impact...  相似文献   

Thermal microstructural changes of grain-supported limestones     

Abdel Monem Mohamed Soltan  Wolf A. Kahl  Mahmoud M. Hazem  Mechael Wendschuh  Reinhard X. Fischer 《Mineralogy and Petrology》2011,103(1-4):9-17

The microstructure of grainstone, grain-supported limestone, samples representing different geographic and stratigraphic intervals in Egypt were examined before and after calcination at 950°C for 0.25, 0.5, 1 and 2?h. The examination utilized are X-ray diffraction (XRD), X-ray fluorescence (XRF), transmitted light microscopy (TLM), scanning electron microscopy (SEM) and X-ray micro tomography (??-CT). Both the free lime content and reactivity of the produced quicklime were measured. The quicklime produced at 950°C for 0.25 and 0.5?h is un-reactive (R_DIN < 10) due to its low content of free lime. However, quicklime produced at 1 and 2?h conditions is highly reactive (R_DIN > 30) with variable reactivity due to the differences in the lime microfabric. The grainstones enriched in nummulites resulted in quicklime of higher reactivity than those dominated by foraminifera, peloids and miliolids. This is mainly attributed to the preservation of the intraparticle pores of the original limestone and the development of pinhole and fracture micropores. The shape of pores and not their amount is the main controlling variable in the quicklime reactivity. The grainstones enriched in fracture pores showed more reactive lime, whereas those with compact structures are less reactive post calcination.  相似文献   

Palynostratigraphy and paleoenvironmental significance of the Cretaceous succession in the Gebel Rissu-1 well,north Western Desert,Egypt     

Salah El Beialy  Maher El-Soughier  Sayed Abdel Mohsen  Haytham El Atfy 《Journal of African Earth Sciences》2011,59(2-3):215-226

Palynological investigation of the Cretaceous Abu Roash, Bahariya, Kharita, Alamein, Alam El Bueib and Betty formations, encountered in the Gebel Rissu-1 well, north Western Desert, Egypt yielded 27 species of pteridophytic spores, 24 of gymnosperm pollen, 25 of angiosperm pollen and 11 of dinoflagellate cysts in addition to some acritarchs, foraminiferal test linings and freshwater algae. This enabled us to recognize five miospore biozones arranged from youngest to oldest as: Classopollis brasiliensis–Afropollis cf. kahramanensis–Dichastopollenites ghazalataensis Assemblage Zone (Late Cenomanian); Elaterosporites klaszii–Sofrepites legouxae–Afropollis jardinus Assemblage Zone (Middle/Late Albian–Early Cenomanian); Pennipollis peroreticulatus–Duplexisporites generalis-Tricolpates Assemblage Zone (Early Aptian–Early Albian); Tucanopollis crisopolensis–Afropollis sp. Assemblage Zone (Barremian) and Appendicisporites cf. tricornitatus–Ephedripites spp. Assemblage Zone (Late Neocomian).The Early Cretaceous Kharita, Alam El Bueib and the Betty formations encountered in the Gebel Rissu-1 well are interpreted to indicate oxic proximal and distal shelf deposits, characterized by type III/IV, V kerogen, which is gas prone but having little potential to produce hydrocarbons. The Upper Cretaceous Abu Roash and Bahariya formations are characterized by a distal suboxic–anoxic and marginal dysoxic–anoxic environment, and their kerogen type III/II indicates gas/oil prone nature. The Bahariya and Kharita Albian–Cenomanian sediments in the present study witnessed the onset of a semi-arid to arid climate, with local or seasonal humid conditions, based on the continuous high abundance of the elaterates pollen and Afropollis-producing plants that inhabited the paleotropical humid coastal plains.  相似文献   

Antibiotic resistant bacteria as bio-indicator of polluted effluent in the green turtles, Chelonia mydas in Oman     

Al-Bahry SN  Mahmoud IY  Al-Zadjali M  Elshafie A  Al-Harthy A  Al-Alawi W 《Marine environmental research》2011,71(2):139-144

Antibiotic resistant bacteria were studied as bio-indicators of marine polluted effluents during egg-laying in green turtles. A non-invasive procedure for sampling oviductal fluid was used to test for exposure of turtles to pollution in Ras Al-Hadd, Oman, which is one of the most important nesting beaches in the world. Each sample was obtained by inserting a 15 cm sterile swab gently into the cloacal vent as the sphincter muscle is relaxed and the cloacal lining is unfolded to the outside. Forty turtles were sampled. A hundred and thirty-two species of bacteria from 7 genera were isolated. The dominant isolate was Citrobacter. Among the isolates 60.6% were multiple resistant to 15 tested antibiotics. The dominant resistance to antibiotics was ampicillin followed by streptomycin and sulphamethoxazole. Sampling oviductal fluid for resistant bacteria to antibiotics is valuable way to assess exposure to polluted effluents during feeding and migratory in turtles. Polluted effluents using bacteria as bio-indicator may influence reproductive potential in this endangered species.  相似文献   

Reservoir associated characteristics using deterministic chaos in Aswan,Nurek and Koyna reservoirs     

H. N. Srivastava  S. N. Bhattacharya  K. C. Sinha Ray  S. M. Mahmoud  S. Yunga 《Pure and Applied Geophysics》1995,145(1):209-217

Nurek, Aswan and Koyna reservoirs were affected by moderate earthquakes with continuing seismic activity. Microearthquake data recorded through local networks have been used to determine the strange attractor dimensions, using deterministic chaos which were found as 7,2, 3.8 and 4.8, respectively. This would imply that while 8 parameters are needed to model earthquakes near Nurek reservoir, only 4 to 5 parameters are needed for the Aswan and Koyna regions. The differences in the strange attractor dimension suggest them to be a measure of seismotectonics around such reservoirs.  相似文献