Gaseous air pollution background estimation in urban,suburban, and rural environments     

Mufreh S. Al-Rashidi  Mohamed F. Yassin  Nawaf S. Alhajeri  Marium J. Malek 《Arabian Journal of Geosciences》2018,11(3):59

There is a great demand for estimating the ambient air pollutant background concentrations in order to assess the effectiveness of different emission control strategies. In this paper, the background concentrations of four pollutants, namely sulfur dioxide (SO₂), nitrogen oxides (NOx), carbon monoxide (CO), and ozone (O₃) pollutants in urban, suburban, and rural environments were investigated using Kolmogorov–Zurbenko (KZ) filter technique. Air quality data from monitoring stations over a period of 4 years (2007–2010) was analyzed for three locations in Kuwait, namely urban, suburban, and rural. The spatial and temporal (daily, weekly, and monthly) variations of the four pollutants were analyzed. The results show that the levels of ambient air pollutant background concentrations were high in the urban site compared to suburban and rural area. The diurnal variation of SO₂ concentration showed an early morning peak, while the diurnal variation of NOx concentration constituted has two peaks, one was in the early morning hours (5 to 8 a.m.) and the second was in nighttime hours (8 to 11 p.m.). These two peaks were observed at all three locations. The monthly background NOx concentration reached a maximum in winter and minimum in summer. Diurnal variation of CO concentration showed a similar trend to SO₂ concentrations in all three locations. Because of the photochemical reactions that occur in the atmosphere, the background concentration of O₃ showed an inverse relation with respect to background concentration of NOx.  相似文献   

Hydrogeological characterization of a carbonate aquifer using geophysical and geochemical approach: case of the Krachoua Formation in Tataouine area,Southern Tunisia     

Mouez Gouasmia  Houyem Khorchani  Abdelkader Mhamdi  Ferid Dhahri  Mohamed Soussi 《Arabian Journal of Geosciences》2018,11(24):786

An integrated hydrogeological investigation involving geological surface data, well data (lithostratigraphical and piezometric data) and the vertical electrical sounding (VES) method was carried out in Tataouine area, Southern Tunisia to characterize the hydrogeology and the geochemistry of the Krachoua Formation aquifer. The electrical data were used to differentiate lithostratigraphic units and characterize their hydrogeological potentialities. Major elements contents within groundwater samples were assessed and some plots and diagrams have been established in order to investigate the hydrochemical properties of this aquifer and the origin of its mineralization. The Krachoua aquifer exhibits a general drawdown of the piezometric level from 2004 to 2015 reflecting a dramatic decrease in groundwater resources due to increased groundwater abstraction during the last decades. Flow directions shows that the recharge of this aquifer considered as a free aquifer is directly ensured by rainfalls over the outcropping fractured limestones. The geometry of the Krachoua Formation aquifer is tectonically controlled and structured in horst and graben features that impacted greatly the hydrogeology and the hydrodynamics of the area. Subsequent thickness and facies variations within this aquifer influenced the reservoir quality and the groundwater flows. The increased values of salinity to the northwest of the study area seems to be mainly related to the dissolution of the Upper Liassic gypsum of Mestaoua Formation which outcrops widely and can be dissolute easily by meteoric water and contaminate the Krachoua aquifer. This fact is also supported by the sulfated and calci-magnesian chloride facies of this aquifer related to the dissolution of evaporitic rocks (gypsum, anhydrite, and halite). However low salinity values are recorded within the zone where these evaporitic rocks are relatively deep.  相似文献   

Fungal biodiversity in sewage water under the effect of calcium hydroxide and hydrogen peroxide into two-steps treatment     

R. A. Mohamed  W. A. El-Said  A. K. Ibrahim 《International Journal of Environmental Science and Technology》2018,15(5):957-967

Microorganisms, organic matter, heavy metals are the main pollutants in sewage water. The increasing water demand pressurized people to use the sewage water. Different systems, chemicals and physical treatments were used in sewage water treatment. The aim of this work is to study the effect and correlations of primary (Ca(OH)₂ filtration and H₂O₂) and secondary (dissolved oxygen, organic matter, conductivity, pH and OD) factors on fungi present in sewage water in addition to proving the sequence of the system used in the current study. After treatment, fungi were examined, identified on Czapek agar and analyzed using multivariate tools (CANOCO: DCA and CCA) and R software. The treatment includes two main steps: liming filtration and oxidation, respectively. All parameters were negatively or positively correlated (organic matter, pH, conductivity %, optical density, fungal CFU ml^?1, dissolved oxygen). Heavy metals were decreased due to the application of Ca(OH)₂ and H₂O₂, respectively. There were two main groups of fungi. The larger was correlated with the organic matter, whereas the second was tolerating calcium hydroxide concentrations. Aspergillus sydowii tolerated hydrogen peroxide (0.2 mll^?1(33%); Ca(OH)₂, 0.25 gl^?1). Sequential steps treatment was healthy and economically efficient. The proposed system improved water characteristics. The recommended amount of Ca(OH)₂ and H₂O₂ was 0.25 gl^?1 and 0.2 mll^?1(33%), respectively, and can remove more than 99.9% of fungal CFUs. The current study minimized the optimum dose of hydrogen peroxide used in the disinfection of sewage water from 1.5 (Mohamed in Chem Eng J 119:161–165, 2006) to 0.2 mll^?1 of H₂O₂ (the current study).  相似文献   

Assessment of Aquifer Storage and Recovery (ASR) feasibility at selected sites in the Emirate of Abu Dhabi,UAE     

S. Sathish  Mohamed M. Mohamed 《Environmental Earth Sciences》2018,77(3):112

Aquifer storage and recovery (ASR) is considered as a strategy for the storage of water to ensure a sustainable water supply in the Abu Dhabi emirate. Earlier investigations have been conducted, and two sites were proposed for the installation of ASR in the surficial aquifer. Recently, the site located in the center of Abu Dhabi (sand dune area) was executed, and the second site is undergoing the pilot phase of the study. However, the performance and influence of the regional groundwater system may vary depending on regional hydrogeological characteristics, which have not been investigated. Hence, this study attempts to understand the feasibility of the proposed ASR sites in the surficial aquifer using a regional model developed by the finite-difference approach with an accuracy of 0.28 m mean residual difference. Additionally, six sites were selected on the basis of the literature and aquifer parameters and were investigated for their suitability for future ASR installation. Six cycles of injection and recovery at various rates were analyzed at each ASR site by using a transient calibrated model until the end of the year 2030. The area of influence is axisymmetrical in the sand dune area and non-symmetrical in the east and northeastern areas because of the steep topography and groundwater table gradient. At the sites that possess a non-symmetrical influence, the area of influence is always high upstream of the groundwater flow. Heterogeneity-induced variation in the fluctuation of the groundwater table is noted in all sites. Even with 100% recovery, the groundwater table did not reach the ambient groundwater table during the recovery period. This finding confirms the contribution of regional groundwater to the site during recovery. All sites selected for future ASR installation, except site 5, are capable of storing the volume needed to meet expected water demand. Site 2 is considered the most suitable site for ASR installation in the future. This study will facilitate the scientific communities and authorities in understanding the feasibility of ASR installation for sustainable water storage and supply in the Abu Dhabi emirate.  相似文献   

Deformed dike swarms as an implication of transpression deformation in Western Arabian shield,Wadi Fatima,Saudi Arabia     

Mohamed I. Matsah  Haitham M. Baggazi  Abdelhamid El Fakharani  Mohamed K. El-Shafei 《Arabian Journal of Geosciences》2018,11(22):727

Utilization of satellite images and field observations of dike swarms in pre-Fatima basement show that these dikes are older than the overlaying Fatima Formation. Dikes digitization and orientation analysis on satellite images show that the prevailing trend of the dikes is ENE-WSW. The granitic rocks of pre-Fatima basement and its hosted dikes expose evidences of completely a different deformation regime from the overlaying Fatima Formation. These evidences include shearing, dextral shear indicators, isoclinal folds, deflection and rotation of crystals, mineral elongation, and mylonitic and gneissose textures. Strain analysis results of using Fry method on quartz and feldspar grains support the presence of deformation in these ENE-WSW dikes. These results gave a strain ratio of 2.1:1.3:1, which suggest an amount of 40% stretching in the ENE-WSW direction parallel to the dike walls, and an amount of 30% shortening in the NNW-SSE direction. Mesoscopic and microscopic scale structures confirm the existence of dextral ductile-brittle shearing followed the emplacement of the dikes and before the pure shear deformation that caused the thrusting and folding of Fatima Formation. This ductile-brittle deformation is correlated with the dextral transpression that formed the Fatima Shear Zone (FSZ).  相似文献   

Conflicts and water governance challenge in irrigated areas of semi-arid regions     

Jamel Ben Nasr  Mohamed Salah Bachta 《Arabian Journal of Geosciences》2018,11(23):753

Agriculture in arid and semi-arid regions faces two of the principal global challenges: sustainability and water scarcity in the context of climate changes. To overcome the water scarcity constraint, Tunisia adopted different strategies and policies. Since 1989, it has embarked on a policy of decentralization and participatory water management in irrigated areas “IA.” This policy has led to the state disengagement in favor of collective water management. Since then, water management becomes a task of irrigator associations. These associations have experienced a series of transformations ranging from “collective interest associations: CIA” to the current form “Development Agricultural Groups: GDAs.” In spite of these institutional changes, GDAs are suffering from several problems impeding their functioning such as budgetary deficit, conflicts between stakeholders, leaving of irrigated activity by some farmers, and inequality. The current situation of GDA and most IA hypothesizes the existence of local governance problems; these governance problems are causing a performance decrease in IA. The analysis of the interdependence between governance and performance of irrigation water management, in Nadhour IA, is the main aim of this paper. To conduct this analysis, the strategic analysis approach was adopted. Assuming that IA forms a concrete action system, the analysis of structured games between actors allowed assessing their power, convergence, divergence, and ambivalence. Results confirm the hypothesis of a significant effect of governance problems, including political source, on the performance of water management in IA.  相似文献   

Petrology of lower-middle Miocene Zoumi Flysch Fm. (Mesorif sub-domain,Rif belt,Morocco): first evidence of mixed mode provenance and geodynamic setting     

Mohamed El Mourabet  Ahmed Barakat  Jamila Rais  Mohamed Najib Zaghloul  Achraf Atouabat 《Arabian Journal of Geosciences》2018,11(9):209

The Zoumi Basin was generated in a collisional tectonic setting during the Lower-Middle Miocene. The syn-orogenic flysch deposits of the basin have been well investigated by petrographic and geochemical studies to characterize the composition, source to sink routing system, and tectonic setting of the Zoumi flysch. Forty-three sandstone samples and 45 mudstone samples have been gathered from six measured stratigraphic sections. These samples have been analyzed using XRD, XRF, inductively coupled plasma-mass spectrometry (ICP-MS) for mudrocks and petrographic investigation for sandstones. The Lower-Middle Miocene Zoumi flysch is defined as sublitharenites and quartzarenites according to mineralogical content. Detrital grains are commonly subangular to subrounded, poorly sorted, and rich in quartz grains. Point counting modal analysis leads to craton interior and recycled orogen provenance with significant first-cycle sediment supply and low sedimentary recycling. Several chemical ratios (Al₂O₃/TiO₂, La/Th, Cr/Th, Th/Sc, Zr/Sc) as well as chondrite-normalized REE patterns with flat HREE, LREE enrichment, and negative Eu anomaly suggest a dominant felsic rock sources. However, V-Ni-La*4, V-Ni-Th*10, and Th/Sc vs. Cr/Th plots do not exclude a mafic supply source nature which is evidenced by numerous ophiolitic outcrops scattered throughout the Mesorifan Subdomain (Mesorifan Ophiolitic Suture Zone).  相似文献   

Improving the existing roadway tunnels capacity by adding new tunnels—a structural approach     

Mostafa Zaki AbdElrehim  Mohamed A. Eid  Osama Moshref 《Arabian Journal of Geosciences》2018,11(5):89

The roadway tunnel is considered a good solution for the success of modern roadway networks. It can help to overcome possible traffic congestion and considerably reduce journey time. The continuous growth of traffic volumes leads to increase congestion and decrease safety. This leads to the need for extra tunnel space. The extra tunnel space can be achieved either by the widening of the existing tunnel or by adding a new one. The choice of the suitable method is dependent on many factors like tunnels alignment, site conditions, construction method, tunnel operation, risk assessment…etc. The current research investigates the second alternative through a specific case study as an example. The method comprises adding two new tunnels to an existing twin roadway tunnels. The investigated problem considers the new tunnels to be added vertically or horizontally. The influence of the new tunnel construction on the existing tunnels is investigated considering both the variation of relative position and spacing distance in a parametric study context. Several numerical models are employed to check the construction sequence and the tunnelling safety. These models are used to evaluate the induced stresses in surrounding ground for two different soil types, straining actions in tunnels’ liner and deformations of both ground and liner. The result demonstration shows how to find out the minimum practical and safe spacing distance between the driven new tunnels and the existing ones without the need for the relatively expensive soil strengthening techniques.  相似文献   

Correction to: Uncertainty in the prediction and management of CO2 emissions: a robust minimum entropy approach     

Qu  Shaojian  Cai  Hao  Xu  Dandan  Mohamed  Nabé 《Natural Hazards》2021,109(3):2439-2459

Natural Hazards - The Mahi—one of the major rivers in Western India—is subject to frequent major flooding, which severely affects the local economy and infrastructure. Little has been...  相似文献   

Development of a GIS-based alert system to mitigate flash flood impacts in Asyut governorate,Egypt     

Mohamed  Soha A. 《Natural Hazards》2021,108(3):2739-2763

Natural Hazards - Egypt is one Arab country that is vulnerable to flash floods caused by heavy and intensive rainfall. Different locations in Egypt are vulnerable to the hazards of flash floods,...  相似文献