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

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).     

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

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.     

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

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).     

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

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.     

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

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).     

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

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.     

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

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...     

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

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,...     

Landslide susceptibility mapping using machine learning algorithms and comparison of their performance at Abha Basin,Asir Region,Saudi Arabia

The current study aimed at evaluating the capabilities of seven advanced machine learning techniques(MLTs),including,Support Vector Machine(SVM),Random Forest(RF),Multivariate Adaptive Regression Spline(MARS),Artificial Neural Network(ANN),Quadratic Discriminant Analysis(QDA),Linear Discriminant Analysis(LDA),and Naive Bayes(NB),for landslide susceptibility modeling and comparison of their performances.Coupling machine learning algorithms with spatial data types for landslide susceptibility mapping is a vitally important issue.This study was carried out using GIS and R open source software at Abha Basin,Asir Region,Saudi Arabia.First,a total of 243 landslide locations were identified at Abha Basin to prepare the landslide inventory map using different data sources.All the landslide areas were randomly separated into two groups with a ratio of 70%for training and 30%for validating purposes.Twelve landslide-variables were generated for landslide susceptibility modeling,which include altitude,lithology,distance to faults,normalized difference vegetation index(NDVI),landuse/landcover(LULC),distance to roads,slope angle,distance to streams,profile curvature,plan curvature,slope length(LS),and slope-aspect.The area under curve(AUC-ROC)approach has been applied to evaluate,validate,and compare the MLTs performance.The results indicated that AUC values for seven MLTs range from 89.0%for QDA to 95.1%for RF.Our findings showed that the RF(AUC=95.1%)and LDA(AUC=941.7%)have produced the best performances in comparison to other MLTs.The outcome of this study and the landslide susceptibility maps would be useful for environmental protection.     

Cartographie de l’érosion dans le bassin versant de l’Oued Mina en Algérie par télédétection et SIG

Résumé

Dans cette étude, on a fait appel à la télédétection et aux systèmes d’information géographiques (SIG) pour évaluer et cartographier l’érosion hydrique en utilisant l’équation universelle des pertes en sol USLE dans le bassin versant de l’Oued Mina en Algérie. Ce bassin est caractérisé par une grande irrégularité dans les précipitations, une forte pente, une lithologie essentiellement marneuse et une couverture végétale très faible ce qui le rend très vulnérable à l’érosion. L’USLE est la combinaison de six facteurs spécifiques qui décrivent les caractéristiques du bassin versant. Les données de télédétection multi-temporelles et les SIG sont utilisés pour évaluer et cartographier chaque facteur individuellement. L’intégration des cartes thématiques des facteurs du modèle USLE dans le SIG permet de cerner l’impact de chaque facteur dans les pertes en sol, de classer par importance relative les zones d’érosion, et de quantifier les pertes en sol dans le bassin.

Editeur Z.W. Kundzewicz

Citation Toumi, S., Meddi, M., Mahé, G., et Brou, Y.T., 2013. Cartographie de l’érosion dans le bassin versant de l’Oued Mina en Algérie par télédétection et SIG. Hydrological Sciences Journal 58 (7), 1542–1558.