Impact du déversement direct des eaux usées et de drainage dans la nappe libre de l'Oued Souf et son influence sur la qualité des eaux souterraines.

Ces vingt dernières années la région de l'Oued Souf souffre du phénomène de la remontée des eaux de la nappe libre, qui inonde les « ghouts » et les maisons, entrainant de graves problèmes sociaux, agriculturaux et environnementaux. Le réseau d'assainissement qui ne couvre qu'une partie de la ville d'El-Oued rend la situation plus dramatique. Jusqu'a la fin de l'année 2010 une zone, située au Nord-Est de la ville d'El-Oued, a été aménagée pour que les eaux de drainage (système pour rabattre la nappe) et les eaux usées soient déversées directement sans aucun traitement préalable. L'objectif de cette étude est de déterminer l'extension du déversement dans la nappe libre de l'Oued Souf, surtout des eaux usées, et d'évaluer les risques de pollution des eaux souterraines de la nappe libre, plus particulièrement dans la zone de rejet. Six campagnes de mesures hydrochimiques ont été faites : trois durant l'année 2007 (avril, juin et septembre), deux durant l'année 2010 Ganvier et avril) et une en mai 2012 âpres l'arrêt de rejet. L'analyse des échantillons et leur interprétation ont permis l'établissement d'une carte de l'indice de pollution organique. Cette dernière a montre que le terrain a un pouvoir autoépuratoir élève ce qui réduit considérablement les effets de la pollution d'origine organique. Cette tendance est confirmée par les valeurs de la dispersivité longitudinale αL faibles, déterminées au niveau de la zone de rejet. Pour ce qui est des teneurs de certains éléments majeurs naturels (Na+, Ca++, SO4-, Cl-...), celles-ci restent élevées et posent un sérieux problème d'aptitude de ces eaux à l'Irrigation.Mots clés: Nappe libre - Remonte des eaux - Eaux usées - Pollution organique - Oued Souf More than twenty years the region of Oued Soufis suffering from the rising of the water table in the unconfined aquifer, causing flooding of "ghouts" and damaging houses, which induces serious social, agricultural and environmental problems. The sewerage system that covers only a part of the city ofEl-Oued makes the situation more dramatic. Until the end of 2010, the drainage water and wastewater are discharged directly without any preliminary treatment in an area located north-eastern of El-Oued city. Nowadays a wastewater treatment plant was constructed and this area is not more used. The purpose of this study is to determine the extension of the contaminated area by discharged wastewater in the unconfined aquifer and to assess the risk of pollution of groundwater, particularly in the discharging zone. Three hydrochemical surveys were conducted in the discharging area and in its vicinity during 2007 (april, june and september), two during 2010 Ganuary and april) and one in may 2012. The interpretation of analysed samples shows that the pollution has a very short extension and the soil has an important self purifying role that reduces the effects of organic pollution that is shown in the established map of index of organic pollution. The low value of longitudinal dispersivity αL of the soil, evaluated in the discharging area, confirms this trend. We note that the content of some major natural elements such as (Na+, Ca++, SO4-, Cl-...) is high and the use of the groundwater is not advised for irrigation.Keywords: Unconfined aquifer- Rising water level - Wastewater- Organic pollution - Oued Sou

Assessment of the economic viability, environmental, and social impacts of green hydrogen production: an Algerian case study

The impacts of climate change are real and in many parts of the world testify to its harsh reality, including rampant extreme weather events, droughts, heat, wildfires, and flooding which have recorded in places which have not experienced them in recent memory. In the quest to avert such events, there is a growing awareness and demand for sustainable processes and operations. Today, sustainability encompasses a balance between ecological footprint and human development index, taking into consideration economics, the green environment, safety, quality, ethics, diversity and inclusion (D&I), and communities. This article presents some steps that have been taken by Algeria to balance energetic autonomy and sustainable development, and a case study on green hydrogen production employing membrane processes. Algeria’s objective to join the global fight against climate change is to develop its green hydrogen base. Given its resources, including available solar and wind power, seawater desalination plants, building capacity, and its favorable location, it is developing its green hydrogen economy to supply hydrogen, especially to Europe. This presents an opportunity for other developing nations, especially in Africa, to gain from this experience

Dynamique de la nappe et qualités physico-chimiques des eaux souterraines du lac Fetzara (Nord-Est algérien)

Le lac Fetzara est l'un des plus importants lacs de l'extrême Nord-Est Algérien, avec une superficie de 18600 ha. Il a été officiellement classe sur la liste des zones humides d'importance internationale, ce qui impose une protection de ce site. Cette étude a été menée afin d'étudier l'état actuel de la chimie des eaux souterraines et de déterminer l'origine de la salinité. Les résultats analytiques montrent la présence de trois facies chimiques : chlorure sodique, chlorure calcique et bicarbonate sodique. La conductivité électrique des eaux oscille entre 350 et 3500 μS/cm avec de fortes valeurs enregistrées dans les régions Nord-Est (Oued Zied) et au Sud-Est du lac (Cheurfa). L'étude statistique par l'analyse en composantes principales (ACP) montre que les chlorures et le sodium sont les principaux éléments responsables de la forte minéralisation des eaux. Cet excès de minéralisation serait lie éventuellement au lessivage des terrains traverses ou par l'infiltration des eaux de surface qui sont fortement influencées par la forte évaporation en période estivale et les échanges ioniques avec la matrice argileuse.Mots clés: Salinité - Minéralisation - Contamination - Piézométrie - Facies chimique -ACP. Fetzara lake is one of the most important lakes in the North-Eastern of Algeria; with an area of about 18600 ha, it was officially classified on the list of Wetlands of International Importance. This dictates the protection of this location. This study was conducted to examine the current state of groundwater chemistry and the origin of their salinity. The results obtained show a presence of three chemicals facies: sodium chloride, calcium chloride and sodium bicarbonate. The electrical conductivity of groundwater oscillates from 350 to 3500 μS I cm where high values are recorded in the North-East (Oued Zied) and the South-East of the lake (Cheurfa). Statistical study by principal component analysis (PCA) showed that chloride and sodium are the main elements responsible for the high mineralization of the water. This excess of mineralization is due to the leaching of subsurface formations and surface waters infiltration; these are strongly influenced by evaporation and ionic exchanges with clay matrix.Keywords: Salinity - Mineralization - Contamination - Piezometry - Chemical facies - PCA

Fault detection in gears by vibratory analysis

This paper deals with signal processing techniques for non-destructive fault detection on gears . First we describe high resolution spectral analysis techniques, then an adaptive AR method is proposed for fault detection, in the end the sphericity test is presented . Their performance is evaluated on vibratory signais provided by CETIM (on industrial rotating machineries) . The results indicated that the sphericity test out performed the other methods, by scoring a high detection rate, 90 % to 100 % of cases.Dans cet article, nous présentons des applications de techniques de traitement du signal pour le diagnostic précoce de l'écaillage dans les dentures d'engrenages. Nous présentons tout d'abord des méthodes d'analyse spectrale haute résolution, ensuite une méthode de détection de non-stationnarités utilisant la modélisation AR adaptive est exposée, enfin le test de sphéricité est introduit. Des essais sont effectués sur des signaux vibratoires recueillis sur des machines tournantes du CETIM. Les performances du détecteur basé sur le test de spéricité sont analysée

Comparison between solar utilization of a closed microalgae-based bio-loop and that of a stand-alone photovoltaic system

This study compared the solar energy utilization of a closed microalgae-based bio-loop for energy efficient production of biogas with fertilizer recovery against that of a stand-alone photovoltaic (PV) system. The comparison was made from the perspective of broad life cycle assessment, simultaneously taking exergy to be the functional unit. The results indicated that the bio-loop was more environmentally competitive than an equivalent stand-alone PV system, but had higher economic cost due to high energy consumption during the operational phase. To fix the problem, a patented, interior pressurization scheduling method was used to operate the bio-loop, with microalgae and aerobic bacterial placed together in the same reactor. As a result, the overall environmental impact andtotal investment were respectively reduced by more than 75% and 84%, a vast improvement on the bio-loop

Evolution d'eaux agressives mises au contact du carbonate de calcium : influence de la temperature, modelisation

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Collectivism Vs Individualism in the American Farmers Protest During the Thirties. In John Steinbeck’s The Grapes of Wrath (1939) and Of Mice and Men (1937).

59p.;30cm.(+cd)Our aim through this memoire is to study the two philosophies of Collectivism and individualism in the light of John Steinbeck’s novels The Grapes of Wrath (1939) and Of Mice and Men (1937) in order to shed light on the conflict between the two opposing philosophies in the period of the 1930s. In fact, due to the effects of the Great Depression (1929) and the Dust Bowl (1935) in the United States of America, American farmers faced difficult moments. To overcome their plight, they found no solution (means) than acting and protesting collectively believing that collectivism was the only way to stop the abuses of government and the greediness of businessmen at that time. Within the collective bodies, they formed each one of them looked for his/her self-interests in the actions they organized. This proves that despite their collectivity, the spirit of individualism they lived for so many years was still engraved in their minds. The clash between the two philosophies of collectivism and individualism is well illustrated in John Steinbeck’s novels The Grapes of Wrath (1939) and Of Mice and Men (1937) which reflect well the misfortune and despair of the American farmers who tried by all the means necessary; including the creation of organizations so that to establish unions and agreements to put an end to economic and social problems, such as unemployment, homelessness and famine. So, this memoire identifies how characters in both The Grapes of Wrath and Of Mice and Men acted collectively but at the same time looked for their self-interests. To reach our purpose, we rely on Jean Jacques Rousseau’s theory of collectivism mentioned and discussed in The Social Contract (1762) and Alexis DeTocqueville’s theory of individualism mentioned and discussed in Democracy in America (1835)