Terfous A.,IMFS |
Hazzab A.,Saida University |
Powder Technology | Year: 2013
This paper presents a relationship for calculating the drag coefficient of a spherical particle. The results obtained were validated using experimental data, including comparison with results from other relationships such as certainty analysis. The validation indicated that the proposed relationship is easier to apply and produces the best results. In addition, a relationship based on the characteristics of both the fluid and the particles was established to calculate directly the settling velocity of a spherical particle in a fluid at rest. The settling velocity values obtained with the proposed relationship were validated using experimental data and the model proved to be reliable and precise. © 2013 Elsevier B.V.
Influence of grain size changes on the turbidity measurement of suspended solid fluxes in watercourses [Influence de la granulométrie des particules sur la mesure par turbidimétrie des flux de matières en suspension dans les cours d'eau]
Thollet F.,IRSTEA |
Le Coz J.,IRSTEA |
Antoine G.,Electricite de France |
Francois P.,IMFS |
And 3 more authors.
Houille Blanche | Year: 2013
Since 2009, Irstea has been measuring suspended sediment fluxes on the Arc river in the French Alps, a great sediment contributor, by using turbidity monitoring systems at four stations; each of them is associated with a discharge measurement system. High frequency turbidity measurement is converted into Suspended Sediment Concentration (SSC) through a SSC = f(turbidity) relation, thanks to sample analysis. Nevertheless a mean relation is not relevant for all flood events for our study site since turbidity sensors do not give the same response for a given SSC. Therefore with the event-scale relation, the uncertainty on the sediment flux can typically reach 30% and sometimes exceed 80% compared with the mean relation while the uncertainty on annual flux remains acceptable (less than 15%) A hypothesis to explain this variable relation is the variation of the SSC grain size in the river. This paper presents the results obtained with an experiment showing the variations of sensitivity of the turbidity sensor to suspensions with different grain size. It isfound to be correlated inversely proportional to the median diameter of the particles. Strategy for managing turbidity calibrations is thus as important as rating curves for hydrometric stations for estimating suspended sediment fluxes. The uncertainty on rating curves is lower especially for the event scale. © Société Hydrotechnique de France, 2013.
Mustapha H.,University of Science and Technology of Oran |
Cherifa H.,Saida University |
Abdelkrim H.,Saida University |
Abdellah G.,IMFS |
Desalination and Water Treatment | Year: 2014
Abstract: In this study, an up-to-date analysis was performed on pollution conditions in the Wadi Saïda drainage basin (North West Algeria). We focused on the water in the streams that drain the basin. The results include a number of quality parameters and give the spatio-temporal variations in surface water pollution indicators over a period of several years. The principal parameters related to the monitoring and evaluation of the pollution of surface water are measured and analyzed. These parameters include the suspended solids, organic matter, nitrate, nitrite in addition to biochemical oxygen demand, and chemical oxygen demand. Analysis and comparison with other basins in Algeria are also performed. In the light of the results, a plan is proposed for the land use and protection of groundwater in Saida. © 2013 Balaban Desalination Publications. All rights reserved.