Caractérisation physico-chimique des eaux usées d’abattoir en vue de la mise en oeuvre d’un traitement adéquat : cas de Kénitra au Maroc

Notre objectif principal est de caractériser les eaux usées d’abattoir municipal de la ville de Kénitra (Maroc) et de recommander un traitement adéquat permettant leurs réutilisations, réduisant ainsi les nuisances que subit le milieu récepteur (Oued Sebou) et de remédier aussi à la perte de cette source hydrique en matières valorisables. La caractérisation physico-chimique des eaux usées brutes a révélé que ce rejet liquide est très chargé en matière organique en terme de DCO (Moy. = 219,52 mg/L ±51,07), en DBO5 (Moy. = 181,34 mg/L±30,04), en MES (Moy. = 482 mg/L ±222,7) et en matière minérale exprimée en terme de Chlorures (Moy. = 237 mg/L ±109,6), en Conductivité électrique (Moy. = 1360,5 μs/cm ±1120,8) et en Alcalinité exprimée en CaCO3 (Moy. = 201 mg/L ±74,2) avec un pH de 7,5 (±0,8). Les teneurs moyennes en Nitrates et en Orthophosphates respectivement de l'ordre de 1,74 mg/L (±2,7) et 0,08 mg/L (±0,1). Malgré que ces eaux usées présentent une charge organique élevée (rapports DBO5/DCO = 0,83 et MES/DBO5 = 2,66), elles présentent une biodégradabilité satisfaisante. L’examen de rapport DCO/DBO5 = 1,21 souligne bien le caractère biodégradable des eaux usées de l'abattoir municipal de Kénitra auxquelles un traitement biologique paraît tout à fait convenable. Cependant, il faut tenir compte les eaux usées domestiques mélangées avec les effluents de l'abattoir. Il existe une corrélation hautement significative entre la DCO et la DBO5 de nos échantillons d’eaux usées (R2= 0,93 et y = 1,2689x + 23,814). Par ailleurs, la corrélation établie entre l’oxygène dissous et la DBO5 montre un R2= 0,75 (y = 0,0057x + 0,7964).Mots-clés : eaux usées, abattoir, paramètres physico-chimiques, traitement, Kénitra

Position resolution and particle identification with the ATLAS EM calorimeter

In the years between 2000 and 2002 several pre-series and series modules of the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon and pion beams. The performance of the calorimeter with respect to its finely segmented first sampling has been studied. The polar angle resolution has been found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection has been measured to be about 3.5 for 90% photon selection efficiency at pT=50 GeV/c. Electron-pion separation studies have indicated that a pion fake rate of (0.07-0.5)% can be achieved while maintaining 90% electron identification efficiency for energies up to 40 GeV.Comment: 32 pages, 22 figures, to be published in NIM

Population dynamics of cattle ticks in Gharb Region in Morocco

This study was conducted in the rural town of Sidi Boubker El Haj in Gharb Region, Morocco, from November 2009 to October 2010. The objective was to identify the various tick species collected on cattle, to monitor their seasonal dynam­ics and determine their abundance and infestation variability according to the age and sex of the hosts. Thirty cattle head were monitored and sampled monthly for a year. A total of 6899 ticks were collected. Identification revealed nine species belonging to five genera with the following prevalence: Rhi­picephalus bursa 28.61%, Ixodes ricinus 26.39%, Hyalomma lusitanicum 23.33%, Rhipicephalus turanicus 14.44%, Hya­lomma detritum detritum 13.06%, Rhipicephalus sanguineus 1.39%, Hyalomma marginatum marginatum 1.11%, Derma­centor marginatus 1.11% and Haemaphysalis sulcata 0.83%. I. ricinus was active in winter, R. bursa, Hyalomma lusitanicum and R. turanicus in spring, and Hyalomma d. detritum in sum­mer. R. sanguineus, Hyalomma m. marginatum, D. margina­tus and Haemaphysalis sulcata were less prevalent and their presence on cattle may be referred to as occasional parasitism. This study on tick population dynamics may help implement a strategy for tick control and tick-transmitted disease control, taking into account the parasite seasonal activity, parasitic loads, and infestation rates

Etude physico-chimique et parasitologique des eaux usées destinées à l\'irrigation du périmètre péri-urbain de Fouarat (Kénitra, Maroc).

Les eaux usées de la commune urbaine de Saknia-Fouarat (Kénitra) sont rejetées sans aucun traitement préalable dans le lac Fouarat. Celles-ci sont en partie réutilisées pour l\'irrigation du périmètre péri-urbain de cette zone à vocation agricole. La caractérisation physico-chimique des echantillons a révélé un pH proche de la neutralité et des teneurs en sels relativement importantes. La teneur en chlorures a été de 112,5 mg/l. La charge polluante engendrée par ces effluents urbains a été comprise entre 24 et 124 mg/l pour la DBO5, 110,40 et 418,33 mg/l pour la DCO et entre 350 et 615 mg/l pour les MES. Ces paramètres de pollution ont été relativement faibles, comparativement à la moyenne des concentrations habituellement rencontrées pour les eaux usées urbaines du Maroc. Le rapport DCO/DBO5 a été de 3,48. Cette valeur élevée montre que les eaux usées de la commune urbaine de Saknia-Fouarat sont caractérisées par une pollution inorganique liée, notamment, au rejet des effluents d\'industrie textile raccordée au collecteur. L\'analyse parasitologique montre une forte contamination de ces eaux usées par les oeufs d\'helminthes, soit 32,4 oeufs/l, concentration nettement supérieure aux normes de l\'OMS (Organisation Mondiale de la Santé) relatives aux eaux destinées à l\'irrigation non restrictive des cultures. Les effluents constituent donc un risque environnemental pour la nappe phréatique sous-jacente exploitée par l\'ONEP (Office National de l\'Eau Potable) et pour les eaux du lac Fouarat. En conclusion, le traitement préalable de ces rejets est vivement recommandé, avant leur rejet dans le lac Fouarat pour usage comme eau d\'irrigation des cultures maraîchères.Effluents of the Saknia-Fouarat urban district (Kenitra city) are rejected in the Fouarat Lake without prior treatment. Part of the effluents is used to irrigate the peri-urban perimeter of this agriculturally-rich area. The physico-chemical characterization of these effluents revealed that pH is close to neutrality with relatively high salt content. Chloride concentraqtion was of about 112.5 mg/l. The polluting load generated by these urban effluents was between 24 and 124 mg/l for the BDO5, 110.4 and 418.33 mg/l for the COD and between 350 and 615 mg/l for suspended particles. All these pollutions parameters were relatively low, as compared to the average concentrations of the usual moroccan urban effluents. The calculated COD/BDO5 ratio was 3.48. This high value shows that these wastewaters are characterized by an inorganic pollution related to effluents rejection by the textile industry connected to the main collector. The parasitological characterization of the effluents shows a strong contamination by Helminths parasites eggs (32.4 eggs/l). This concentration largely exceeds the WHO standars concerning water used for non-restrictive irrigation of the cultures. Our results show that effluents used for irrigation cultures in the Fouarat perimeter induce an environmental risk for the subjacent ground water exploited by the ONEP and for the Fouarat Lake water consequently, we highly recommend the treatment of these effluents before their rejection in the Fouarat lake and the in use for irrigation. Keywords: Pollution, eaux usées, physico-chimie, Helminthes, lac Fouarat, MarocAgronomie Africaine Vol. 19 (3) 2007: pp. 251-26

Response uniformity of the ATLAS liquid argon electromagnetic calorimeter

The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 5 ‰ and typical global constant terms of 6 ‰ are measured for the barrel and endcap modules. © 2007 Elsevier B.V. All rights reserved

Response uniformity of the ATLAS liquid argon electromagnetic calorimeter

Accepted by NIM AThe construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 0.5% and typical global constant terms of 0.6% are measured for the barrel and end-cap modules