ELSEVIER Nuclear Instruments and Methods in Physics Research B 95 (1995) 102-106 B Beam Interactions with Materials & Atoms PIXE and RBS analysis of sediments from E1-Kansera barrage on Oued Beht river in Morocco F. Benyaich a, L. Torrisi b,* M.Z. Benabdellah a, M. Derraz a a Universit~ Moulay Isma~l, BP 4010 Beni M'Hamed, Mekn~s, Morocco b Uniuersith di Messina, Ctr. Papardo, 31. 98166 S. Agata, Messina, Italy Received 31 August 1994 Abstract Elemental analyses of sediments from the barrage E1-Kansera on the river Oued Beht in Morocco, are reported. These analyses were performed by means of proton induced X-ray emission (PIXE), and Rutherford backscattering spectroscopy (RBS). The RBS analysis allowed the determination of the sediments matrix composition, which was used for the PIXE analysis. The quantitative analyses of the PIXE spectra were performed by using the binary encounter approximation (BEA) for the inner shell ionization cross section. Preliminary results are presented, and a comparison with literature data is discussed. 1. Introduction 2. Experimental Sediments in rivers estuaries, lakes and barrages have a high capacity to concentrate and retain toxic trace ele- ments. Heavy metals may be natural constituents of the sediments, i.e. they come from the rocks and soils via their geochemical mobility. They also can have anthropogenic sources, in which case they are incorporated into the sediments as artificial pollutants coming from urban, in- dustrial or agricultural releases and wastes. Developed and developing countries are paying an increasing interest to environmental sciences due to the evident impact industrialisation and urbanisation have on the environment and the natural resources. In particular for developing countries, given their geographical and climatic situation, the disposability, the storage and the distribution of good quality waters are matter of great concerns. In the field of the environmental sciences, among the many multi-elemental analysis techniques, ion beam analy- sis (IBA) has demonstrated to be a powerful tool for monitoring the elemental composition and trace elements detection in soils, sediments, water and air particulates [1-3]. In this paper we report on the elemental concentra- tions of the sediments of the barrage E1-Kansera in Mor- roco, measured by P1XE (proton induced X-ray emission) and Rutherford backscattering spectroscopy (RBS). * Corresponding author. The analysed sediments samples were taken from the basin storage of the barrage E1-Kansera in Morocco. This barrage is located in the centre of Morocco near a small urban agglomeration; Khemisset city in a farming region. A schematic representation of the barrage and the incom- ing rivers is drawn on Fig. 1. The barrage is filled by the river Oued Beht and a small affluent Oued Khemisset river. This barrage supplies Khemisset city and its region with potable water and waters for agricultural uses. The waste waters rejected from Khemisset city are drained by the small affluent Oued Khemisset which feeds them back into the main river Oued Beht. Oued Khemisset is a small affluent and accounts for less than 10% of the total water flux drained by Oued Beht. The analysed sediments were taken from seven (7) sites ($1 to $7) in the basin storage as indicated in the insert of Fig. 1. The sediments were collected from the superficial layer of the sediments, i.e. the uppermost 3 cm. For each site the sediments were collected from three points few meter apart from each other and then mixed in order to prepare homogeneous samples. The samples collection was performed in the same day, in the order of the numerical sequence of the inset of Fig. 1. The sediments were then dried at 60°C and homogenised in an agate mortar. Thick samples were pelletised into 1 cm diameter disks, their mass was typically 250 mg. To avoid contamination of the sediments during the preparation stage, both faces of the compression die were covered with thin disks of polymer (polytetrafluoroethylene). 0168-583X/95/$09.50 © 1995 Elsevier Science B.V. All rights reserved SSDI 0168-583X(94)00327-0