Study of marine sediments measured by the LIBS technique (Laser Induced Breakdown Spectroscopy)

The accumulation of sediments in the harbours hinders the easy movement of boats. Dredging is a vital activity for the proper operation of harbours. On average, 40 million m3 of sediments are dredged in the harbours of Tunis and 700000 m3 in the harbour of Dakar. Many studies on sediment contamination have revealed high levels of inorganic pollutants due to increasing port activities and their treatments become a major issue for the protection of the environment. The recycling of these sediments is nowadays much regulated and must meet increasingly stringent standards. Thus, a lot of research has been done on the recycling of dredged sediments into building materials. For lower level of pollution they can be reused as embankments. In the case where these levels are too high, they cannot be used as building materials for sanitary reasons and must be discharged offshore, very far from the coast in case of very toxic contamination. Nowadays, it exist several techniques for the analysis and characterization of these sediments, both chemical and physical. Among the physical techniques we have chosen to use the LIBS technique to highlight its promising potential and in particular the possibility of in situ measurements. The main objectives of this study is determining the concentration of heavy metals and comparing them with the regulatory guideline values.