Abstract
In the coastal areas, harbors are key elements of commercial and tourist activities. Their maintenance and expansion requires regular removal of sediment that has accumulated over time in channels and other traffic or mooring areas. This dredging operation is responsible for large volumes of sediments. In France more than 50 millions m3 of marine sediments are dredged per year. Due to human activities and inland runoffs sediments can be contaminated either in metal and/or organic components. Their particle size properties depend on the conditions of sedimentation and mobilisation in the harbor seafloor. Legislation on the dredged sediments is getting more and more restrictive, prohibiting sea disposal and promoting back inland for reuse, valorisation or elimination. In many management streams, salinity of the fine-grained sediments is challenging. In fact, marine sediments have high amounts of chloride and sulfate contents those are incompatible with reuse and technological treatment processes. This work deals with the case studies of two Mediterranean harbors in the framework of a major dredging project (mutual dredging of Aigues-Mortes) and focuses on the treatment of their salinity, mainly of their high chloride contents, by phytoremediation. Chloride phytoextraction is mainly addressed with Arundo donax in various cultural modalities. The tolerance to salinity of this species, that has a fast growing and has many commercial use, its capacity to take up chloride, and its desalinization potential are determined.