Assessment of harbor sediment contamination for a path to valorize dredged material

Abstract

Annually, over one billion m3 of sediment are dredged worldwide to ensure safe access for ships to harbors. Dredged sediment from harbors, considered as waste, presents an interesting opportunity for sustainable development projects by valorizing it as construction material. Characterizing dredged material is a crucial step to confirm the feasibility of reusing marine sediment and identifying potential valorization pathways. However, previous studies have primarily focused on investigating dredged sediment properties at a physical, geotechnical, and mineralogical level, with limited analysis of the presence of chemical contaminants, despite their impact on assessing sediment quality as a substitute for construction aggregate. The aim of this paper is to evaluate the contamination of marine sediment dredged from Safi harbor, located in central Morocco in an urbanized and industrialized area. Determining the contaminant content in the sediment is a prerequisite for the valorization process. To achieve this objective, the chemical characteristics of sediment collected from six different sampling points are studied. On one hand, the concentrations of the following trace metals are measured: Cadmium (Cd), Arsenic (As), Chromium (Cr), Nickel (Ni), Lead (Pb), Copper (Cu) and Zinc (Zn). On the other hand, Total Petroleum Hydrocarbons (TPH) and Total Organic Carbon (TOC) are analyzed. The results show that the reference values for the studied contaminants are not exceeded at the sampling points located in the port access channel. These findings indicate the potential for valorizing dredged sediment as an alternative source of construction materials.

Keywords

• Dredged sediment
• Valorization
• Chemical contaminants
• Trace metals
• Reference values