Concentration of polycyclic aromatic hydrocarbons and quality of sediments in Biétry bay (Ebrié lagoon, Côte d’Ivoire)

The work carried out in Biétry bay did not allow us to determine the levels of polycyclic aromatic hydrocarbons (PAHs) present in the sediments. The aim of this study is to determine the concentration of PAHs and the quality of the sediments in this bay. To achieve this, ten (10) sediment samples were taken during the low-water period. The PAH levels were obtained after the extraction of PAHs using Soxhlet and the analysis of the solutions obtained using gas chromatography coupled with a mass spectrometer (GC-MS). The PAH concentrations are distributed heterogeneously. The average values are generally between 0.003 µg/kg (acenaphthene) and 0.103 µg/kg (pyrene). Heavy PAHs are the most abundant in the sediments. Polycyclic aromatic hydrocarbons mainly come from a pyrolytic source. The sediments of stations b1, b2 and b3 are the most toxic. Correlations have highlighted common developments between certain PAHs. Stations b1, b2 and b3 are the most toxic because their TEQ value is higher than the threshold. Fluorene and fluoranthene are respectively the indicators of the level of deterioration of sediments by light PAHs and heavy PAHs.