Effects of the reopening of the Grand-Bassam inlet on the seasonal dynamics of some trace metals in the superficial sediments from the area II of the Ébrié system

Abstract

The objective of this work was to assess the impacts of the permanent reopening of the Grand-Bassam inlet on the seasonal dynamics of thirteen trace metals in the superficial sediments of the area II from the Ébrié system. In its implementation, the sediment samples were collected over a year (from May 2023 to April 2024). The concentrations of these trace metals were obtained by inductively coupled plasma mass spectrometry (ICP MS) according to ISO 17294-2 after dissolution according to NF X31-147. The results showed a significant input of these metals by meteorological inputs during the rainy, cold, and flood seasons, except for Cr, whose presence in these substrates was mainly related to the strong marine intrusion during the hot season. The modification of the geochemical and physical characteristics due to the reopening of this pass significantly influenced the presence of these trace metals in these substrates during the study period. A reduction in the use of inputs containing high concentrations of trace metals and the efficient treatment of anthropogenic discharges with high metal content in the watershed of this ecosystem should be considered to support the depollution initiated with the reopening of this inlet.