TIEMOKO Tonga Paul

Affiliated project: Institut National Polytechnique Félix Houphouët-Boigny INP-HB

Thesis supervisor: Kouassi Ernest AHOU
Université Félix Houphouët-Boigny UFHB
akouassiernest@gmail.com

Thesis co-supervisor: Gbele OUATTARA
Institut National Polytechnique Félix Houphouët-Boigny INP-HB
gbele.ouarttara@yahoo.fr
Ouattara.gbele@inphb.ci

Start date: November^1, 2020
Anticipated date of thesis defense: October 31, 2023
ORCID profile: 0009-0003-8881-0760

Project title:
Study of metal pollution from gold-panning sites in the Lake Taabo watershed (Côte d'Ivoire) and its impact on the quality of water resources.

Summary of scientific project: Most gold deposits in West Africa are located in geological contexts where primary mineralization is often associated with sulfides. Their exploitation produces waste heaps whose open-air storage can be a source of metallic pollution in receiving environments. The aims of this research project are to sample and analyze mine site discharges, determine the predominant toxic metals and establish a possible link with the pollution of water resources (aquatic sediments and fishery products), which will also be sampled and analyzed. Ultimately, this project should provide scientific evidence of the harmful effects of neglected mining discharges on ecosystems and the health of populations, and offer tools for solving the problem of sustainable management of mineral resources.

Summary of results obtained :

This study was carried out at gold panning sites in the Yaouré, Toumodi and Oumé-Hiré regions of Côte d'Ivoire. Its aim is to determine the toxic metals generated by these sites, with a view to preventing possible metal contamination and/or pollution of the region's water resources, which supply freshwater fish products to local populations. To this end, a sampling campaign was carried out and 58 composite samples of mining waste were taken and analyzed by XRF spectrometry, ICP-MS. Statistical analysis was carried out to determine the distributions and correlations between these TMEs. Levels of contamination and/or pollution were determined by calculating various indices (enrichment factor, geo-accumulation index, concentration factor and degree of contamination) on the basis of reference concentrations of ETMs in the upper continental crust. These TMEs were found in abundance in water and sediments in the study area. The sites concerned should be subject to environmental monitoring to prevent potential ecological risks to the region's waters, and in particular to Lake Taabo downstream.