COMPARATIVE STUDY OF THE PHYSICO-CHEMICAL QUALITY OF THE WATER OF FOUR LAKES OF THE FERKESSEDOUGOU DAM (NORTH OF COTE DIVOIRE)

Runoff from the catchment areas of the reservoirs is partly responsible for the chemical quality of the water. The main objective of this study was to compare the physico-chemical quality of the waters of four lakes in the sub-county of Ferkessedougou located in the north of Cote dIvoire. After application of the referenced analytical methods, the contents of chemical elements were subjected to statistical processing, mainly principal component analysis (PCA). The study revealed a categorization of the water in the reservoirs. On the whole, the water in the reservoirs is poorly mineralized, thus justifying a low electrical conductivity (66.67 to 138.04 µS/cm). The Bakaryvogo lake, richer in dissolved elements, is opposed to the Korobelekaha and Dekokaha lakes, which have the lowest electrical conductivity, unlike the others. The lake of Sepenediokaha is distinguished by turbid waters rich in organic matter (COD) and suspended solids (SS). This study provided an overview of the quality of the water, which remains a function of the activities in the catchment areas. Furthermore, the waters of these reservoirs are potentially threatened by the phenomenon of eutrophization given the levels of nutrients measured. Indeed, the concentrations of nitrate, nitrite and phosphorus, although lower than the thresholds allowed by the WHO, are significant. There are also significant levels of phosphorus. In addition, the average Fe2+ content measured (0.78 mg/L) is above WHO standards.