ewash-ti Outils de lecture

The problem of drinking water supply in Abidjan Autonomous District is acute. The objective of this study is to assess the quality of Aghien Lagoon waters with a view to their use to make up drinking water deficit. To do this, French Association of Standardization methods were used for determination of various parameters of 48 samples of lagoon waters. Piper diagram was used for waters hydrochemical classification, as well as Principal Component Analysis (PCA) for determining the processes responsible for their mineralization. The mean values of the physical and chemical parameters (pH, Ca₂⁺, K⁺, Cl^-, Na⁺, Mg²⁺, PO₄^3-, SO₄^2-, CE, TDS, DBO₅, NO₃^-, NO₂^-, Cd, Pb, Zn and Cu) comply with the French values required for surface fresh waters intended for drinking water production.

On the other hand, mean concentrations of NH4 + (36.88 mg / L) and Fe (1834.48 μg / L) and turbidity (14.98 NTU) are higher than these regulatory limits. Aghien lagoon waters consist of 54.55% of chlorinated water and 45.45% of bicarbonate water. The chemistry of these waters is controlled by rainfull, the weathering from rocks of the watershed, decomposition of organic matter, fertilizers from agricultural activities, and the weathering of silicate minerals from the underlying sediments. The latter seems to play a minor role in hydrochemistry, due to the relatively short residence time.

On the whole, Aghien Lagoon waters could be used for the production of drinking water.