Characterization and Typology of Aghien Lagoon waters (SouthEast of Cote d'Ivoire): Potential Resources for Drinking Water Production

Abstract

The objective of this study was to evaluate the physico-chemical quality of the Aghien lagoon in view of its consomptions as drinking water. The physico-chemical parameters were measured and water sampling were carried out monthly from June 2014 to May 2015 in eleven (11) sites well defined around Aghien lagoon. The parameters were determined using standard methods as defined by the French Association of Standardization (AFNOR). The Seasonal values of temperature, pH, turbidity, electrical conductivity, percentage dissolved oxygen and TSS in Water,falls to the following 26.31-29.76 °C; 6.95-8.03; 16.74-41.05 NTU; 63.15-109.11 μS/Cm; 63.91-100.21% and 8-31.18 mg/L respectively. ANOVA analysis result showed no significant differences (p>0.05) between seasons (dry and rainy) as for temperature, pH and electrical conductivity in all stations. For turbidity, dissolved oxygen and TSS, there was a significant difference between seasons. Seasonal concentrations of nutrient salts in water (mg/L) ranged from 0.01 to 0.14 for NO2 ; 0.48 and 1.93 for NO3 ; 0.06 and 1.90 for PO4 3. Seasonal variations showed a significant difference (p <0.05) for nitrate. The mean values of most parameters studied during both seasons are generally below the standard values recommended by the World Health Organization and SEQ Littoral. The calculated COD / BOD5 ratio showed that the water in the Aghien Lagoon is rich in biodegradable organic matter. The principal component analysis (P.C.A) of the data allowed to define three different types of water of the Aghien lagoon influenced by the seasonal variables. On the whole, the waters of the Aghien Lagoon could be used for the production of drinking water after treatment.