Assessment of the Suitability of the N’ZI River Water (Côte d'Ivoire) for Biological and Drinking Water Use

The evaluation of the suitability of N’Zi River water (Côte d’Ivoire) for biological functions, potable use, and livestock watering across the N’ZI watershed provided an integrated basis for evaluating the river’s overall water quality. The objective of this study was to determine the river’s fitness for biological processes and potable water use. To this end, sampling was conducted at five sites with a total of 20 samples collected during the dry season and the rainy season. The characterization of water quality was evaluated based on ten (10) alterations. These include organic and oxidizable matter, nitrogenous matter excluding nitrates, nitrates, phosphorous matter, suspended particles, acidification, temperature, mineralization, color, and mineral micropollutants in raw water. Following the determination of the mean concentrations for the measured parameters, the quality indices of the ten (10) alterations were computed using a framework derived from the Water Quality Index (WQI) concept. This procedure enables the application of the SEQ-Water method to evaluate the suitability of N’ZI River water. The results reveal that water temperature and electrical conductivity reflect a low mineralization of N’ZI River water, corroborated by the observed dissolved oxygen concentrations. In contrast, turbidity and suspended solids (SS) exhibit considerable spatial and temporal variability. Nutrient concentrations including nitrate, nitrite, phosphate, and ammonium remain consistently low relative to international water quality standards, indicating limited anthropogenic nutrient input. The organic composition shows significant variation related to anthropogenic activities. As for heavy metals, they exceed the standard. The metals are of poor to very poor quality. The waters are of good to very good quality regarding nitrogenous matter excluding nitrate, nitrates, mineralization, and mineral micropollutants at all sample collection sites. The classification according to the alteration indicates that the waters of the N’ZI river are generally of good to moderate quality for its suitability for biology, for drinking water use, and very conducive to watering.