Distribution of Essential Elements in Natural Waters: A Case Study of Nwaniba River, Akwa Ibom State

Abstract

Knowledge of the distribution of key elements in natural waters is a crucial variable in evaluating geochemical processes and optimising environmental conditions. This work assessed the Nwaniba River in Akwa Ibom State to calculate the spatial distribution, contamination status of selected essential elements, and the sources of these elements in the sediment and water (Fe, Mn, Cu, Zn, Na, Mg, K, and Ca). It aimed to learn about the interaction between sediment and water, as well as the parameters that determine the behaviour of these elements. Four strategic locations were sampled and analysed using Atomic Absorption Spectrophotometry (AAS). Descriptive statistics, correlation data, geoaccumulation factor (EF), principal component analysis (PCA), and water quality indices (HPI, MI) were used to interpret data. The findings indicated that the realm of the levels of the elements concentration included Fe (76,838 mg/kg in sediment; 3.12 mg/L in water), which is highly exceeded the WHO (0.3 mg/L) ranges. Geogenic control of factors by weathering of minerals indicated strong (r > 0.8) Na--Mg--Ca--Fe correlations, and geogenic control of factors indicated by natural lithologic factors as the major source factor was shown by PCA (PC1 = 72.7% variance). The representative values of the unpolluted sediment, slightly enriched by small anthropogenic contributions (Igeo = 0.4), were used, with EF (<2) and Igeo (<1), resulting in a lower Zn content in the sediment. High WQI (>400) and HPI (>450) proved that the blame for poor water quality lies not with industrial discharge, but with Fe alone. This research paper finds that the Nwaniba River is geologically stable and unchanging and recommends periodic Fe studies of the river as a means of determining the water quality, along the lines of an aerator-based treatment method. It will require the management of the river catchment to maintain the ecological integrity of the River Nwaniba, thereby upholding safe domestic water use. In conclusion, these results can be triangulated with previous studies in the Niger Delta and West African basins to demonstrate that the Nwaniba River is a stable and unpolluted chemical and environmental system, with the degradation of water quality being restricted to the solubility of Fe under natural geochemical conditions.