A Comparative Study of Groundwater between Geological Groups of Southern Benue Trough, Nigeria Using Modelling Approach

Abstract

Groundwater studies were carried out between two geological groups to evaluate factors that influences groundwater geochemistry. To achieve this, 30 groundwater samples were collected. Parameters such as pH, Electrical Conductivity (Ec), Total Dissolved Solids (TDS), Total Hardness (TH), and hydrochemical characteristics (Na2+, K+ , Ca2+, Mg2+, HCO3¯, NO3¯, Cl¯, CO23¯, and SO42¯) of groundwater were determined. Findings revealed that the pH value for Asu River Group ranges from 5.3 to 7.5, and that of Eze Aku Group ranges from 4.1 to 7.9. It was observed that areas around the mines had low pH values. Analyzed results that were obtained were interpreted using various hydrogeochemical models. Parson plots reflected that groundwater within the two geological groups fell within Ca˗Mg˗SO4 and Ca˗Mg˗Cl. Results from End˗member plots showed that 96% of groundwater samples analyzed were categorized under carbonate weathering, 4% fell silicate weathering. Gibbs plots revealed that interactions between groundwater and surrounding host rocks are mostly the main processes responsible for chemical characteristics of groundwater, Diamond field plots suggested that groundwater within the study were categorized to be high in Ca + Mg & SO4 + Cl, the plot of Ca2+/(HCO3¯+SO42¯) against Na+/Cl¯ revealed that groundwater was considered to be within the natural state for the two group. The plot of TDS against TH showed that groundwater is classified as soft freshwater. The study revealed there was no significant difference between factors that influence groundwater within the two geological.