Interpretation of hydrochemical data using various geochemical models: a case study of Enyigba mining district of Abakaliki, Ebonyi State, SE Nigeria

The assessment of groundwater geochemistry and characterization is an important aspect of groundwater studies. For this study, a total of 20 groundwater samples were collected from hand-dug well and analyzed using the America Public Health Association standard (APHA) method. Result obtained from the study revealed that Ec, pH, and TDS range from 78.2 to 850 µS/cm, 3.34 to 7.09 and 0.8 to 71.58 mg/L, respectively. From geochemical model, it was observed that findings from End-member plots showed that silicate and carbonate weathering is the major process that influences groundwater. While plot of Ca²⁺/(HCO₃⁻ + SO₄²⁻) versus Na⁺/Cl⁻ revealed that 92% of groundwater within the area falls within the natural state. The plot of Mg/ca against Mg/Na and Parson plot revealed that 73% of groundwater is influenced by rock–water interaction. Further findings from Diamond field plots showed that groundwater fell within High Ca + Mg and SO₄ + Cl, 98% of groundwater fell within Ca–Mg–Cl water type, respectively. The plot of TDS against TH revealed that groundwater fell within soft-fresh and moderate–hard category, Chadba’s plot revealed that groundwater was classified to be of Na⁺  + HCO₃⁻ water type. Gibbs plot and Soltan classification revealed that larger percentage of groundwater is not influenced by the three major factors in Gibbs plots, groundwater within the study area is of deep meteoric type respectively. Findings obtained from ion exchange revealed that groundwater is influenced by mostly silicate weathering. The evaluation of groundwater seepage in heavy metals loads against pH revealed that heavy metals were classified under acid, high-metal, near-neutral high-metal, acid low metal, and near-neutral low metal. Results obtained from the study revealed that groundwater within the study area is influenced by geogenic and anthropogenic activities.