Hydrogeochemical Characterization and Quality Assessment of Groundwater Based on Water Quality Index in Imo state, South Eastern Nigeria

Abstract

Water Quality Index (WQI), Principal Component Analysis (PCA), Correlation matrix, Metal Pollution Index (MPI), Contamination Factor (CF), Pollution Load Index (PLI), Geoaccumulation Index (Igeo), Health Risk Assessment, and Hydrogeochemical facies were used to analyze statistical indexes and hydrogeochemical facies in groundwater resources in Imo state, Nigeria. All across the study area, twenty (20) groundwater samples were collected in a systematic manner. The samples were examined in accordance with the American Public Health Association standard (APHA) method. Findings from the study revealed that WQI, is of poor quality and should only be used for irrigation. Weathering and redox reactions are important in groundwater geochemistry, according to PCA results. TDS and Cl, HCO₃ and  Zn, Cl; Mg and Ca, Ca and Na were all found to have a positive correlation in the correlation matrix while PH and K, HCO₃ and Fe, Cl and SO₄ are found to have a negative correlation in the correlation matrix. The findings show that the items have a weak correlation and that there is no relationship between the two variables. Further MPI, CF, and PLI findings revealed that groundwater is pure, the main source of pollution is geological and anthropogenic processes, and there is no pollution in sampled groundwater. Hydrogeochemical trend revealed that groundwater is Na⁺+K⁺ > HCO₃¯+CO3> Mg+ > SO4> Cl¯ > Ca⁺. Based on the finding, pre-use treatment of water resources is strongly advised.