Abstract: This study is aimed at assessing the hydro-geochemical signature of groundwater in Okpoko and surroundings in Anambra, Southeast Nigeria. Fifteen groundwater samples were collected and analyzed by physicochemical, heavy metals and hydrocarbon content. Heavy metals in groundwater were analyzed using an atomic absorption spectrometer. Groundwater analyzes showed that the average pH (6.05), Fe (0.68 mg/L) and Ni (0.028 mg/L) values are exceeded by the WHO and NSDWQ guidelines. Total petroleum hydrocarbons (TPH) in groundwater were relatively low and recorded only in BH1 (0.04 mg/L) and BH2 (0.002 mg/L) and below the detection limit for all other selected wells. Piper diagrams showed two hydrochemical facies: 3mg-HCO and Ca-HCO3-rich water, while the rigid regimens were confirmed by four separate water types (Ca2+, mg2+, 3HCO; CA2+, 3HCO; CA2+, Na+++; K Cl-, HCO3; CA2+, Cl- class). Gibbs diagrams showed that chemical weathering of rocks and sediments, the main factors affecting the quality of groundwater. Different ionic ratios: mg/Ca (0.56), HCO3/Cl (3.31), (Na+ K)/Cl (1.45), Na/K (1.61), Ca/Na (7.0)/Cl (0.67) and CEV (-0.45) suggests groundwater sources are of internal origin. The direction of the groundwater flow indicates that the areas are drained along the Niger River in the western part of the study area.
Published Date: 04 Jun 2018