Hydrogeochemical assessment of groundwater quality in parts of the niger delta, Nigeria

Evaluation of major factors influencing the geochemistry of groundwater using graphical and multivariate statistical methods in Yenagoa city, Southern Nigeria

“…They all form a network which empties to the Atlantic Ocean through Nun River Estuary. These rivers are mostly turbid during the wet season possibly due to discharge of clay and silt (Amadi et al 1987). The natural vegetation of the study area is that of the rain forest but this has been destroyed by the activities of man such as bush burning, farming, construction and illegal crude oil refining activities.…”

“…This Formation consists predominantly of unconsolidated pebbles, and very coarse to fine-grained sand units with subordinate shale beds. Underneath the Agbada Formation is the Akata Formation of Eocene to recent age (Amadi et al 1987), which is made up of shales with local inter-bedding of sands and siltstones. It was deposited in a typically marine environment with maximum thickness of about 6,100 m (Ofoegbu 1989).…”

“…These sediments contain inorganic sulphides including pyrite and other ironbearing minerals such as pyroxene, amphiboles, biotite, magnetite and olivine (Amadi et al 1987). Oxygen transported into such layers, either by convection transport or direct exposure to air by lowering of groundwater levels results in oxidation of pyrite.…”

“…Also, the low values of sulphate concentration in the groundwater (Table 1) are attributed to the removal of sulphate from the water by sulphate-reducing bacteria. The reduction of sulphate ions produces hydrogen sulphide; the unpleasant odour of which could easily be detected in the swamps of the Niger Delta (Amadi et al 1987). …”

“…Ruiz et al (1990) suggested that the basic purpose of such an analysis was to study the hydrogeochemistry of aquifers by simplifying the numerous and complex groundwater data into a set of factors, few in number which can explain a large amount of the variance of the analytical data and also indicate the source of origin of various ions present in water. Earlier studies carried out in the study area are on the geochemistry of groundwater (Amadi et al 1987), prospecting of groundwater resources (Okiongbo and Ogobiri 2011), and groundwater quality with respect to drinking and agricultural purposes (Okiongbo and Douglas 2013). These studies mainly focus on chemical composition of groundwater using conventional methods only.…”