Hydrochemical characteristics and groundwater quality evaluation of roni area, northwestern nigeria

Abstract

Rapid population growth rate in the study area results to an increasing demand of water for various uses. It necessitated the geoscientists to evaluate the water quality of the area for potability. Twenty (20) water samples were collected using plastic bottles and properly labelled. Atomic Absorption Spectrometry (AAS) and X-Ray Fluorescence (XRF) were used to analyse the water quality. The in-situ measured parameters of water are mostly within limit of NIS, 2007 and WHO, 2011. Cations and anions analyses revealed, they were within the range of acceptable standard, except higher concentration of Fe2+, Pb2+and Mn2+which might have resulted from acidic water of the area and weathering of silicate minerals. The cations preponderance is of the order Na+> K+ ˃Mg2+> Ca2+> while for the anions dominance are HCO3− > Cl- > SO4 2- . The dominant water facies are Na+-HCO3−. These facies might have sources from rock-water interaction of silicate minerals. Wilcox plot of salinity hazard of the water samples indicated that, the water of the area is good for irrigation. It can be classified, the value of electrical conductivity of 0 – 250 excellent, 250 – 750 good, 750 – 2250 doubtful and ˃ 2250 µS/cm unsuitable. Field study and petrographic analysis revealed that, the area is underlain by three (3) major rocks units which are muscovite schist, porphyritic granite, sandstone (Chad Formation) with quartzite occurring as the minor lithology.