Assessment of Physicochemical Properties of Groundwater Sources from Some Selected Areas in Sokoto Metropolis, Nigeria

The study investigates total of eight groundwater samples, two of the samples A and B are bicentenary dug wells, while others C, D, E, F, G and H are boreholes of between two to ten years old, all located in Sokoto metropolis. After the digestion of the samples with nitric acid, four heavy metals (Cd, Cu, Cr and Pb) were analyzed using Atomic Absorption Spectrometer (AAS). The results from the AAS revealed that 87.5%, 25%, 75% and 87.5% of the samples contained higher levels of Cd, Cu, Cr and Pb respectively than the prescribed limits set by WHO. The results also indicated that the TDS, TSS, Cl^-,NO₃^- and pH of all the samples were within the allowable permissible concentrations and pH range respectively set by WHO. About 62.5% of the samples contained DO slightly below the acceptable limits set by WHO, while 12.5% of the samples recorded BOD₅ values above the WHO permissible levels and the CO₃^- concentrations in all the samples were below the detection limits.