Impact of anthropogenic activities on the physicochemical quality of Oke- Bola Stream, Oyo State, Nigeria

Abstract

The study aimed to determine the impact of anthropogenic activities on the physicochemical quality of the Oke- Bola Stream, Oyo State, Nigeria. Five (5) composite water samples were collected from five (5) stations of the stream. Temperature and pH were tested in situ, then samples were transported to the chemistry laboratory for further analysis using standard methods. The results showed the highest mean temperature in station A (25.1 ^OC), pH in stations C and E (6.73), total acidity in station B (73.0 mg/L), electrical conductivity (EC) (854 μS/cm), total dissolved solid (TDS), salinity, total alkalinity, chloride ion (Cl^-) and dissolved oxygen (DO) in station C (427, 425, 225, 2600 and 15.4 mg/L) respectively. The EC and TDS across the stations were within the WHO (2011) standards (1000 μS/cm, and <600 mg/L). Temperature in station E (24.6 ^OC), pH in stations A (6.26) and B (6.11), total alkalinity in station C (225 mg/L), salinity and Cl- concentration across the stations and DO in four of the stations (A, B, C and E) are not in compliance with the WHO (2011) standards (25-29^oC, 6.5-8.5, 200, 100, 250 and 13-14 mg/L respectively). Pearson correlation revealed a significantly strong association between pH and T. alkalinity (r=0.915). TDS with EC (r= 0.988) and salinity (r=0.992). EC with salinity (r=0.978). T. acidity with DO (r=0.917) p<0.01. The study revealed an unacceptable level of the studied physicochemical parameters in some and across the stations linking to the anthropogenic activities around the stream.