Physicochemical Characteristics of Water Samples Collected from River Sokoto, Northwestern Nigeria
Atmospheric and Climate Sciences
Physicochemical parameters of surface water collected from six different points (P1 to P6) on River Sokoto were analysed during January (Dry Season) and August (Rainy Season), 2014 to determine its water quality using standard methods. The highest temperature of 25.6˚C was recorded by P1 in dry season while P5 recorded the highest value of 29.2˚C in rainy season. All the water samples were alkaline in dry season with the highest pH value of 8.50 in P5 and the least value of 8.02 in P6 whereas
... .02 in P6 whereas in rainy season, P1, P2 and P3 were slightly acidic while P5 and P6 were slightly neutral and P4 alkaline. The highest values of 510 µS/cm and 850.3 mg/l were recorded from P4 for electrical conductance and hardness respectively in the rainy season whereas in dry season, P5 and P4 had the highest values of 321 µS/cm and 282.8 mg/l respectively. The highest DO and BOD levels in dry season were 1.7 mg/l and 0.7 mg/l respectively in P1 and the least values were 0.7 mg/l and 0.2 mg/l respectively in P5. But in the rainy season, P6 recorded the highest DO value of 0.1 mg/l while P2 and P5 recorded the least value of 0.07 mg/l. For BOD, P5 had the highest value (2.13 mg/l) while P3 had the least value (0.20 mg/l). For COD, the highest value (230 mg/l) was found in P4 and P6 and the least value (30 mg/l) was found in P1 in dry season while in the rainy season, P2 had the highest COD value (1008 mg/l) and P4 had the least value of 32 mg/l. TDS and TSS values generally were higher in the rainy season than in the dry season due to higher amount of floating particles in the rainy season. While P1 and P6 recorded the highest values (800 mg/l and 700 mg/l respectively) in the rainy season, P4 recorded the least value of 100 mg/l in both seasons. The highest Chloride level was found in P4 in the dry (100 mg/l) and rainy (180 mg/l) seasons with the least level in P2 (35 mg/l) in dry season and in P1 and P2 with the least level of 60 mg/l in the rainy season. The highest concentration of Sulphate in P1 (220 mg/l) in dry * Corresponding author. M. I. O. Raji et al. 195 season was far above the highest concentration (124 mg/l) in the rainy season whereas highest concentration of Nitrate in dry season in P1 (19.7 mg/l) was somehow below the highest concentration in rainy season in P4 (28.1 mg/l). Phosphate and Ammonia had the highest values of 1.77 mg/l and 0.84 mg/l respectively in P5 in dry season while in rainy season, P6 and P4 had the highest values of 0.22 mg/l and 1.20 mg/l respectively. There was significant seasonal variation in some physicochemical parameters and most of the parameters were within permissible limits, thus, making the water suitable for irrigation purposes.