Evaluation of Physicochemical Characteristics of Surface Water from Orashi River, Rivers State, Southern Nigeria

Water samples were collected from four different stations bimonthly from the Orashi River for a period of one year. The samples were collected from the shores of selected communities along the Engenni axis of the river. The samples were treated and analyzed according to standard laboratory and analytical procedures for water physicochemical parameters. The parameters examined were pH, Salinity, chlorides (Cl-), Conductivity, total dissolved solids (TDS), total suspended solids (TSS) turbidity, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrates (NO3-), sulphate (SO42-) and phosphates (PO43-). The results showed that the mean values of the evaluated parameters were; pH (6.91±0.11), salinity (9.79±0.27 mg/L), Cl (6.25±0.25 mg/L), conductivity (29.66±1.20 µS/cm), TDS (17.66±2.08 mg/L), TSS (16.83±1.15 mg/L), turbidity (11.84±1.50 mg/L), temperature (28.16±0.12 oC), DO (5.91±0.18 mg/L), BOD (7.30±0.60 mg/L), COD (9.41±0.70 mg/L), NO3- (3.42±0.27 mg/L), SO42- (1.15±0.56 mg/L) and PO43- (15.65±5.76 mg/L). The results of the different parameters showed that all of them fall within the WHO acceptable limit except turbidity, DO and BOD that were not within the recommended range, then COD and phosphates that were either within or above the recommended values at different instances. Based on the findings of this work, the water may not be particularly suitable for drinking purposes, but can be used for other household functions that do not require consumption and also for irrigation. Keywords: water, physicochemical property, human activity, environment, contamination