Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
Odjadjare, E.E.O., Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa; Okoh, A.I., Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa
The physicochemical qualities of the final effluents of an urban wastewater treatment plant in South Africa were assessed between August 2007 and July 2008 as well as their impact on the receiving watershed. The pH values across all sampling points ranged between 6.8 and 8.3, while the temperature varied from 18°C to 25°C. Electrical conductivity (EC) of the samples was in the range of 29-1,015 μS/cm, and turbidity varied between 2.7 and 35 NTU. Salinity and total dissolved solids (TDS) varied from 0.36 to 35 psu and 16 to 470 mg/L, respectively. The concentrations of the other physicochemical parameters are as follows: chemical oxygen demand (COD, 48-1,180 mg/L); dissolved oxygen (DO, 3.9-6.6 mg/L); nitrate (0.32-6.5 mg NO-{3}^{-} as N/L); nitrite (0.06-2.4 mg NO -{2}^{-} as N/L); and phosphate (0.29-0.54 mg PO -{4}^{3-} as P/L). pH, temperature, EC, turbidity, TDS, DO, and nitrate varied significantly with season and sampling point (P<0.05 and P<0.01, respectively), while salinity varied significantly with sampling point (P<0.01) and COD and nitrite varied significantly with season (P<0.05). Although the treated effluent fell within the recommended water quality standard for pH temperature, TDS, nitrate and nitrite, it fell short of stipulated standards for other parameters. The result generally showed a negative impact of the discharged effluent on the receiving watershed and calls for a regular and consistent monitoring program by the relevant authorities to ensure best practices with regard to treatment and discharge of wastewater into the receiving aquatic milieu in South Africa. © 2009 Springer Science+Business Media B.V.
Best-practices; Discharged effluents; Electrical conductivity; Final effluents; Monitoring programs; Municipal wastewaters; Negative impacts; pH value; Physico-chemical quality; Physicochemical parameters; Receiving watershed; Sampling points; South Africa; Total dissolved solids; Treated effluent; Urban wastewater treatment plants; Wastewater effluent; Water quality standard; Chemical oxygen demand; Dissolved oxygen; Effluent treatment; Electric conductivity of solids; Landforms; Salinity measurement; Turbidity; Wastewater; Wastewater treatment; Water pollution; Water quality; Water treatment plants; Watersheds; Effluents; dissolved oxygen; nitrate; nitrite; phosphate; effluent; environmental impact; physicochemical property; urban area; waste treatment; wastewater; water treatment; watershed; aquatic environment; article; chemical oxygen demand; controlled study; electric conductivity; environmental impact; environmental monitoring; pH; physical chemistry; salinity; seasonal variation; sewage effluent; South Africa; standard; total dissolved solids; turbidity; urban area; waste water treatment plant; water quality; water sampling; water temperature; watershed; Biological Oxygen Demand Analysis; Environment; Fresh Water; Hydrogen-Ion Concentration; Nitrates; Nitrites; Seasons; Temperature; Waste Disposal, Fluid; Water Pollutants, Chemical; Water Pollution, Chemical; South Africa