Abstract
The final effluents of two wastewater treatment plants (WWTPs) in the Eastern Cape Province of South Africa were evaluated for their physicochemical and microbiological qualities over a period of 12 months. The physicochemical parameters assessed ranged as follows both plants. The ranges of values for the physicochemical are: pH (3.9-8.6), total dissolved solids (86.50-336.3 mg/L), electrical conductivity (13.57-52.50 mS/m), temperature (13-28 °C), nitrate (0-21.73 mg/L), nitrite (0.01-0.60 mg/L), orthophosphate (1.29-20.57 mg/L), turbidity (4.02-43.20 NTU), free chlorine (0.05-7.18 mg/L), dissolve oxygen (3.91-9.60 mg/L), biochemical oxygen demand (0.1-9.0 mg/L) and chemical oxygen demand (4.67-211 mg/L). The microbiological assessment for both WWTPs revealed the presence of E. coli in counts ranging between 0 and 1.86 × 10⁴ CFU/100 mL and Vibrio counts ranging between 0 and 9.93 × 10³ CFU/100 mL. We conclude that these WWTPs are important point sources of pollution in surface water with potential public health and ecological risks.