Physicochemical properties of wastewater effluent from two selected wastewater treatment plants (Cape Town) for water quality improvement

Abstract

Effluent from wastewater treatment plants (WWTPs) is one of the main sources of pollution that seriously affect the physicochemical parameters in water bodies. This occurs particularly when partially treated or untreated effluent is released to various aquatic ecosystems. This constitutes a potential danger to the general environment. To safeguard the lives of human, aquatic and other living organisms, regular monitoring of wastewater effluent to ascertain their compliance with both national and international regulatory limits for water quality improvement is very crucial. This research work was carried out using standard methods to evaluate ten physicochemical parameters from the effluent of two WWTPs in Cape Town, South Africa. Our findings were: temperatures (16.90–25.33 °C), pH (5.85–7.85), EC (923.00–1294.17 µS/cm), TDS (590.72–828.27 mg/L), DO (1.30–5.50 mg/L), SO42− (3.23–163.18 mg/L), COD (23.70–898.58 mg/L), BOD (9.17–252.44 mg/L), Cl− (48.17–378.48 mg/L) and PO43− (0.10–11.32 mg/L). Temperature, pH and SO42− levels in the two WWTPs were within the recommended limit for wastewater discharge by the Department of Water Affairs and Forestry (DWAF), South Africa and the United State Environmental Protection Agency (USEPA). However, other parameters did not comply fully with both DWAF and USEPA standards. The result showed that effluents from these WWTPs are possible sources of pollution to the receiving water bodies and calls for enhancement of the WWTPs operations to ensure safe effluent discharge.