The main aim of this study was to determine a treatment strategy for the Berg River water at the Voëlvlei water treatment plant (WTP). Jar tests were conducted using ferric and aluminium sulphate as coagulants to determine the optimum treatment parameters of the Berg River water and the Voëlvlei WTP raw water. The results for the Voëlvlei WTP raw water and the Berg River water with ferric sulphate as the coagulant showed an optimum Fe3+ dosage of 3.0–4.0 mg/L and 4.0–6.0 mg/L, respectively, with an optimum coagulation pH range of 6.6–9.5 and 5.0–10.0, respectively. The results with aluminium sulphate as the coagulant showed an optimum Al3+ dosage of 2.5–3.0 mg/L and 4.0–5.0 mg/L, respectively, with an optimum coagulation pH of 6.0–7.0 and 6.0, respectively. This study concluded that the Berg River water cannot be effectively treated at the Voëlvlei WTP using the plants treatment parameters, even if it is blended with the Voëlvlei WTP raw water. The best treatment strategy for the Berg River water would be pre-treatment using either ferric sulphate or the MIEX® resin on its own, or in conjunction with one another.
Keywords: aluminium sulphate, Berg River water, ferric sulphate, jar tests, treatment strategy, Voëlvlei raw water