Investigation on how raw water quality abstracted from Von Bach Dam affects the water treatment process

Abstract

ABSTRACT ___________________________________________________________________________ The Von Bach Dam which is used for water supply for human consumption undergoes water quality changes. These could be a result of natural processes in the water body and the quality of water which is entering the reservoir. Such short term water quality changes are impacted by extreme events like floods, intense rain or seasonal changes. The purpose of the study was to determine how the treatment or chemical dosage is influenced by such water quality changes. This involved a correlation of raw water with chemicals used for treatment and analysed with simple linear regression analysis of Genstat and presented with Microsoft Excel. The results revealed a significant relationship between changes in raw water quality and the specific chemicals used for treatment; manganese and iron are oxidised by potassium permanganate, turbidity is treated using U3000, the results suggest the chemicals are influenced by the changes in raw water quality. As such, the significant difference in water quality changes has a positive correlation on chemicals used for manganese and iron. The results indicated that U3000 dosage was negatively correlated with turbidity. High concentrations of manganese (0.26 mg/l) and turbidity (4.3 NTU) were found in raw water and iron occurred in low concentrations. This implies that more chemicals would be needed to treat water accordingly.