Disinfection By-Products Precursors Removal by Simultaneous Coagulation and Disinfection in River Water

Disinfection in drinking water had significantly reduced the risk of pathogenic diseases but may cause chemical threat to human health due to disinfection by-products (DBPs) formation in the presence of natural organic matter (NOM). In general practice, NOM can be removed by using coagulation process. However, the efficiency of a coagulant-disinfectant mixture as a quick water treatment measure in removing NOM as the disinfection by-products needs to be determined. The main objective of this research is to determine the ability of DBPs precursors’ removal of coagulant—disinfectant mixtures. Selected water quality parameters which are turbidity, UV₂₅₄ and DOC were tested to observe the DBPs precursors removal when using either ferric chloride (FeCl₃) or ferric sulphate (Fe₂(SO₄)₃) as coagulant and either chlorine (Cl₂) or chlorine dioxide (ClO₂) as the disinfectants. FeCl₃ was a better coagulant compared to Fe₂(SO₄)₃ in removing DBPs precursors with percentage of 98.03 and 87.91 removal for turbidity, and UV₂₅₄, respectively. The combination between FeCl₃ and Cl₂ resulted in the highest turbidity and UV₂₅₄ removal, 97.11% and 79%, respectively, while the combination between Fe₂(SO₄)₃ and Cl₂ only recorded DOC removal of 25.5% from the water sample.