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 (Fe-2(SO4)(3)) as coagulant and either chlorine (Cl-2) or chlorine dioxide (ClO2) as the disinfectants. FeCl3 was a better coagulant compared to Fe-2(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 Cl-2 resulted in the highest turbidity and UV254 removal, 97.11% and 79%, respectively, while the combination between Fe-2(SO4)(3) and Cl-2 only recorded DOC removal of 25.5% from the water sample.