EFFECT OF OZONE ON DISINFECTION BY-PRODUCT FORMATION OF ALGAE

The presence of algae in a drinking water source can have a significan t impact on the treatment of that water. Algae and their extracellular organic matter can be precursors for disinfection by-product (DBP) fo rmation which is of concern for treatment plants that employ pre-chlor ination. This research examined the DBP formation of suspensions of Sc enedesmus quadricauda, a green alga, and the effect of ozonation on th at formation. Trihalomethane formation potential (THMFP) was found to increase by 10% to 30% when preozonation was applied versus non-ozonat ed samples. A slight increase in haloacetic acid (HAA) formation was a lso observed in the ozonated samples. Ozonation caused an increase in the dissolved organic carbon content of the algal suspension, thereby increasing the concentration of precursors. The alkalinity of the wate r did not significantly affect the formation potential of either THMs or HAAs. (C) 1998 IAWQ. Published by Elsevier Science Ltd.