the effects of water ozonation on disinfection by-product formation

background : the aim of this study was to evaluate the performance of water ozonation on disinfection by-product formation. methods : experiments were carried out on samples taken from tajan river, mazandaran province, iran. samples of the pre-filtered raw water and from the 3.5-l water tank reservoir (wt) were analyzed for uv-254 absorbance, dissolved organic carbon (doc), hs and non-hs, chlorine residual, simulated distributed system total trihalomethanes (sds tthms) and sds halo acetic acids (sds haas). the gaseous ozone concentration was varied between 1.5 and 10 g/m 3 . results : the study showed that use of the ozonation treatment system resulted in significant improvement in water quality compared to the filtered raw water and the levels of doc,  moreover uv absorbing compounds, sds tthms and sds haas were reduced. conclusions: ozonation treatment system can be used instead of other disinfection systems such as chlorination which have potential of disinfection by-products (dbps) formation.