Aldehydes formation during water disinfection by ozonation and chlorination process

The goal of this paper is an investigation into the influence of disinfection with ozone, chlorine (Cl2) and chlorine dioxide (ClO2) on the aldehydes formation. Three types of waters were treated with different doses of these disinfectants. The results obtained indicate that the level of carbonyls concentration can significantly increase with the time of Cl2 and ClO2 reaction with aldehyde precursors in treated water. There is no noticeable correlation between quantity of aldehydes and total organic carbon (TOC) value of disinfected water, but potential of organic by-products formation is evidently connected with the nature of organic material. The range of productivity of aldehydes in water treated with ClO2 or Cl2 is very similar. The productivities of aldehydes were calculated for all investigated waters treated with different doses of oxidant and were 2 – 10 μg of
aldehydes per 1 mg TOC. Formaldehyde and acetaldehyde were the dominant carbonyl compounds identified in water before as well as after the reaction with disinfectants.