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.