3. Chloramines

Figure 17 (§ ) shows that, stopping at the first ascending branch (AB) of the break-point curve, the residual chlorine was combined chlorine, essentially in the form of monochloramine in neutral or alkaline waters. Despite having a much lower oxidizing and disinfecting power than free chlorine, this treatment can be used for some applications, in ERU disinfection or even sometimes in drinking water, as it forms very few by-products such as THMs.

In a complete surface water treatment plant, it is generally preferable to carry out pre-ozonation and eliminate...