Monochloramine: Disinfectant Stability in Water
Monochloramine stability helps this biocide to remain stable and effective at the proper concentration in low flow regimes where other biocides fail.
Disinfectant stability in water
Look at the graph on this side…
It shows the effect of pH on the relative concentration of these three molecules:
- Monochloramine is very stable and the predominant species at pH above 7.2
- Important to avoid the formation of di and tri chloramines since they are toxic
pH in drinking water:
- Monochloramine is present 100% in its active form
- Hypochlorous acid is present in a mixture
- Free chlorine loses its biocide activity as the pH increases while it keeps its oxidizing power: high corrosive potential
- Monochloramine leading to high biocidal efficacy and much lower corrosivity
Monochloramine has lower oxidant potential of this disinfection, that means: better Biofilm penetration and kill bacteria inside it.
Monochloramine is a suitable biocide for secondary disinfection where long contact time between the biocide and the bacteria is achieved.
Monochloramine stability helps this biocide remain stable and effective at the proper concentration in low flow regimes (oversized pipes, temporary dead legs, varying flow situations) where other biocides fail.