Combined disinfectants

Combining disinfectants is done to overcome the disadvantages of the individual disinfectant:

Chloramines / Chlorine Dioxide

Overcomes the nitrifying bacteria, maintains a strong residual throughout the distribution system as the final primary disinfectant. Levels are 0.5 ppm chlorine dioxide dose to the chloramines dose.

Chlorine / Chlorine Dioxide

These two products set-up a recycling loop in that the free chlorine oxidises chlorite to chlorine dioxide and the chlorine dioxide keeps the free chlorine( hypochlorous acid HOCl) from dissociating. The combination of chlorine dioxide and chlorine will have the following benefits:

• Reduces THM and other chlorinated organics.
• Reduce chlorite levels in the final water.
• Reduce the mutagenic properties of the final water.
• Reduce the impact on the environment.
• Improve the efficacy of the final disinfection treatment whilst making this combined disinfectant cost effective comparable to chlorine (gas) alone.

Typically the dosage is 3 parts chlorine dioxide to 2 parts chlorine.

Ozone / Chlorine Dioxide

Ozone produces the quick kill and the chlorine dioxide maintains a residual at lower dosages.