Why ClO₂  > Comparison  > ClO₂ vs. Chloramine

ClO₂ vs. Chloramine

Not only prevents nitrate formation, but solves taste and odor issues...

Monochloramine is a weak disinfectant and rarely used in the water treatment plant. It is used primarily as a replacement for free chlorine in the distribution system to prevent the continued formation of TTHM's. Free chlorine in distribution will continue to form TTHM's while weak chloramines do not. Chloramines by virtue of being weaker are also more persistant in distribution and thus can reduce or eliminate additional treatment points in distribution.

However, chloramines are a weak disinfectant and thus provide less protection against bacteria regrowth in distribution. Also, the ammonia content of chloramine provides nutrients to nitrifying bacteria which form nitrites and nitrates, both of which are limited in drinking water by USEPA and international government regulations. Many systems using chloramine address the nitrification problem by periodically overdosing with chlorine, commonly called a "chlorine burn". Such actions generate a large number of customer complaints because of odors.

Chlorine dioxide is more effective at reducing TTHM's because it is frequently used as a pre-treatment in the water plant, prior to the use of chlorine. In many cases chlorine dioxide pre-treatment reduces the TTHM level sufficiently so that chlorine may be used throughout distribution without exceeding the allowable level of TTHM's.

For those systems that use chloramine, ClO₂ provides synergistic benefits. First, the disinfection potential is enhanced by the use of both oxidants. And the chlorite ion by-product from ClO₂ acts to prevent the formation of nitrates in distribution by controlling the growth of nitrifying bacteria. When chloramine is used for distribution, excellent performance overall can be achieved by using ClO₂ as a pre-treatment in the water plant, thus providing a chlorite ion residual to protect distribution against nitrification.