Table 1: Various types of chloramines and their properties

Appearance	Name	Molecular Weight	Preferred pH Value	Biocidal Effect
NH2Cl	Monochloramine	52	> 7	good
NHCl2	Dichloramine	85	4 - 7	tolerable
NCl3	Trichloramine	119	1 - 3	average
RNHCl	Organic Chloramines	varies	unknown	bad

What are the applications of chloramines?

Chloramines can be used as bleach, disinfectants and oxidators. Organic disinfectants slowly give off chlorine, causing a slower and less aggressive disinfection than when disinfecting with hypochlorite. Chloramines can be used to improve odor and taste of the water when chlorine is used as a disinfectant. Chloramines are also used for the disinfection of drinking water and wastewater and to resist biofouling in cooling water systems.

Water disinfection with chloramines

When chloramines are used as a disinfectant, ammonia is added to chlorine treated water. Ammonia is added after chlorine, because this causes CT (cycle threshold) values to be lower than when ammonia is added primarily.
Chloramines are as effective as chlorine for the deactivation of bacteria and other microorganisms, however the reaction mechanism is slower. Chloramines, like chlorine, are oxidators. Chloramines can kill bacteria by penetration of the cell wall and blockage of the metabolism. Monochloramine is the most effective disinfectant. It reacts directly with amino acids in the bacterial DNA. During deactivation of microorganisms chloramines destroy the shell which protects a virus. When the pH value is 7 or higher, monochloramine is the most abundant chloramine. The pH value does not interfere with the effectiveness of chloramines.

Is my drinking water disinfected using chloramines?

Chloramines are applied more and more often in Canada as an alternative for chlorine during secondary disinfection of drinking water. For a list of Canadian municipalities that use chloramines, refer to Water FAQ's.
The main reason for the move from chlorine to chloramines is that chloramines react with organic matter less often than chlorine.
Little to no trihalomethanes (THM) and other disinfection byproducts are formed during chloramine disinfection.
Chloramines will remain active within the plumbing much longer. This is because it takes a long time for chloramines to be broken down.
Chloramines do not give off any taste or smell and are relatively safe.

Can chloramines be removed from water?

Chloramines remain active in the water system for a considerably long period of time than free chlorine. Like other molecules, chloramines contribute to the total amount of dissolved solids in the water. Like chlorine, chloramines are selectively reactive and may have damaging affects when they remain in the water for too long.
When chloramines are present, there are usually trace amounts of ammonia and hypochlorite in the water as well. Chloramines are hardly ionic. As a result, and because of the low molecular weight, chloramines, mainly monochloramine, are difficult to remove from water by reverse osmosis (RO) or water softening. Boiling and distillation cannot be used either. Substances for chlorine removal cannot be used for the removal of chloramines. Sunlight and aeration may aid chloramine removal to a certain extent.
Chloramines can be removed by means of an active carbon filter. This filter brings down chloramine concentrations from 1-2 ppm to less than 0.1 ppm. One must make sure that the active carbon comes in contact with chloramines for a significant amount of time. Our drinking water filter, AQ-4000, because it's designed to only filter 2 litres/min, provides enough contact time with the active carbon for chloramines to be removed. In our shower filter, AQ-4100, because of the higher output and, therefore, shorter contact time, we use a special type of carbon, called catalytic carbon, or Centaur carbon.

NOTE: Granulated catalytic carbon has a higher tendency to clog up the filter cartridge, resulting in lower water pressure. If you already have a low water pressure in your bathroom, you may want to select our regular coconut shell carbon / KDF-55 shower filter instead.

The amount of chloramines in the water can be determined by measuring the 'total chlorine' residue. This means measuring the 'total amount of chlorine' or the 'amount of chlorine compounds'.

What benefits and drawbacks are there to using chloramines?

Benefits

Few disinfection byproducts
Using chloramines benefits over using chlorine, because few organic compounds (trihalomethanes; THM) and other possibly carcinogenic byproducts (halogenic acetic acid; HAA) are formed.

Chloramines remain active for a long time
Chloramines remain in the water longer than chlorine. Monochloramines are most effective when the pH value is 7 or higher. When the pH value exceeds 7 the water is alkaline. The benefit of alkaline water is that it is less corrosive than acid water. When the pH value is high chlorine can be found in the water as hypochlorite ions (OCl^-). These ions have a higher oxidation potential than underchloric acid. However, as a disinfectant it is a hundred times less effective than underchloric acid. When pH values are too high, its affectivity will diminish.

Chloramines and the taste and smell of the water
Chloramines improve the taste and smell of your water (water doesn't smell of chlorine).

Drawbacks

Formation of organic chloramines
When large amounts of organic matter are present in the water, organic nitrogen causes the formation of organic chloramines. These do not possess the same disinfection properties as inorganic chloramines. This situation occurs when organic matter contents exceed the 3 ppm boundary.