When ammonia (NH3) is dissolved in water, some of the ammonia molecules will gain a hydrogen ion and this positively charged species is called ammonium (NH4+). The ratio of NH3 to NH4+ is dependent on the pH and temperature of the water. The lower the pH and the warmer the water; the higher the concentration of ammonium due to the increase of H+ ions.

Ammonia at low concentrations is mostly harmless to humans, however, it is an irritant to the eyes and nose. The taste and odour of the water can be affected by the presence of ammonia.

Ammonia is toxic to aquatic life and has been reportedly toxic at levels as low as 0.5 mg/L. High ammonia levels in natural waters can result in an excess of algae growth, which prevents sunlight from reaching the aquatic life and plants eventually causing death.

Ammonia in Drinking Water

In drinking water, ammonia needs to be monitored to safeguard human health. It may be present after disinfection using monochloramines, or because of leaching from materials used in the pipework construction. Chlorine is known to react with ammonia and therefore decreased disinfection efficiency can be expected if the drinking water contains more than 0.2 mg/L of ammonia.

Ammonia in Wastewater

In wastewater, ammonia can reach high levels due to bacterial action. Monitoring of ammonia in wastewater plants is crucial before the effluent is released to prevent the damage to the local aquatic life. Palintest offers a variety of methods for testing ammonia.