Ammonia or ammonium is typical in groundwater. Under the current drinking water quality regulation must not exceed 0.5 mg/l in water. If it is higher than this, it must be removed or reduced below the limit value. Ammonia itself actualy has no physiological effect, as in many mineral waters ammonia found above the drinking water regulation, wich is officially allowed. The only reason that ammonia in drinking water cannot be high is that the microbiological purity of water network cannot be guaranteed, so the bacterias can react with ammonia to cause nitrification. The first step in the nitrification process is the formation of nitrite, wich is already toxic.
When we talk about ammonia removal, we are literaly talking about the complete removal of ammonia and not its reduction. This is because any ammonia removal equipment, wether biological, absorption, or oxidation technology is used, only water treatment and purification technology works properly, after no or very low ammonia can be measured. The semi ammonia discharge is a result of a faulty water treatment plant, even if the amount of ammonia after the water treatment is below the specified in the current drinking water regulation.
Ammonia removal can be performed in several ways, with several water purification technologies:
biological ammonia removal:
This is the oldest method of removing ammonia. In this case, we perform the nitrification with the help of certain microbes and bacteria. The ammonia is removed using enzymes produced by bacteria in two steps. The first step is the conversion of ammonium to nitrite and the second is the conversion of nitritet o nitrate. Several charges can be used to ”colonize” bacteria. For example, a gravel filter, an active carbon filter, or a Zeolite charge. The technology used must always taken cara the filtration rate, the oxygen content of the water, the water and ambient temperature. The disadvantage of this system is a relatively large amount of space is required and the conditions must be designed tot he bacteria can be maintained. After a biological water treatment plant, you have to deal with disinfecting the water, wich can be done with chemicals, ozone, or even UV equipment.This water treatment method that maybe the most expensive, maybe the most ”macerate”, but the most gentle to water. This ammonia removal treatment technology is only recommended for large systems with more than 100 m3/h.
chemical oxidation ammonia removal:
This is the simplest and most common technology for ammonia removal. For many years, the oxidation of ammonia has been performed with active chlorine (chlorine gas or a liquid-based chemical), but hydrogen peroxide oxidation has also become widespread. The difference between two chemicals, while trihalomethanes are formed after chlorine oxidation, after hydrogen peroxide not. trihalomethanes are a very potent toxic and carcinogen compound, so an active carbon filter have to be used to filter it out after chlorine oxidation.In the case of chlorine oxidation, it should also be noted, if the ammonia content of the water is too high (above 3-4 mg/l), the residual chloride content of the used chlorine may be present above the limit value in the already ammonia -treated water. If this hazard exists due tot he high ammonia content, it is recommended to uese another technology.
absorption ammonia removal:
This water treatment and water purification technology is originate from a very old method. A well-proven household deodorant, cat litter is nothing more than an artificial material or natural rock that can bind ammonia very well. This absorption process has been used in the last 10 years as a water purifier in water treatment and is now being used more and more places for ammonia removal. The charge used in the absorption process (wich can be a natural Zeolite or an artificial material) is sooner or later saturated with ammonia, it must be regenerated in order to be able to absorb again. This regeneration process is almost the same as the regeneration of the softener, it is done with salt (sodium chloride), in some types of charges with an additional chemical, alkali. The only disadvantage of this water purifier is the absorption charge has a very good water softening attribute, so after the water treatment and water purification equipmen we will have not only ammonia free but also soft water, wich is not always advantageous or permissible.