Ammonia (NH3) and ammonium (NH4) are present in a combination that depends on the pH of the water. In acidic water (pH< 6,5), only the ionised NH4 form is present. From pH 12, the NH3 form is dissolved as a gas. The maximum permitted value for drinking water is 0,5 ppm NH3. The stated concentration is always the sum of NH3 and NH4 at the given pH. Sometimes both are given as ammonia nitrogen. Conversion to NH3: ppm NH3-N x 1,21. Ammonia comes from biological degradation processes and is common in biological contamination. Ammonia gives water an unpleasant taste.
Ammonia removal:
Ammonia is removed from water by adsorption, air stripping and dosing of strong oxidants. Where necessary, other parameters must also be taken into account and the whole water treatment process monitored.
Adsorption and air stripping apply to the gaseous fraction. As this part is removed from the mixture, more ammonium is converted into ammonia and removed in turn. This process therefore takes time, and the system must allow sufficient reaction time. A practical guideline is 6-8 minutes. The pH is preferably raised to 8-8,5. Possible limescale deposits must be considered if the water is hard. For adsorption, the use of Crystal Right 100 is recommended. An important factor is that it also works as an ion exchanger, so apart from adsorption the medium must have enough capacity not to become saturated with hardness. More information can be found in the Crystal Right product leaflet. Removal by dosing is done by proportional dosing of sodium hypochlorite up to 0,25 ppm residual chlorine. A reaction tank is also recommended (6 minutes). If necessary, the chlorine doses must be increased and an activated carbon filter installed after the reaction tank to reduce the residual chlorine.
Crystal-Right is a zeolite that can remove iron, manganese and small amounts of H2S. It also adsorbs ammonium and raises the pH. Crystal-Right can also filter organic contaminants and capture insoluble inorganic substances.
These "zeolite" crystals come from a sodium aluminosilicate, carefully produced and processed by Mineral-Right using exclusive technology. Thanks to its unique crystalline structure, Crystal-Right™ removes hardness, iron and manganese while also raising the pH of acidic water.
Unlike round resin beads, Crystal-Right™ crystals provide better filtration and are regenerated more effectively by backwashing than ordinary resins, with no loss of product.
Crystal-Right’s White (CR-100) Zeolite is the most durable of the manufactured minerals. White Zeolite raises the pH of acidic water while reducing hardness, iron, manganese and ammonium. Low-pH water tends to be more corrosive than water with a neutral or higher pH. This pH adjustment and reduction of unwanted minerals is sustained by its excellent filtration and backwash properties.
Crystal-Right’s CR150 Zeolite raises the pH of slightly acidic water while reducing hardness, iron and manganese. This pH adjustment and reduction of unwanted minerals is sustained by its excellent filtration and backwash properties.
Crystal-Right's Blue (CR-200) Zeolite is a fine, high-capacity mineral used to reduce hardness, iron and manganese in water. The mineral has a crystalline structure, manufactured to strict specifications and quality control (filter analysis). This extra effort ensures the zeolite has a high softening capacity. In addition to this high capacity, consistently superior performance is possible thanks to its excellent filtration and backwash characteristics.
