Nitrite is a type of acid that is never obtained free but exists in solution. Nitrite passes into the waters with the degradation of proteinaceous substances. The amount of nitrite nitrogen in drinking water should not normally exceed 0.1 milligram per liter.

When nitrite reacts with amines chemically or enzymatically, as in cleaning with chlorine, it forms nitrosamines, which are carcinogenic. Nitrate is present in very small amounts in newly formed domestic wastewater. However, the concentration is very high at the exit of biological treatment plants where nitrification takes place.

Nitrite is formed by the nitrification of ammoniacal compounds in domestic wastewater. All of the methods applied to determine nitrite nitrogen in authorized laboratories are spectrophotometric. These methods are grouped into four main groups:

• Diazotization of aromatic amines and coupling with azo dyes
• Oxidation of organic molecule using nitrite
• Formation of free chromogen radicals
• Formation of nitroso compounds

Nitrate is an important nutrient for many photosynthetic autotrophs. As is known, autotrophs are self-feeding organisms that can produce the food they need to feed on their own. Nitrite, on the other hand, takes part in both the conversion of ammonia nitrogen to nitrate and the intermediate oxidation steps in the reduction of nitrate. These transformations and changes can be seen in wastewater treatment plants, water distribution systems and natural waters.

Sewers, factory wastes, harmful chemicals from pharmaceutical and paper mills, soils drifting as a result of erosion, domestic wastes, pesticides and fertilizers, diesel, tar and burnt oils from sea vehicles, mixing of hot water from power plants to surface waters, water-insoluble detergents and Water is polluted for many reasons. Pollution of water poses a serious threat to living things. Therefore, some limitations are brought by legal regulations and published standards.

 

Therefore, water and wastewater measurements carried out in accredited laboratories are of great importance.