Influence of ammonium nitrogen on the treatment efficiency of underground water at iron removal stations

Providing the population with high-quality drinking water is one of the main tasks, which has become particularly relevant in connection with the observed deterioration of the general environmental situation and excessive pollution of water supply sources. This challenge is especially relevant for small towns. Underground water is widely used as a source of water supply for settlements, a significant part of which has an excess concentration in several indicators, including iron and ammonium compounds. Such water has a complex composition in terms of its processing when classical methods and schemes do not work. The growth of populated areas, the development of industry and the increasing requirements for water quality from various water users lead to the need to find rational methods of water treatment. It has been established that ammonium nitrogen significantly makes it difficult the decrease the concentration of total iron to a normalizing value of 0.3 mg/L, and it is required to apply high air intensity (210 L/min). Practically only a small part of air oxygen is spent on the oxidation of iron, while even at a ratio of 5:1 in filters with sand loading, the problem of reducing the concentration of ammonium nitrogen to the standard values is not solved. The use of the proposed technological scheme with an aeration column will increase the degree of purification of underground water from iron and total ammonium nitrogen to values of 0.15 and 1.5 mg/L, respectively, as well as reduce the cost of manufacturing the installation and the purification process due to the absence of expensive materials (reagents) and equipment in the scheme.