Purification of natural water from radon

Underground waters of the Ural region, across a large area, have elevated concentration of radionuclides, including that of radon-222. This is explained by the presence of the so-called “granite axis” of the Urals. According to available publications, the excess of this isotope in potable water and in indoor air leads to numerous functional disorders in human body. This paper presents data on the chemical and radiological composition of underground water in a specific area and highlights the field-tested methods of water treatment aimed at reducing the concentration of radon-222. To reduce the content of radioactive isotopes, such methods as sorption, membrane filtration, and aeration have been considered. A comparison of these methods of removing radon-222 from water is performed, and flowcharts of purification are presented. It is shown that each of the methods has both advantages and disadvantages. However, the optimal method for removing small concentrations of radon from water, according to the authors, is the non-pressure aeration. It allows for the low cost of equipment as compared to other methods, and that is important for individual construction, when an owner bears all the financial burden of installing and operating the equipment. This method is also characterized by a high degree of water purification and minimal impact on the environment. The article deals with the issues of protecting the indoor air against the accumulation of radioactive isotopes in it, since this also negatively affects human health.