Перегляд за Автор "Klymenko, N."

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    Cycles of solar activity as a basis for forecasting the quality of Dnieper water
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Kulishenko, O.; Klymenko, N.
    One of the main features of the quality of the Dnieper water is the content of natural organic substances which determine the water oxidizability and color indexes. A special problem is that organic substances are poorly removed by water treatment plants. A significant problem in the operation of water treatment plants is the unpredictability of annual changes in the quality of Dnieper water, which complicates logistics management, for example, the supply of reagents. Many years of experience related to the Dnieper water supply station in Kyiv (DnWS) have led to the hypothesis that these changes are in some way related to the cycles of solar activity. The purpose of this work is to test this hypothesis to substantiate the possibility of predicting the quality of Dnieper water depending on the action of such a global factor as solar activity. The work was performed by statistical methods using 60-year results of Dnieper water analyzes provided by the DnWS laboratory, as well as Wolf numbers (Sunspot Numbers) provided for free use by the Royal Observatory of Belgium. The influence of solar activity on the quality indicators of Dnieper water, especially in its peak and post-peak periods, has been statistically confirmed. The interaction of biological and physicochemical parameters as factors influencing water quality is shown. As a result of the construction of six reservoirs in 1931-1976, the Dnieper from the river actually turned into a network of water bodies. Now these reservoirs are a kind of reactors in which water is treated by electromagnetic solar radiation, which leads to the cyclic transformation of phytoplankton and natural organic matter. Taking into account the cycles of solar activity, the logistical planning of the operation of water treatment facilities receives an independent "base", changes in which can be predicted with some reliability for years to come.
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    Rational conditions of producing the activated carbon with well-developed nanoporous structure for the treatment of natural and waste waters
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2023) Klymenko, N.; Savchyna, L.; Kosogina, I.; Vrubel, T.
    Rational conditions for the activation of coal of a high stage of metamorphism (anthracite) have been determined, which allow the development of a nanoporous structure. Obtained activate carbon with nanoporous structure can be use for the treatment of natural and waste waters have been carried out. The structurally sorptive characteristics and granulometric size composition of obtained samples were determined. It was established that in order to obtain a sorbent with specified properties, it is necessary to introduce oxygen into the reacting mixture at the second stage of anthracite activation and control the activation time. The activation in the first stage was carried out with steam at a temperature of 750–800 °C, and in the second stage – with steam in the presence of air oxygen at 280–300 °C. The rational content of oxygen in the activating mixture is in the range of 2.7–4.4 %, while the specific surface area of activated carbon increases, which corresponds to nano-sized pores and, accordingly, the volume of the adsorption space of coal. The process led to the development of mesoporosity ~ 0.2–0.3 cm3 /g, after which the microporous sample of activated carbon was impregnated with a surfactant solution. Thus, the rational conditions of activation are the duration of the process of 1.5 hours in the presence of 4.4 % oxygen in the activating mixture. It is shown that the largest values of the total specific surface area and the specific surface area of mesopores are achieved when using ionic surfactants with alkyl chain length n = 10–16 as modifiers. In particular, the use of sodium dodecyl sulfate СН3(СН2)11SO3Na as a modifier allows to obtain the largest value of the total surface Stot 1030 m2 /g and the surface of mesopores Smе 334 m2 /g. It was established that the activation of modified samples of activated carbon leads to a decrease in the size of granules.The content of fractions with a size of 1.0–2.0 mm and 0.5–1.0 mm is 80–85 %, which are rational for use for water purification from organic compounds.