Вода і водоочисні технології. Науково-технічні вісті, № 2(36)

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Перегляд Вода і водоочисні технології. Науково-технічні вісті, № 2(36) за Автор "Dontsova, T. A."

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    Fluoride ions removal efficiency of natural/activated zeolite and bentonite sorbents
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2023) Kurylenko, V. S.; Tolstopalova, N. M.; Obushenko, T. I.; Sanginova, O. V.; Dontsova, T. A.
    Addressing the health concern of fluoride ions contamination in water, that cause such deceases as dental and skeletal fluorosis, requires the development of effective adsorption materials for water treatment. Our research objective was to evaluate the adsorption properties and capacities of zeolite and bentonite, sourced from Ukrainian deposits, and their acid-activated forms in relation to fluoride ions and estimate fitting this data to various adsorption models. Characterization of natural and acid-activated zeolite and bentonite sorbents was performed through X-ray diffraction to determine the phase composition of these substances. Adsorption experiments were carried out at different initial fluoride ions concentrations (3, 5, 10 and 15 mg/l) and pH (3.7; 7.5). Acidification (changing pH from 7.5 to 3.7) increase adsorption capacity of natural zeolite and bentonite more than twice. It was found that natural zeolite removes fluoride ions at the level of 67 % at pH 3.7 and a high dosage of sorbent – 10 g/l and an initial concentration of fluoride ions – 5 mg/l, while its acid-activated form was more effective - the removal of fluoride ions is 86 % at a lower dosage of sorbent – 1 g/l. Similarly, natural bentonite demonstrated a maximum removal efficiency of 45 % at pH 3.7 and a dosage of sorbent – 10 g/l, and its acid-activated form allowed for the removal of fluoride ions of about 83 % at a dosage of sorbent – 2 g/l at the same fluoride ions concentration. It is shown that the Vagelar-Langmuir (VL) isotherm model is the most accurate for describing the process of fluoride ions adsorption by acid-activated forms of natural sorbents, where the R2 values are close to 0.999, indicating monolayer adsorption on homogeneous active centers. The obtained results indicate the greater efficiency of acid-activated forms of natural sorbents and the prospects of their use for the removal of fluoride ions from water.
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    Modification methods to enhance the performance of TiO2 in photocatalysis
    (КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2023) Zhou, Z.; Dontsova, T. A.
    With industrial development and changes in human lifestyle, organic pollution has become an increasingly serious problem, posing a serious threat to the ecological environment and human health. As an emerging advanced oxidation process, titanium dioxide–based photocatalysis has shown unparalleled potential in solving environmental pollution problems due to its stable catalyst properties, mild reaction conditions, environmental friendliness and low cost. However, titanium dioxide is limited in its photocatalytic efficiency by the fact that it can only be excited by ultraviolet light, its carriers are easily compounded and its adsorption capacity is weak. In order to improve the photocatalytic degradation efficiency of organic pollutants, the properties of titanium dioxide can be enhanced by means of modification. This article mainly reviews several major modification methods and research progresses of semiconductor titanium dioxide materials for the degradation performance of organic pollutants in the environment, and focuses on the advantages of the new Metal Organic Frameworks/ titanium dioxide composite system in enhancing the degradation performance of organic pollutants. Finally, the application prospects and key issues of Metal Organic Frameworks/ titanium dioxide materials in photocatalytic treatment of organic pollution problems are presented.