Вода і водоочисні технології. Науково-технічні вісті, № 1(29)
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Документ Відкритий доступ Elimination of antibiotics by photocatalytic methods(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Kutuzova, Anastasiya; Dontsova, Tetiana; Davydova, MarynaAntibiotics have been found in water bodies of different origin around the world, including natural waters. The presence of antibiotics in natural waters is already an important environmental problem, as they pose a potential threat to the environment. Analysis of the literature shows that photocatalytic methods are considered to be more promising than biological methods and adsorption processes for the treatment of water bodies contaminated with antibiotics and other pharmaceuticals. The aim of this study was to determine the efficiency of antibiotics removal (ciprofloxacin, sulfamethoxazole and trimethoprim) by photocatalytic methods over TiO2 photocatalyst modified with yttrium oxide. For this purpose, a commercial sample of TiO2 P25 (Evonik) was modified, which was further characterized by X-ray diffraction and X-ray fluorescence analysis methods. The obtained data indicate the presence of yttrium in commercial P25 sample after modification. Studies on the removal of antibiotics from aqueous solutions by photocatalytic methods were carried out in three ways: employing modified photocatalyst; combination of photocatalyst and hydrogen peroxide, and the combination of photocatalyst with hydrogen peroxide and ozone. The results of research demonstrate high efficiency of photocatalytic methods in the oxidation of antibiotics in aqueous solutions, among which the greatest oxidation is achieved using the combination of heterogeneous photocatalyst, hydrogen peroxide and ozone.Документ Відкритий доступ Improvement of gas monitoring methods in water of the hydrogen-water cooling system of npp’s turbine generator(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Zaitsev, S. V.; Tykhomyrov, A. Yu.; Chychenin, V. V.; Kyshnevskyi, V. P.The relevance of research is to ensure and improve the reliability of turbine generators (TG) with a hydrogen-water cooling system by monitoring the content of dissolved gases in the water of a hydrogen-water cooling system with monoethanolamine (MEA) – C2H7NO and water vapor in the cooling hydrogen of the turbine. In this work, the influence of ultrasonic vibrations on the decomposition of a mixture of water and turbine oil, organic acids (acetic acid - С2Н4О2, formic acid - СН2О2, oxalic acid - С2Н2О4) or monoethanolamine was determined. The distribution coefficients values were definedd for the following dissolved gases Н2, О2, N2, СО, СН4, С2Н2, С2Н4, С2Н6, С3Н6, С3Н8, which are of degradation products of water mix components when exposed to ultrasonic oscillation in the following system: «dissolved gas – mixture «water + monoethanolamine» – extractant argon (Ar)». The obtained values of the Кі distribution coefficients for dissolved gases in systems «dissolved gas – mixture «water + С2Н7NО» – extractant argon (Ar)» at a temperature of 293 K and a concentration of С2Н7NО at the level of 1 g/dm3 are close to similar values for dissolved gases in deionized water. The principle flow chart of multichannel gas chromatograph for detecting dissolved gases in water and steam of water in hydrogen was developed. Developed flow chart of 4-chennel gas chromatographer for defining dissolved gases in water includes the one gas chromatographer with conductivity detector, methanator, flame ionization detector, argon gas-bearing and supplementary gases of hydrogen and air.Документ Відкритий доступ Adsorption of 4-chlorphenol by brown coal activated by potassium hydroxide(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Таmarkina, Yu. V.; Frolova, I. B.; Кucherenko, V. O.The purpose of the work is to evaluate the 4-chlorophenol (CP) adsorption capacity of brown coal activated carbons (ACs) prepared at different temperature of KOH activation. ACs were obtained in three stages: 1) impregnation of coal with a KOH solution, 2) heating (4 deg/min) in argon to a given temperature t (400-800C) and exposure for 1 h, 3) cooling, washing from KOH, drying. The samples are designated as AC(t). Based on the N2 adsorption-desorption isotherms, the ACs total pore volume (Vt, cm3 /g) and specific surface area (S, m2 /g) were determined. The ACs adsorption capacities were measured at 25С, CP concentration 700 mg/L, АC dosage – 1 g/L. The alkaline activation temperature was found to be a key factor in forming porosity of ACs and ability to adsorb CP. The CP maximum capacity (ACP(m), mg/g) increases 6.6 times up to 307 mg/g for AC(800) having S=1142 m2 /g. The specific adsorption capacity (ACP(S) = ACP(m)/S, mg/m2 ) sharply decreases in a sample range from AC(400) to AC(550) and weakly depends on temperature at 550-800C. The kinetics of CP adsorption is best described by a pseudo-second order model. The rate determining stage is the interaction of CP molecules with AC surface. The CP adsorption isotherms are best described by the Langmuir model. The dependence of the ACP(m) from S can be approximated by three linear equations that probably correspond to the three regions of forming surface adsorbtion centers (AdCs). The first (S370 m2 /g) is characterized by a small adsorption capacity increment (kS=0.103 mg/m2 ), but a significant (16.4 times) decrease in the specific capacity ACP(S). In the second region (S=370-770 m2 /g, t=550-750C), capacity increment is 10 times more (kS=0.985 mg/m2 ) and in the third region (S770 m2 /g, t750C) the increase in CP capacity is the smallest (kS=0.067 mg/m2 ). The thermoinitiated formation of AdCs is assumed to be not proportional to the increase in surface area, and their chemical structure and reactivity is determined by the alkaline activation temperature.Документ Відкритий доступ Preparation and characterization of polyacrylonitrile membranes with antibacterial properties(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Vakuliuk, Polina; Furtat, Iryna; Potvorova, Nadiia; Zabava, Lucia; Sobczuk, HenrykA common problem in separation, fractionation and water treatment is the development of methods for modifying industrial PAN membranes to prevent biological contamination, including the formation of biofilm on the surface of the membrane, and prolong their use. We describe the method of formation of polyacrylonitrile membranes with antibacterial properties by addition into the casting polymer solution of antibacterial polymeric compounds: polyhexamethyleneguanidine chloride, oligourethanesemicarbazide with terminal cationic pyridinium chloride groups, and the polyvinylpyrrolidone-iodine complex. We investigated the effect of the addition of antibacterial compounds to the casting solution on the physicochemical, transport and antibacterial properties of the obtained membranes. We show that increasing the concentration of the bactericidal additives in the casting solution to 3% (wt.) leads to a change in the investigated physicochemical characteristics, water flux and membrane rejection of polyethyleneglycol and low molecular weight electrolyte type 2-1 (CaCl2). We found that membranes prepared from the polymer solution with 3% (wt.) of antimicrobial substances are characterized by high antibacterial activity up to 50 days.Документ Відкритий доступ Flotation method for wastewater treatment from oil products contaminants(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Maksymiuk, Mariia; Kravchuk, Tetiana; Titova, Olha; Kosenko, Olena; Spaska, OlenaIndustrial and natural wastewater is one of factors of the environmental pollution, in particular, its water basin. Among others, fuel and oil pollutants are toxic substances that cause a significant harm to all living things. It is necessary to create technologies using effective methods of wastewater treatment to solve such problems. It is possible to properly select and effectively use methods of treatment taking into account the nature, condition and concentration of contaminants in wastewater. These are the issues addressed in this article. Particular attention is paid to the use of flotation as a method of treatment of stable highly dispersed emulsified wastewater containing oil or fuel contaminants in the technology of this type wastewater treatment. The main objectives of a study were to evaluate the impact of parameters and flotation reagents on an efficiency of the treatment process of stable highly dispersed emulsified wastewater. Flotation of such wastewater was carried out on a laboratory flotation installation of pneumatic type and compared with the process of wastewater settling over time. Studies have shown that for stable emulsified wastewater containing oil or fuel contaminants with a low content of highly dispersed particles of inorganic nature or a stabilizer is present in them, it is advisable to use the flotation method with flotation units of pneumatic type. Analysing the results, it should be noted that the flotation method significantly reduces a purification time of highly dispersed emulsified wastewater from 3-5 hours of their settling in settling tanks-oil traps up to 10-20 minutes by a method of pneumatic flotation, while the degree of wastewater treatment increases in at least 1.5-2 times depending on the presence of fuel or oil contaminants in wastewater. If wastewater contains a stabilizer, such as a surfactant, it can be used as an effective flotation reagent in the purification of this type of wastewater by a flotation, which is not suitable for the settling process.Документ Відкритий доступ Biological wastewater treatment in context of circular economy(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Dzihora, Y.; Stolyarenko, H.With the beginning of the Anthropocene epoch, nature is facing a lot of environmental problems that drastically increased in the last century. At the current rate of resource consumption, soon nature will lose the ability for self-restoration. In order to avoid the inevitable consequences of resources exploitation, new approaches should be developed in all areas of human life. Linear economy concepts that were utilized for a long time and were based on the use and disposal of each separate resource depending on the purpose are not sufficient anymore. A more holistic approach should be applied to overcome the challenges that we are facing now. The application of circular economy concepts for wastewater treatment facilities has a great potential to enhance the sustainability of water management. This paper will focus on circular economy concepts applied for modern pilot installation that combines biological treatment and membrane separation and discusses the potential for full-scale implementation. Since the pilot plant was operated without any chemicals addition it eases the use of the waste sludge that is received as a by-product for different purposes as agricultural application and biogas production.