Environmental Problems
Permanent URI for this communityhttps://ena.lpnu.ua/handle/ntb/33081
Browse
6 results
Search Results
Item Dynamics of carbon dioxide adsorption by carbon nanotubes(Видавництво Львівської політехніки, 2023-02-28) Sabadash, Vira; Gumnitsky, Jaroslaw; Lopushansky, Oleksiy; Matsuska, Oksana; Nowik-Zając, Anna; Lviv Polytechnic National University; Lviv National University of Veterinary Medicine and Biotechnologies named after S. Z. Gzhytskyi; Jan Dlugosz University in CzestochowaThis article is devoted to the study of the carbon dioxide adsorption process. The relevance of using carbon nanotubes for adsorbing carbon dioxide from industrial emissions is that carbon nanotubes have a high surface area and can effectively interact with carbon dioxide molecules. In addition, they have high mechanical strength and chemical resistance, which makes them attractive for industrial use. Carbon nanotubes have the potential to reduce carbon dioxide emissions and reduce the negative impact on the environment. Using carbon nanotubes in the industry can help reduce greenhouse gas emissions and the environmental impact of burning fossil fuels. Purpose. The work aimed to study the prospects of using carbon nanomaterials to purify industrial emissions from carbon dioxide in a fluidized state. The scientific novelty of the topic "Dynamics of carbon dioxide adsorption by carbon nanotubes" is the study of the influence of temperature and gas velocity on the initial curves of CO2 adsorption dynamics in the fluidized state.Item Static regulations of urea (carbamide) adsorption by wet and dried peat(Видавництво Львівської політехніки, 2023-02-28) Matsuska, Oksana; Sukhorska, Olga; Gumnitsky, Jaroslaw; Sabadash, Vira; Lviv Polytechnic National UniversityThe possibility and effectiveness of using a natural sorbent – peat from the Vereshchytsia-Yanivske deposit for treating agricultural wastewater with a high urea content – has been studied. The humidity and moisture content of the upland and lowland types of peat from this peatland were determined. Comparing these indicators made it possible to establish that the lowland peat has a significantly higher humidity and moisture content. The adsorption capacities of wet and dried types of peat for urea were studied and compared. The changes in urea concentration in aqueous solutions of the studied peat samples are presented by the corresponding curves. It was established that the lowland peat (dried samples) has higher sorption properties to urea when absorbed from the water environment than the upland type. In the adsorption of non-dried peat, curves were obtained, which show a gradual decrease in the concentration of urea in the solution, indicating the gradual filling of the active centres of peat with urea molecules. For pre-dried peat, rapid absorption of this pollutant is observed at the initial moments (approximately up to 10 minutes). The calculated maximum absorption capacities of dried peat species for urea show that the maximum absorption capacity of dry lowland peat is significantly higher than that of dry upland peat.Item Use of Modified Adsorbents to Remove Pesticides From Wastewater(Видавництво Львівської політехніки, 2022-03-01) Sabadash, Vira; Gumnitsky, Jaroslaw; Nowik-Zając, Anna; Zawierucha, Iwona; Krylova, Galyna; Lviv Polytechnic National University; Academy of Jan Dlugosz in CzestochówThe migration of highly concentrated pesticide solutions in the soil has been experimentally studied. A mathematical model of the diffusion process in the soil environment has been developed. Based on the mathematical model, a system of equations for calculating the duration and intensity of the process depending on environmental parameters was obtained. The dependence of the process velocity on the direction of the diffusion front is determined, and the diffusion coefficients, kinetic coefficients of the diffusion process and the diffusion front velocity were calculated. Environmental aspects of pesticide migration were analysed. The diffusion coefficient of glyphosate in the model soil environment is established. Under the experimental conditions, the diffusion coefficient value was D = 1.755×10-12 m2/s. The study results of the process of migration of the component up the soil profile indicate the mechanism of molecular diffusion of glyphosate in the soil environment. The results of experimental research and the solution of the mathematical model were used to model the migration process in the Comsol Multiphysics environment. Analysis of theoretical and experimental results showed that the developed model could be used to calculate the dynamics of the spread of the pesticide front in the soil with sufficient accuracy.Item Extraneous diffusion kinetics of ammonium ions adsorption in the presence of other ions(Видавництво Львівської політехніки, 2022-06-01) Sabadash, Vira; Gumnitsky, Jaroslaw; Petrus, Roman; Lviv Polytechnic National University; Pzeszów University of TechnologyThe article presents the results of the study of the kinetics of ions adsorption from multi-component mixtures. The isotherms of sorption of ammonium nitrogen in the presence of phosphates indicate a decrease in the exchange capacity of zeolite due to its competition for active absorption centres. This study was carried out with two ions of inorganic nature. In the presence of the third organic component in the solution (protein substance – albumin), the sorption capacity of zeolite decreases even more in comparison with ammonium ions. It was found that in the presence of phosphates, the equilibrium capacity of zeolite towards ammonium decreases by about 30 %; in the three-component system the reduction reaches about 70 %.Item Simulation of ion exchange interaction kinetics in the clinoptylolite – ammonium ion system(Видавництво Львівської політехніки, 2021-06-01) Sabadash, Vira; Gumnitsky, Jaroslaw; Omelyanova, Sofia; Lviv Polytechnic National UniversityThe kinetics of adsorption of ammonium ions under dynamic conditions has been studied. A mathematical model of the process was built. The mass transfer coefficient was calculated depending on the intensity of the change of location. It was established that ion exchange occurs in external and internal diffusion regions. The rate constants of ion exchange for the region of external and internal diffusion were calculated.Item Investigation of the process of fluoride ions adsorption by natural sorbents(Видавництво Львівської політехніки, 2021-03-01) Sabadash, Vira; Liuta, Oksana; Gumnitsky, Jaroslaw; Lviv Polytechnic National UniversityA detailed analysis of literature sources on the content of fluorides in the environment, methods of conditioning and defluoridation of water was held. The mechanism of interaction of fluorides with zeolite in the process of adsorption treatment of wastewaters and domestic waters was clarified. It was first established that in the process of adsorption there is the formation of magnesium fluoride compounds due to the binding of cations extracted from the zeolite by the mechanism of ion exchange. The mechanism of chemisorption of fluoride ions by the formation of insoluble CaF2 was also proved. According to the results of experimental research, a technological scheme has been developed, which provides the preliminary treatment of fluoride ions in the form of complexes with aluminium. In order to prevent the permeation of aluminium fluoride into the treated water, a stage of adsorption water purification was proposed. Calculations of the amount of reagent necessary to ensure the required degree of purification of water from fluoride ions were done. The statistical parameters of the process and the significance of the obtained results were calculated. The coefficient of determination of experimental data was 0.87…0.99, the standard deviation was 0.017…0.026.