Environmental Problems

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Subject: search.filters.subject.diffusion

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    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 Czestochów
    The 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.
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    Dynamics modeling of traffic-related exhaust aerosols
    (Lviv Politechnic Publishing House, 2017-11-12) Sheludchenko, Lesya; Kamyanets-Podilsky, Khmelnitsky region
    The results of analytical researches of migration processes and turbulent diffusion of exhaust aerosols, produced by traffic flows within reserve technical lanes of highways are given. It is concluded that rotors, determined as some areas of the rotary motion of an aerosol, are always formed within the diffusion divergence field of turbulent flows of exhaust aerosol.
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    Dynamics modeling of traffic-related exhaust aerosols
    (Lviv Politechnic Publishing House, 2017-11-12) Sheludchenko, Lesya; Kamyanets-Podilsky, Khmelnitsky region
    The results of analytical researches of migration processes and turbulent diffusion of exhaust aerosols, produced by traffic flows within reserve technical lanes of highways are given. It is concluded that rotors, determined as some areas of the rotary motion of an aerosol, are always formed within the diffusion divergence field of turbulent flows of exhaust aerosol.
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    Decontamination of radioactive liquid systems by modified clay minerals
    (Publishing House of Lviv Polytechnic National University, 2016) Petrushka, Ihor; Moroz, Olexandr
    The process mechanism for sorption of strontium and cesium from liquid radioactive waste using modified bentonites from Yaziv sulfur deposit was investigated. The technique for predicting the intensity of the sorption process based on the comparison of experimental and calculated values of mass transfer coefficients was proposed. It was detected that the process of sorption extraction of strontium and cesium from liquid medium using modified clay minerals may be best described by a three-parameter model of the adsorption isotherms.