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Problems of plastics and microplastics in FTIR analysis of soils
Stanislavová, Veronika ; Kučerík, Jiří (oponent) ; Doležalová Weissmannová, Helena (vedoucí práce)
Microplastics are formed as the result of the fragmentation of plastics. The microparticles are easier to distribute and thus can contaminate the environment. Recently, there has been an increasing interest in the research of microplastics present in the soil system, using different methodologies. The focus of this thesis is the analysis of microplastics in soil using infrared spectroscopy – ATR (attenuated total reflectance) and DRIFT (diffuse reflectance) techniques. This work aimed to evaluate the suitability of the method for the identification of microplastics in soils. Polymers such as polyethylene terephthalate (PET), poly-3-hydroxybutyrate (PHB) and polylactic acid (PLA) were used. In the first part of experimental analysis were microplastics mixed in different concentrations with 3 different types of model soils. The obtained infrared spectra of samples of mixtures (model soil and plastics) were used for statistical evaluation. The second part of the measurement was focused on the monitoring of changes in the spectra of real soils spiked with PET, after exposure to the degradation. After the interpretation of infrared spectra of samples of plastics with real and model soil, it was possible to confirm the presence of the functional groups of each polymer. Based on the measurements, the used techniques were evaluated as inappropriate for the qualitative determination of PLA. The results of the experimental part confirm the accuracy of FTIR (both ATR and DRIFT) for the analysis of microplastics in soil for samples containing PET and PHB.
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Influence of bioplastic biodegradation on soil properties
Stanislavová, Veronika ; Zlámalová Gargošová, Helena (oponent) ; Kučerík, Jiří (vedoucí práce)
Biodegradable plastics are gaining popularity as a desirable material in the market, particularly in the agricultural sector, where they are used as coatings and mulch films due to their favourable properties. This study investigated the impact of poly-3-hydroxybutyrate (P3HB), an intracellular bacterial polymer, on various soil properties, including physical, chemical, and biological aspects, to assess its potential in agricultural use. Results showed that the P3HB had a negative effect on the soil dry matter content, aboveground biomass, and a slight decrease in soil pH. Moreover, the activity of selected enzymes was significantly enhanced when P3HB applicated solely or even more increased when combined with a specific amendment. The results varied depending on the amendment; the effects were negative, neutral or positive. The thermogravimetry analysis was used to assess the rate of P3HB biodegradation and the influence of P3HB on organic matter and water retention. It was found that the presence of amendment influenced the degradation rate of P3HB and other organic matter in the soil. Furthermore, the application of P3HB into the soil leads to the inhibition of plant (Zea mays L.) growth. The additions of amendments to soil prior to the application of P3HB improved this effect only marginally. It is concluded that biodegradation of P3HB supported the activity of the microbial community, which could eventually negatively influence the availability of essential nutrients in the soil. The thermogravimetric analysis demonstrated that the incorporation of organic amendments promoted the biodegradation of P3HB. Moreover, the results indicate that a combination of P3HB and biochar could improve soil water retention.
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Problems of plastics and microplastics in FTIR analysis of soils
Stanislavová, Veronika ; Kučerík, Jiří (oponent) ; Doležalová Weissmannová, Helena (vedoucí práce)
Microplastics are formed as the result of the fragmentation of plastics. The microparticles are easier to distribute and thus can contaminate the environment. Recently, there has been an increasing interest in the research of microplastics present in the soil system, using different methodologies. The focus of this thesis is the analysis of microplastics in soil using infrared spectroscopy – ATR (attenuated total reflectance) and DRIFT (diffuse reflectance) techniques. This work aimed to evaluate the suitability of the method for the identification of microplastics in soils. Polymers such as polyethylene terephthalate (PET), poly-3-hydroxybutyrate (PHB) and polylactic acid (PLA) were used. In the first part of experimental analysis were microplastics mixed in different concentrations with 3 different types of model soils. The obtained infrared spectra of samples of mixtures (model soil and plastics) were used for statistical evaluation. The second part of the measurement was focused on the monitoring of changes in the spectra of real soils spiked with PET, after exposure to the degradation. After the interpretation of infrared spectra of samples of plastics with real and model soil, it was possible to confirm the presence of the functional groups of each polymer. Based on the measurements, the used techniques were evaluated as inappropriate for the qualitative determination of PLA. The results of the experimental part confirm the accuracy of FTIR (both ATR and DRIFT) for the analysis of microplastics in soil for samples containing PET and PHB.
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