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Biodegradable plastics
Schifferová, Zuzana ; Jan, Vít (referee) ; Molliková, Eva (advisor)
The aim of this bachelor theses is to discuss the process of biodegradation occurring with biodegradable polymers including factors affecting this process. The theses also introduces some types of biodegradable plastics including their properties. At last it discusses waste management of these plastics and their ecological impact.
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Influence of biodegradable polymers microplastics on properties of soil organic matter
Denková, Pavla ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
The microplastics contamination is an issue observed in all environmental compartments. Currently, the trend is to replace the synthetic polymers by biodegradable ones, which are expected to degrade faster due to omnipresent microorganisms. However, this assumption may not correspond with the reality. In nature, biodegradation can last long or not whatsoever and the microparticles of biodegradable polymers can remain in soil the same way as particles of synthetic polymers. The effect of microparticles of biodegradable polymers on soil´s biota has already been studied, but the effect on the properties of soil and water in the soil has not been elucidated yet. This thesis deals with the influence of microparticles of biodegradable plastics on the physico-chemical properties of soil organic matter, especially on the behavior of water in the soil system under arid and semiarid conditions. Microparticles of poly(R-3-hydroxybutyrate), abbreviated as P3HB, were used as a model biodegradable polymer and were introduced into the soil in various concentrations. To determine the evaporation enthalpy of water and stability of water bridges that affect (stabilize) the physical and chemical structure of soil organic matter Differential Scanning Calorimetry (DSC) was used. Simultaneously was also measured their effect on water holding capacity of soil organic matter. Under experimental conditions, P3HB microplastics were found to reduce evaporation enthalpy, which facilitates drying of soil organic matter. Nevertheless, their effect on final water holding capacity was relatively low. Besides, we observed a negative effect on the stability of water molecule bridge that connect segments of soil´s organic components. Thus, P3HB microparticles in soil could pose a risk due to their influence on the water retention mechanism in soil under arid and semiarid conditions.
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Influence of biodegradation of polyhydroxyalkanoates on soil properties and composition
Denková, Pavla ; Doležalová Weissmannová, Helena (referee) ; Kučerík, Jiří (advisor)
Biodegradable plastics are presented as a promising replacement for synthetic polymers. In soil, they are expected to be fully degraded by micro-organisms within a short time and to be inherently harmless to the environment. However, this assumption needs to be verified, and it is important to pay attention to the impact on soil´s biota as well as the effect of the biodegradation process could have on soil properties, composition and structure. In this work was studied the effect of biodegradation of poly(R-3-hydroxybutyrate), (P3HB), belonging to the group of polyhydroxyalkanoates, on the structure and physicochemical properties of soil. P3HB particles were mixed in different concentrations with soil in which biodegradation experiments were carried out under different conditions - i.e. with and without growing plant, with and without nitrogen fertilization. After 90 days, were soil analyzed. Thermogravimetry was used to determine the amount of residual non-degraded micro-bioplastics and to determine the effect of biodegradation on the properties of soil organic matter. Differential scanning calorimetry provided information on the effect of biodegradation on the evaporation enthalpy of adsorbed water from the soil, while the amount of water in the soil was also determined. Furthermore, the effect on field water holding capacity was determined and sieve analysis of individual samples was performed to characterize the effect of biodegradation on soil particle size distribution. Biodegradation conditions were shown to affect not only the rate of biodegradation but also some soil parameters. As expected, biodegradation of P3HB was proved to be faster in a nutrient-rich environment. In contrast, lack of nitrogen in soil with growing plant caused a decrease in the evaporation enthalpy of water and a reduction in the amount of water in soil, which can lead to easier soil drying and cause stress conditions for plant growth. Increased soil particle aggregation was observed in all sample series with P3HB compared to soils without P3HB addition.
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Influence of microbioplastics on aquatic plants
Mácová, Sabina ; Maršálková, Eliška (referee) ; Kučerík, Jiří (advisor)
Plastic pollution is becoming a serious environmental problem, for this reason, in recent years efforts have been made to propose alternatives to conventional plastics. Biodegradable plastics appeared to be a possible alternative due to similar properties to synthetic plastics and because they are considered safe and degradable in the environment. However, under real conditions, biodegradation is a relatively time-consuming process that can lead only to biofragmentation into small particles, co-called microbioplastics. So far, very little is known about their impact on the environment. This work deals with the ecotoxicological influence of biodegradable poly(3-hydroxybutyrate) (P3HB) microparticles in two size fractions (particles
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Influence of biodegradation of polyhydroxyalkanoates on soil properties and composition
Denková, Pavla ; Doležalová Weissmannová, Helena (referee) ; Kučerík, Jiří (advisor)
Biodegradable plastics are presented as a promising replacement for synthetic polymers. In soil, they are expected to be fully degraded by micro-organisms within a short time and to be inherently harmless to the environment. However, this assumption needs to be verified, and it is important to pay attention to the impact on soil´s biota as well as the effect of the biodegradation process could have on soil properties, composition and structure. In this work was studied the effect of biodegradation of poly(R-3-hydroxybutyrate), (P3HB), belonging to the group of polyhydroxyalkanoates, on the structure and physicochemical properties of soil. P3HB particles were mixed in different concentrations with soil in which biodegradation experiments were carried out under different conditions - i.e. with and without growing plant, with and without nitrogen fertilization. After 90 days, were soil analyzed. Thermogravimetry was used to determine the amount of residual non-degraded micro-bioplastics and to determine the effect of biodegradation on the properties of soil organic matter. Differential scanning calorimetry provided information on the effect of biodegradation on the evaporation enthalpy of adsorbed water from the soil, while the amount of water in the soil was also determined. Furthermore, the effect on field water holding capacity was determined and sieve analysis of individual samples was performed to characterize the effect of biodegradation on soil particle size distribution. Biodegradation conditions were shown to affect not only the rate of biodegradation but also some soil parameters. As expected, biodegradation of P3HB was proved to be faster in a nutrient-rich environment. In contrast, lack of nitrogen in soil with growing plant caused a decrease in the evaporation enthalpy of water and a reduction in the amount of water in soil, which can lead to easier soil drying and cause stress conditions for plant growth. Increased soil particle aggregation was observed in all sample series with P3HB compared to soils without P3HB addition.
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Influence of biodegradable polymers microplastics on properties of soil organic matter
Denková, Pavla ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
The microplastics contamination is an issue observed in all environmental compartments. Currently, the trend is to replace the synthetic polymers by biodegradable ones, which are expected to degrade faster due to omnipresent microorganisms. However, this assumption may not correspond with the reality. In nature, biodegradation can last long or not whatsoever and the microparticles of biodegradable polymers can remain in soil the same way as particles of synthetic polymers. The effect of microparticles of biodegradable polymers on soil´s biota has already been studied, but the effect on the properties of soil and water in the soil has not been elucidated yet. This thesis deals with the influence of microparticles of biodegradable plastics on the physico-chemical properties of soil organic matter, especially on the behavior of water in the soil system under arid and semiarid conditions. Microparticles of poly(R-3-hydroxybutyrate), abbreviated as P3HB, were used as a model biodegradable polymer and were introduced into the soil in various concentrations. To determine the evaporation enthalpy of water and stability of water bridges that affect (stabilize) the physical and chemical structure of soil organic matter Differential Scanning Calorimetry (DSC) was used. Simultaneously was also measured their effect on water holding capacity of soil organic matter. Under experimental conditions, P3HB microplastics were found to reduce evaporation enthalpy, which facilitates drying of soil organic matter. Nevertheless, their effect on final water holding capacity was relatively low. Besides, we observed a negative effect on the stability of water molecule bridge that connect segments of soil´s organic components. Thus, P3HB microparticles in soil could pose a risk due to their influence on the water retention mechanism in soil under arid and semiarid conditions.
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Možnosti zpracování bioplastů
Dymchenko, Alan
This diploma thesis is focused on the issues relating to bioplastics and the possibilities of its processing. The first part of the diploma thesis deals with the issue of plastic packaging. Description of the history of plastic formation, plastics production and characteristics of bioplastics. It answers questions – what plastic is and why we need to degrade it. Classification of the most widespread in the use of bioplastics. Statistics on the production of bioplastics. Possibilities of processing of bioplastics. Factors that affect the decomposition of bioplastics. The second part of the diploma thesis is dedicated to laboratory tests, methodology of execution and analysis of laboratory results. It also describes the realization of self-attempted composting of bioplastics in domestic conditions.
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Biodegradable plastics and their impact on waste management
Štefánek, Ján
This bachelor thesis aims at biodegradable plastics and their use. It contains a general overview of biodegradable plastic materials, information about basic materials for their production in comparison with conventional fossil plastics and last but not least economical and statistical view on manufacturing and using these new, highly perspective materials.
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Biodegradable plastics in the waste management system
Šalanda, Pavel ; Innemanová, Petra (advisor) ; Hnátková, Tereza (referee)
Plastics are currently widely used material. Their disadvantage is bad environmental sustainability. Therefore, since the 1970s new materials have been searched for that would be able to replace the old ones. The most successful is the production of so-called biodegradable plastics (or in general bioplastics). We get them mainly from plant substrates, they have great diversity (300 types) and quite different properties. Currently they have been implemented into practice but their production does not exceed 1% of total plastic production so far. The thesis deals with the question how to handle these materials at the end of their life. In the first part the behaviour of biodegradable plastics in particular end devices and their consequences are outlined. The objective is to choose the best possible disposal option. Comparing recycling with conventional plastics, composting, anaerobic digestion, incineration or landfilling, the best option is to lead their waste stream to energy recovery facilities. Several bioplastics degrade well in aerobic conditions of composting plants or anaerobic reactors of biogas plants. However, surface disposal is in a universal way is possible due to different properties only by the burning process. The second, final part deals with the optimization of the operation of...
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Biodegradable plastics
Schifferová, Zuzana ; Jan, Vít (referee) ; Molliková, Eva (advisor)
The aim of this bachelor theses is to discuss the process of biodegradation occurring with biodegradable polymers including factors affecting this process. The theses also introduces some types of biodegradable plastics including their properties. At last it discusses waste management of these plastics and their ecological impact.
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