In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be “home-compostable” to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and from municipal composting plant experiments. Material properties, environmental conditions, and microbiology data were recorded during some of these experiments to document the biodegradation process and changes on the surface and inside the materials on a molecular level.

The main problems of the city of Nitra (Slovak Republic) in the field of municipal waste management include: 1. High production of municipal waste per capita; 2. Low rate of its separation; 3. High landfill rate; 4. No opportunity for composting; 5. Establishment of illegal landfills in the city; 6. Low waste prevention rate. To identify the attitudes and opinions of the respondents, and to evaluate certain behavioural practices of the inhabitants of Nitra in the management of municipal solid waste, we used a structured questionnaire (realized in 2020). The results of the questionnaire correspond to the behaviour of 4911 inhabitants of the city (6.46%). This paper evaluates the respondents’ answers, which could be utilised by the local government—not only for a more appropriate setting of municipal waste management and separation, but also in waste prevention and monitoring changes in the consumer behaviour of city residents. The degree of separation in individual housing construction (IHC) and complex housing construction (CHC) was statistically evaluated and compared separately. For paper and glass, a higher degree of separation was reflected in CHC; while conversely, households living in CHC avoided bio-waste and kitchen waste more than IHC households. The most common reason for not participating in the separate collection was the lack of collection containers, the distance of containers from their households, or the low frequency of their collection. The results of the questionnaire show the need for more rigorous education about waste generation, its proper separation, and its prevention.

Water stress is an indicator that plant are suffering from drought. For optimization of the crop production is necessary to indicate physiological changes, those can be represented by stem expansion or shrinkage and sap flow rate. We used the Dynagage SGA5-WS (Dynamax) sensors for the sap flow monitoring and the sensors Diameter Dendrometer Small (Ecomatik) for measuring branches diameter changes in our research. The research was realized during two seasons, in the summer (from 31 st July to 14 th August 2018) and in the spring (from 27 th March to 14 th April 2019). The subject in our research were walnut trees (Juglans regia) situated in the private orchard in Nové Zámky area in Slovak Republic. The sap flow values in summer were on average range of 90 g•h -1 , with maximum measured values above 160 g•h -1 measured after the precipitation events. After increasing of soil moisture on 1 st and 2 nd August 2018, it was detected the branches diameter expansion up to 0.05 mm. However, the other spring values were much lower. The sap flow reached less than 35 g•h -1 what was one third values in summer 2018. This phenomenon is a result of the low transpiration intensity of transpiration or a leafless state of trees. Although the changes in diameter were not significant in the early vegetation stage, there were monitored some fluctuation causing the diameter was shrinked by 0.2 mm due to a negative average air temperature.

The paper represents a waste composition study that was conducted at the Mladosť dormitory of the Slovak University of Agriculture (SUA) in Nitra. The aim of the study was to determine the amount and composition of waste generated in the dormitory and to provide recommendations for enhancing the recycling rates and to improve the overall sustainability of waste management in the dormitory. The analysed solid waste was separated into organics, papers, plastics, glass, metals, cardboard beverage packaging (tetrapak), electronic waste (e-waste), and others. The estimated annual average quantity of waste generated per student of the dormitory is 38 kg. The composition of generated solid waste is as follows: paper (6%), glass (26%), plastic (9%), metal (4%), organic (28%), tetrapak (2%), e-waste (1%) and other waste (24%). Potential recycling rate of generated waste is 76%. Composting is the most sustainable method to convert organic waste into valuable compounds and to reduce the waste disposed into landfills.

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