Výskyt mikroplastů v životním prostředí a možnosti jejich recyklace

SP2024/009

The topic of the project is completely in line with the strategic plan of FMT, especially in the areas of "Waste processing technology" and "Multifunctional smart (nano)materials for industrial and environmental applications". Microplastics are one of the most important environmental pollutants. They are plastic particles with sizes from 1 μm to 5 mm. As a result of their small dimensions, they have a large specific surface area and, in addition, they show remarkable chemical stability. Microplastics are created by the disintegration, fragmentation and weathering of plastic waste in the environment. Another way of their formation is the transport of synthetic microspheres used in cosmetics and personal care products, abrasion of plastic materials and tires and synthetic textiles. Microplastics can be found in the atmosphere, soil, sediments, aquatic systems such as the marine environment, drinking water, wastewater treatment effluents, soil water and freshwater systems. In the last few years, the issue of their removal and recycling in order to produce useful chemicals for further use in industry has come to the fore. In the SGS project, the possibilities of monitoring their occurrence in the aquatic environment, soils, sewage sludge and biomass processing products will be studied. Furthermore, the project will deal with the possibilities of their degradation through the action of microorganisms and with the help of photocatalytic decomposition and transformation into other substances, the so-called photoreforming. Individual research tasks are described in activities I, II and III. Activity I – monitoring the occurrence of microplastics Microplastics can be found in the atmosphere, soil, sediments, aquatic systems such as the marine environment, drinking water, wastewater treatment effluents, soil water and freshwater systems. The aim of this part of the research will be to monitor the presence of microplastics in soils, composts (municipal composting plant OZO Ostrava Hrušov), sludge (UČOV Ostrava), waters, anaerobic digestates from gas stations (Energetické centrum Horní Suchá), etc. Infrared microscopy, pyrolysis gas chromatography and high-performance liquid chromatography. The goal of this activity will be to introduce these analytical methods for monitoring microplastics in real conditions, optimize their parameters and obtain completely unique information about the distribution of microplastics in selected locations of Ostrava and the Moravian-Silesian region. Activity II – anaerobic digestion of microplastics Degradation of microplastics can occur naturally or be carried out purposefully, for example, by biochemical processes with the participation of biocatalysts (enzymes) produced by microorganisms. These processes are important from the point of view of the behaviour of microplastics in soils, sediments, but also in sewage sludge. Anaerobic digestion experiments and, depending on time availability, aerobic fermentation of biodegradable mixtures containing microplastics will be carried out. These experiments will contribute to the understanding of the behaviour of microplastics in the environment or in cleaning or energy processes. At the same time, research will be conducted on the interaction of microplastics with other micropollutants, especially drugs and pesticides, the interaction of which can have a significant negative effect on living organisms. Ecotoxicity tests of microplastic particles collected from the environment will also be part of the research. Activity III – photoreforming of microplastics Photocatalytic degradation of microplastics is an innovative approach to the disposal of microscopic plastic particles using photocatalysts and sunlight or visible light. One of the basic principles of this method is the selection of a suitable photocatalyst with properties that allow the absorption of sunlight or visible light. These are often materials such as titanium dioxide or graphitic carbon nitride, which are widely used for their photocatalytic activity. The absorbed energy generates electrons and holes in the photocatalyst structure. The generated charge carriers then create highly reactive radicals that cause the degradation of plastic polymers. The photocatalytic degradation process generates products such as hydrogen, hydrocarbons or organic acids (e.g. formic acid, acetic acid, etc.), which can be further used. Before photoreforming itself, the microplastic particles will be subjected to a suitable pre-treatment, for example alkaline hydrolysis, in order to achieve optimal activation. The effect of this pre-treatment on the results of photoreforming will be investigated more thoroughly to better understand the overall process. Photocatalytic degradation of microplastics is a sustainable approach as it uses renewable energy sources (solar or visible light) and minimizes the need for chemicals or energy from non-renewable sources. This method provides a promising solution for the effective elimination of microplastics with minimal environmental impact.

2024

2024

Ministerstvo školství, mládeže a tělovýchovy

SGS

Specifický výzkum VŠB-TUO

Praus Petr prof. Ing., Ph.D.