Municipal waste management in Poland has continuously changed over the past years regarding collection systems and disposal processes. After joining the EU, the approach to waste management changed dramatically, intensifying selective collection and implementing recovery and treatment processes. Recent years have shown that a further fundamental overhaul in the waste sector is needed to convert the sector to a closed-loop economy. These challenges are appearing in Poland, forcing actions in which the efficiency of the waste stream management system should generate added value in the form of sourced raw materials, materials and products. The waste generated should be managed following the waste hierarchy, in which disposal is the least desirable process. The work aims to analyse the current state of municipal waste management in Poland concerning applicable legal requirements, waste management hierarchy and the use of the best available technologies. The data from the analysis was used to determine where Poland is currently, heading towards transforming to a circular economy in the technological, social, environmental and economic areas. The research results showed the need to reduce the waste generated, including a significant reduction in the amount of waste stored in landfills and a significant increase in the recycling rates of municipal waste. In this context, supporting the transition to a closed-loop economy is essential in creating a low-carbon, recycling and innovative waste management, implementing EU strategies.

The aim of the study was to determine the removal efficiency of 16 polycyclic aromatic hydrocarbon (PAH) (Σ 3-, 4-, 5-, and 6-ring PAHs) from aqueous solution using dihydrogen dioxide in the presence of cobalt, platinum, and titanium catalysts. The research was based on the determination of the COD (Total Organic Carbon) in aqueous solution (distilled water with a standard mixture of 16 PAHs). On the basis of the determined value of COD, the oxidant dose—30% solution of dihydrogen dioxide—was calculated. Adequate amounts of dihydrogen dioxide and catalyst were added to the samples. The samples were mixed and left in laboratory conditions for 12 h. Then, PAHs were determined in duplicate. The analysis of PAHs included sample preparation and quantitative and qualitative chromatographic determination, which was performed using a gas chromatograph coupled to a mass spectrometer. The use of a cobalt catalyst resulted in the removal of 16 PAHs in 25%. A dose of an oxidant in the amount of 0.818 mL per liter of the analyzed sample was used. An increase in the amount of dihydrogen dioxide led to higher oxidation efficiency—31% and it gave the final concentration of 1,978 ng/L. Platinum catalyst caused the removal of 16 PAHs by 32%, reaching the final concentration of 1,940 ng/L. The best result for the removal of PAHs was achieved using a titanium catalyst. The amount of oxidant equal to 0.818 mL per liter of the analyzed sample caused a 91% decrease in the summary concentration of 16 PAHs.

Sustainable socioeconomic development should provide humans with a suitable environment for safe living. It can be debated whether the term “environment” should be used due to the significant anthropogenic transformation of the environment. Therefore, an essential part of solving environmental problems is innovation. Climate, resource conservation, and environmental protection are recognized worldwide as common challenges. Thus, it is necessary to implement solutions that simultaneously protect the environment and the climate with sustainable and rational use of resources. Related to this issue is the principle of a loop/closed-loop economy. Among other things, it refers to using waste to prepare materials that can be used for other purposes. The use of tools such as LCA (life cycle analysis) contributes to supporting environmental protection. With the LCA method, it is possible to analyze environmental risks and compare new technological alternatives. LCA is a methodology that has been used around the world with great success, especially for studying individual stages of the entire product life cycle. The results of studies that have been conducted in various research centers confirm the possibility of also using the LCA technique for the environmental assessment of new technologies or existing modernized technological processes. The purpose of this study was to assess the feasibility of using the LCA method to determine the environmental impact that the potential production and use of new materials will have.

Life Cycle Assessment, included in company environmental management methods, has particular importance in marketing management. Analysis of dangers to the environment through tools such as the LCA method allows for comparisons of alternative company management strategies. LCA is characterised as a technique for environmental management that enables environmental impact assessment of the product, process, industry, and even the comprehensive economic sector. LCA also influences decisions regarding environmental policy modification, but most importantly, it influences a company's marketing activities. The LCA technique is applied the world over with great effectiveness in studying specific phases of a product's life cycles – from 'birth to death'; however, Poland's experience in this domain constitutes continuously developing research areas. The experience of foreign research centres confirms the possibility of applying LCA techniques in supporting environmental risk assessment of innovative technologies where LCA is used to study the environmental impact of a new generation product, i.e. flocculants from polymer wastes. This article presents the results of a study of the effectiveness of applying a new generation of polyelectrolyte (gained from polystyrene waste) in treating industrial wastewater and the LCA environmental impact assessment, which was carried out using SimaPro software. Based on the analysis of the results of the application of sodium salts of sulfone derivatives of polystyrene in the treatment of mine water, it was found that these products significantly reduced the pollution indicators of mine water from KWK1. Accordingly, they provided the basis for the development of technical-scale technology.

The subject of the study was the osmotic volume transport of aqueous CuSO₄ and/or ethanol solutions through a selective cellulose acetate membrane (Nephrophan). The effect of concentration of solution components, concentration polarization of solutions and configuration of the membrane system on the value of the volume osmotic flux ( $J_{vi}^r)$ in a single-membrane system in which the polymer membrane located in the horizontal plane was examined. The investigations were carried out under mechanical stirring conditions of the solutions and after it was turned off. Based on the obtained measurement results $J_{vi}^r$ , the effects of concentration polarization, convection polarization, asymmetry and amplification of the volume osmotic flux and the thickness of the concentration boundary layers were calculated. Osmotic entropy production was also calculated for solution homogeneity and concentration polarization conditions. Using the thickness of the concentration boundary layers, critical values of the Rayleigh concentration number ( $R_C^r$ ), i.e., the switch, were estimated between two states: convective (with higher $J_{vi}^r$ ) and non-convective (with lower $J_{vi}^r$ ). The operation of this switch indicates the regulatory role of earthly gravity in relation to membrane transport.