The article discusses an innovative system used for aerobic biostabilisation and biological drying of solid municipal waste. A mechanical–biological process (MBT) of municipal solid waste (MSW) treatment were carried out and monitored in 5 bioreactors. A two-stage biological treatment process has been used in the investigation. In the first step an undersize fraction was subjected to the biological stabilisation for a period of 14 days as a result of which there was a decrease of loss on ignition, but not sufficient to fulfill the requirements of MBT technology. In the second stage of a biological treatment has been applied 7-days intensive bio-drying of MSW using sustained high temperatures in bioreactor. The article presents the results of the chemical composition analysis of the undersize fraction and waste after biological drying, and also the results of temperature changes, pH ratio, loss on ignition, moisture content, combustible and volatile matter content, heat of combustion and calorific value of wastes. The mass balance of the MBT of MSW with using the innovative aeration system showed that only 14.5% of waste need to be landfilled, 61.5% could be used for thermal treatment, and nearly 19% being lost in the process as CO2 and H2O.

One of the major tasks of municipal waste management in European Union countries is the systematic reduction of waste that is removed and transported to landfills. This refers particularly to biodegradable waste. One of the methods employed to decrease waste amount is Mechanical-Biological Treatment (MBT) of the waste, before it is stored.

The article presents characteristics of MSW and biologically pre-treated municipal solid waste, organic carbon loads emitted in biogas and leachate during waste deposition in a landfill. Its decomposition rate constants were determined on the basis of modified Zacharof and Butler’s stochastic model. The values of decomposition rate constants determined for MSW had similar change trends to those presented in the literature: the hydrolysis constant had the lowest value (2.6 × 10-5 d-1), the highest acid phase constant (4.1 × 10-4 d-1), while the methane phase constant - 2.2 × 10-4 d-1. The PMSW decomposition rate constants in each anaerobic waste degradation phase had similar change trends, though their values were higher, by 21, 11 and 19%, respectively.

The introduction highlights the technologies of converting the chemical energy of biomass and municipal waste into various forms of final energy (electricity, heat, cooling, new fuels) as important in the pursuit of a low-carbon economy, especially for energy and transport sector. The work continues to focus mainly on gasification as a process of energy valorization of the initial form of biomass or waste, which does not imply that other methods of biomass energy use are not considered or used. Furthermore, the article presents a general technological flowchart of gasification with a gas purification process developed by Investeko S.A. in the framework of Lifecogeneration.pl. In addition, selected properties of the municipal waste residual fraction are described, which are of key importance when selecting the technology for its energy recovery. Significant quality parameters were identified, which have a significant impact on the production and quality of syngas, hydrogen production and electricity generation capacity in SOFC cells. On the basis of the research on the waste stream, a preliminary qualitative assessment was made in the context of the possibility of using the waste gasification technology, syngas production with a significant share of hydrogen and in combination with the technology of energy production in oxide-ceramic SOFC cells. The article presents configurations of energy systems with a fuel cell, with particular emphasis on oxide fuel cells and their integration with waste gasification process. An important part of the content of the article is also the environmental protection requirements for the proposed solution.

In the article, a device for measuring the parameters of the rotational movement of the auger for dewatering solid waste is proposed based on the analysis of signal processing methods and measurement of physical quantities. It can be used in the development of high-performance special vehicles for transporting waste as the main link in the structure of machines for the collection and primary processing of solid waste. The structural scheme of the means and block diagram of the microcontroller control program algorithm for implementation of the device for measuring the parameters of the rotational motion are proposed. The main technical characteristics of the proposed means are given. The results of experimental tests for measuring the parameters of rotational motion are shown. The results of experimental studies, which are given in the work, confirmed the reliability of the measured parameters.

Municipal waste is a global issue and they are generated in all countries around the world. Both in the European Union and the United States, a common method of non-recyclable waste utilization is thermal incineration with energy recovery. As a result of this treatment, residual waste like bottom ash, air pollution control residues and fly ashes are generated. This research shows that residues from waste incineration can be a potential source of critical raw materials. The analysis of the available literature prove that the residues of municipal waste incinerators contain most of the elements important for the US and EU economies. Material flow analysis has shown that each year, the content of elemental copper in residues may be 29,000 Mg (USA) and 51,000 Mg (EU), and the amount of rare earth elements in residues exceeds their mining in the EU. In the case of other elements, their content may exceed their extraction by even over 300%. The recovery of elements is difficult due to their encapsulation in the aggregate matrix. The heterogeneous nature of residues and the many interactions between different components and incineration techniques can make the process of recovery complicated. Recovery plants should process as much of the residues as possible to make their recovery profitable. However, policy makers from the EU and the US are introducing new legal regulations to increase the availability of critical raw materials. In the EU, new regulations are planned that will require at least 15% of the annual consumption of critical raw materials to come from recycling. Therefore, innovative technologies for recovering critical raw materials from waste have a chance to receive subsidies for research and development.

Composting of municipal solid waste with a 1 % addition of pulverized metallic iron, iron oxide(III) and iron sulfide(II) has been carried out. The amounts of iron in the bioavailable forms have been assayed in the composts obtained by means of speciation analysis, and the influence of composting on iron mobility has been evaluated. It has been found that pulverized metallic iron introduced into the waste occurs in the compost in the fractions easily accessible to plants, mainly the carbonate fraction. In the waste contaminated with Fe203 iron remains in the residual fraction, and composting does not practically increase its mobility. Over half of the iron from FeS remains in the waste in the residual fraction however, after composting there was an increased iron concentration in the bioavailable carbonate fraction.

In recent years, there has been a marked increase in the amount of municipal waste generated in Poland. In 2020, 21.6% of all municipal waste was subjected to a thermal treatment process. Consequently, the amount of ashes generated is significant. Due to their properties, it is difficult to utilize this type of waste within concrete production technology. One of the waste utilization methods is to add it to hardening slurries used in, among others, cut-off walls. The article assesses the possibility of using ashes from municipal waste incineration as an additive to hardening slurries. It also discusses the technological properties of hardening slurries with the addition of the ashes in question. The experiment showed that it is possible to compose a hardening slurry based on tested ashes with technological properties suitable for use as a cut-off wall. Further research directions were proposed.

Regions with warm climate are poor in organic matter or have a deficit of soil. The purpose of the work was to select the optimal mix from biodegradable wastes such as cardboard (Cb), natural textiles (Tx) newspaper (Np), colored newspaper (Cp), and office paper (Op) for creating artificial soil by combining these materials with compost and sand. To select the optimum mix, 15 samples were taken (3 from each type of waste in the following proportions: 25%, 50% and 75% ). The optimum mix was analyzed for grass germination rate and root development. Tests were performed in the laboratory with conditions similar to those of regions with warm climate and soil deficiency in a specially designed testing spot (bioterm). The effects of particular mixes on plant germination rate and growth were measured. Out of all mixes, the textile compositions Tx50 and Tx25 supported best the plant propagation. During the whole experimental process, the grass showed various growth tendencies. The best results for grass height were observed for mixes with textiles and colored newspaper. Based on this data and subsequent laboratory research, the best substrate composition was selected. For the whole period of the tests, germination rate in the pot with the mix was higher than the germination rate in the control sample with compost. Considering the experimental conditions of this research, the tested substrates can be used to aid in plant propagation, especially in regions with warm climate and soil deficiencies, and for restoration of damaged land areas.