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Sustainable Use of Organic Matter Obtained from the Bottom of a Post-Mining Pit Reservoir—A Case Study on the Creation of Raduszyn Lake in Poland
According to historical sources, a watermill existed in the valley of the Trojanka River on the north-western shore of Raduszyn Lake from the 15th century. Its dams lasted for centuries causing the water flow through the Raduszyn reservoir to slow down and deposit various mineral fractions in it. The aim of paper was to develop a scientific background for the sustainable management of organic matter extracted from the peat top and from deeper layers that are unsuitable for direct use, that is, decomposed peat. A SWOT (strengths, weaknesses, opportunities, threats) analysis was used to describe ways of restoration of the water reservoir alongside the characterization of organic matter and the financial condition of the studied enterprise. For the use of the studied material as a homogeneous substrate for plant cultivation, the contents of nitrogen, phosphorus, potassium, and copper were insufficient, whilst calcium was excessive. Microbiological analyses of the organic materials intended as an additive for horticultural substrates confirmed the presence of plant growth-promoting bacteria. The occurrence of such microorganisms in the substrate can limit the use of mineral fertilizers and chemical plant protection products. The results of the research can be an example for enterprises restoring or creating water reservoirs by extraction of organic matter, which is often considered as waste that generates costs and does not bring financial benefits. Such a measure can be used to improve the efficiency of water reservoir restoration enterprises and at the same time contribute to sustainable land development.
Analysis of the impact of road noise on urban green spaces: a case study of the dendrological garden in Poznań, Poland
Abstract Green parks and gardens in urban areas are an essential part of ecosystem services for inhabitants, especially in cities where people are affected by road noise. These problems have been the subject of many studies worldwide. Such works have been carried out at many levels—both in the contexts of spatial planning and ecological analyses. In relation to this, the design of noise maps and related spatial modelling is significant. The paper presents the results of a survey of the acoustic environment in the Dendrological Garden in Poznań—the fifth largest city in Poland—which is a vital part of the city’s green zone. The analysis of the noise distribution across the park’s zones was carried out at frequent intervals using sound-level surveys during 2014 and 2020. Moreover, acoustic maps developed for Poznań in 2012 and 2017 were compared with these recent studies. The changes (gain or loss) in those areas with a particular noise level are based on the area variability index.
Recent Issues and Challenges in the Study of Inland Waters
This paper addresses several important problems and methods related to studies of inland waters based on the existing scientific literature. The use of UAVs in freshwater monitoring is described, including recent contact and non-contact solutions. Due to a decline in biological diversity in many parts of the globe, the main threats are described together with a modern method for algae and cyanobacteria monitoring utilizing chlorophyll a fluorescence. Observed disturbances in the functioning of river biocenoses related to mine waters’ discharge, causing changes in the physico-chemical parameters of waters and sediments, give rise to the need to develop more accurate methods for the assessment of this phenomenon. Important problems occurring in the context of microplastic detection, including the lack of unification, standardization and repeatability of the methods used, were described. In conclusion, accurate results in the monitoring of water quality parameters of inland waters can be achieved by combining modern methods and using non-contact solutions.
Financial Security as a Basis for the Sustainable Development of Small and Medium-Sized Renewable Energy Companies—A Polish Perspective
In conditions of economic and political instability, when unpredictability affects business, the need for security, including financial security, becomes particularly important. In our study, we address this issue, with the main objective of comparing and evaluating the financial security of small and medium-sized renewable energy companies in Poland according to sustainable development goals. In order to study and describe relationships between selected groups of companies, financial ratios were used, including canonical variate analysis. The liquidity ratios of the surveyed companies indicated a low level of financial security in terms of the ability to meet short-term liabilities. The profitability of operations was low and did not contribute to the improvement of financial security in most of the companies. The lowest return on assets was found in the group of biogas plants. Higher profitability of assets was found in solar power plants, including those with system installations. Solar power plants were also characterized by a high level of total debt and a rapid turnover of assets in comparison to other studied companies. The results show that the financial security of small and medium-sized renewable energy enterprises in Poland is low, which may be a threat to sustainable development in the future.
Functioning of the Energy Sector Under Crisis Conditions—A Polish Perspective
In the context of the coronavirus pandemic and the armed conflict between Russia and Ukraine, energy security is essential to economic challenges nowadays. The basis for the proper operating of the energy sector is to ensure a stable supply of energy to end users and to secure finances of energy companies, so that they can operate sustainably in times of uncertainty. In our studies, we have addressed this issue with the main objective of assessing the state of energy security from the perspective of the stability of the financial situation of energy sector companies in the context of the global energy crisis and a sustainable energy future. Financial indicators and a canonical variable analysis were used to examine the financial situation of companies in the energy sector and to describe links between selected groups of energy companies. Such companies operating during political and economic instability did not record worse financial results than in the year 2018. It was found that in case-studied firms, total debt decreased and moreover, liquidity and return on assets improved. Companies have focused on securing their financial health and ensuring the stability of their energy supplies and the issue of the environmental impact of energy production has unfortunately become a secondary concern. Nevertheless, in the event of further crises, it is reasonable to assume that a focus on maintaining liquidity and generating profits for energy companies will be more important to companies than environmental challenges and the fight against climate change.