Recycling of Sewage Sludge in Poland – Environmental Aspects and Risks Related to Its Management in a Circular Economy

Abstract

Sewage sludge generated in the process of household and industrial wastewater treatment plants should be utilized in line with the principles of sustainable development, taking into account the processes that are an inherent part of the circular economy. The research conducted for this paper has shown that, on average, in Poland between 2019 and 2023, over a million sewage sludge deposits were created; 57% of these were household and 43% were industrial sewage sludge. The generated sewage sludge is processed in four major processes, covering its use: in agriculture (56.09%), thermal processing (20.62%), storage (17.5%), and compost production (4.72%). The analysis of technical and environmental aspects has demonstrated that the available technologies are sufficient to utilize sewage sludge in accordance with the principle of a circular economy, utilizing state-of-the-art technologies. On the other hand, the heavy metals contained in sewage sludge pose a potential threat to human health if the sludge is not properly managed and safety rules are not adhered to in waste management. The research results form a basis for discussion, focusing on both the quality and quantity aspects, leading to the optimization of methods for utilizing sewage sludge in thermal, organic, or material recycling processes to increase the recycling rate of sewage sludge in Poland