| Abstract [eng] |
By adopting the Green Deal, the EU made a commitment to reduce its net greenhouse gas emissions (GHG) by at least 55 % by 2030 compared to 1990 levels and achieve climate neutrality in 2050. The aim of the study is to assess the possibilities of applying industrial ecology methods, reducing GHG, which are generated during biodegradable waste (BDW) management within Jonava district municipality. This study conducted an analysis of environmental legal acts and scientific literature to evaluate the potential for applying GHG reduction and industrial ecology methods in the field of BSA management. To assess the impact of the existing BDW control system on GWP, BDW flows and existing management practises in the Jonava district municipality were identified, it was evaluated that up to 4,400 tonnes of BDW are generated annually. The total impact of the existing BDW control system on GWP due to GHG is 731.5 t CO2e, incl. up to 92 % – due to GHG from open storage of sewage sludge in a polygone without biological treatment. After analysis of the results of GWP due to GHG caused by the BDW management, 4 problems were identified: improper “treatment” of sewage sludge, long BDW transportation distances, transportation and disposal of biofuel ash in a dumping site, unused potential of Industrial Symbiosis. To solve the problems, the paper proposes the development of BDW closed – loop control system, in which Industrial Ecology methods are applied: the creation of an Industrial Symbiosis between the companies of the Jonava district municipality that generate BDW (which would help to reduce transport distances and significantly reduce GWP due to the GHG), and the application of the principles of dematerialization (the efficient use of energy and material sludge). The study includes a feasibility analysis of an alternative to optimize the existing BDW management system, as well as an environmental and economic assessment. For the technical assessment of feasibility, a composting experiment was carried out at the sludge composting site of UAB "Jonavos vandenys", which demonstrated that, through applying the principles of Industrial Symbiosis, all BDW generated in the Jonava district could be aerobically treated together due to their nutritional properties and existing low contamination with heavy metals and impurities. Up to 2,200 tonnes of compost, a fertiliser product, could be produced annually for use in the municipality of purposes. As the sludge from the Jonava sewage treatment plant has a high concentration of total nitrogen (N), considerable attention was paid during the experiment to determine the mixing ratios of the different BDW streams to ensure the optimum C/N ratio for composting. The investment in upgrading (modernization) the existing sludge composting infrastructure would amount to 210 thousand Eur with a payback period of 5.4 years. The investigation has shown that the implementation of the proposed Industrial Ecology solutions in Jonava District Municipality would reduce GWP due to GHGs due to BDW management system by almost 85 % (from 731.5 to 111.9 tonnes CO2e per year). |
