Comparative life cycle assessment of sewage sludge disposal options: Case study from the Republic of Serbia

The management of sewage sludge is a major environmental challenge in countries transitioning toward circular economy models. This study applies life cycle assessment (LCA) to compare three sludge disposal scenarios relevant to Serbia: unsanitary landfilling (S1), agricultural land application (S2), and incineration with energy recovery (S3), using the ReCiPe 2016 method and site-specific data. Results show that unsanitary landfilling is the least favorable option across all three aggregated endpoint categories due to methane emissions and long-term leachate, while incineration achieves the lowest impacts on human health and ecosystem quality, largely driven by energy recovery. Agricultural land application performs best in resource availability due to mineral fertilizer substitution but involves trade-offs related to ammonia emissions and metal-related toxicity. Sensitivity analysis indicates robust scenario ranking, with S2 strongly influenced by sludge nutrient content (especially nitrogen), and S3 by transport distance and DeNOₓ technology, leading to variations in resource availability of up to ±80% and +250%, respectively. Overall, avoided burdens from nutrient and energy recovery substantially reduce impacts, supporting a transition from landfilling toward recovery-oriented sludge management strategies in Serbia. • Life cycle assessment compared three sewage sludge disposal scenarios in Serbia. • Unsanitary landfilling caused the highest environmental and health burdens. • Agricultural reuse improved resource efficiency via nutrient substitution. • Incineration offered lowest damage through energy recovery credits. • Circular sludge management reduces impacts and supports sustainability goals.