From House to Farm: Life Cycle Assessment of Sewage Sludge as a Circular Fertiliser at Regional European Level

This study evaluates the environmental performance of stabilised sewage sludge used as a circular fertiliser across three European regions: Central, Mediterranean, and Northern Europe, comparing its performance against non-renewable fertilisers. The research applies a life cycle assessment approach, considering a mix of the most used stabilisation technologies in each region, such as anaerobic digestion, chemical treatment, thermal drying, composting, and aerobic digestion. Environmental impacts were assessed based on key categories, including climate change, acidification, eutrophication, and resource use. The environmental performance of circular fertiliser production outperformed non-renewable fertilisers in all assessed categories, showcasing its potential as a sustainable alternative. Findings reveal that the choice of stabilisation process is key to the overall environmental performance of the region. High energy-driven technologies such as thermal drying present the bigger impacts. Regional disparities highlight the need for context-specific technology selection to optimise environmental outcomes. The study underscores the importance of integrating energy recovery and nutrient recycling in sludge management practices. These findings advocate for the promotion of circular fertilisers within a sustainable agricultural framework, emphasising technology adaptation based on local conditions to enhance ecological and economic benefits.