Pyrolysis of Sewage Sludge: Unlocking the Hidden Potential for Valorization and Carbon Sequestration

Sewage sludge management remains a critical environmental and economic challenge due to high volumes, transport requirements, and landfill restrictions.Pyrolysis offers a promising alternative by reducing sludge mass and producing biochar with potential for soil fertility enhancement and long-term carbon sequestration.This study integrates physicochemical characterization of Portuguese wastewater treatment plant sludges with experimental drying data and literature-based pyrolysis yields to estimate mass reduction, energy requirements, and carbon retention.A simplified life cycle comparison highlights potential reductions in greenhouse gas emissions, human toxicity, and land use, while also suggesting significant economic savings from avoided transport and landfill disposal.