Life cycle assessment of deploying sludge minimization with (sulfidogenic-) oxic-settling-anaerobic configurations in sewage-sludge management systems

This study conducted life-cycle evaluation (on the greenhouse gas (GHG) emissions, energy consumption and economic performance) and sensitivity analysis in nine scenarios considering the deployment of conventional anoxic/oxic (AO) and/or sludge-minimizing (OSA, SOSA) bioprocess for sewage treatment linking with subsequent sludge handling. The analysis results demonstrated that compared with conventional AO-based scenarios, OSA- and SOSA-based scenarios reduced 23-28% GHG emissions (GHGs) and 18-24% cost, despite no significant electricity consumption reduction. The scenario analysis indicates renewable energy and improving energy consumption efficiency benefit the application of OSA and SOSA. The perturbation analysis revealed that the influential factors related to energy consumption were sensitive to GHGs, energy consumption and economic effects.