Life-Cycle Inventory Analysis of Global Warming Impact of Sewage Sludge Recycling

To assess the global warming impact of sewage sludge recycling processes, Life-Cycle Inventory (LCI) analysis was applied to the scenarios of composting sludge, recycling sludge as a cement material, and sanitary landfill. In the analysis, the greenhouse gas emissions in these processes over the life cycle were calculated.In this case study, it was suggested that the global warming impact of recycling sludge as a cement material was the lowest, while the global warming impact of two sewage sludge recycling processes (composting sludge and recycling sludge as a cement material) was lower than that of sanitary landfill of dewatered or incinerated sludge. Therefore, shifting from sanitary landfill to sludge recycling processes is recommended from the viewpoint of mitigating global warming.