Greenhouse Gas Emissions and Environmental Impact from Recycling the Organic Fraction of Solid Waste: Comparison of Different Treatment Schemes from a Life Cycle Perspective

The emission of greenhouse gases and the impact from recycling the organic fraction of solid waste were investigated from a life cycle (LCA) perspective. Three different treatment schemes were investigated with the aid of a pilot apparatus including exclusively composting (COMP), integrated solid anaerobic batch not inoculated and post-composting (SADBPC), and an integrated solid anaerobic batch inoculated and post-composting (SADBPC-I). SADBPC-I and SADBPC generated an average of 300 NL/kgVS and 267 NL/kgVS of biogas, respectively. On the other hand, the amount of stabilized organic carbon contained in the organic fertilizer returned by COMP, SADBPC-I, and SADBPC led to a potential of 470 kgCO2 eq/Mg, 382 kgCO2 eq/Mg, and 545 kgCO2 eq/Mg sequestered in soils for each treatment scheme, respectively. The LCA study highlighted that the impact categories most affected were global warming and human toxicity cancer, and on average, the highest impact was detected for COMP.