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

Abstract

Abstract: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 kgCO 2 eq /Mg, 382 kgCO 2 eq /Mg, and 545 kgCO 2 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.

Agronomic and Environmental Performances of On-Farm Compost Production and Application in an Organic Vegetable Rotation

“…As observed in the EA, the analysis of the CO 2 emissions revealed that the total emissions generated by the on-farm composting were lower than those reported by more complex industrial composting technologies [53,55] and were comparable with the low technology/on-farm composting values reported [22,30,32] by Pergola et al [54], Pampuro et al [56] and Colon et al [57]. Moreover, in our study, the CO 2 fluxes that include the avoided emissions that would have occurred under green waste management, as well as the enhanced C sequestration from land application of compost, as described in other studies [26,58], were not evaluated. Considering a system boundary that includes these avoided emissions (landfill for green waste and enhanced C sequestration potential), they would have outweighed the sum of the direct and indirect emissions generated during the on-farm composting.…”

Effect Of Hydrothermal Pre-Treatment On Methane Production During Anaerobic Digestion Of Thickened Waste Activated Sludge

“…Due to methane usage in natural gas, which is often found in the production, refinement, and transformation as well as the storage of crude oil, therefore there is a significant risk of methane emission into the environment. (Sisani, 2017).…”

“…Surface mining releases about 1.9 grams of methane per kg of surface mined coal as well mining releases 4.23 grams of methane per kg of underground coal mined coal, as reported by the National Renewable Energy Laboratory. (Sisani, 2017).…”