Recent interest in greenhouse gas (GHG) emissions has driven the need to better quantify such emissions from waste management processes. The Biosolids Emissions Assessment Model (BEAM) is a tool that quantifies GHG emissions in biosolids management. The objective of this study was to determine the validity of the BEAM, by estimating and assessing GHG emissions for selected biosolids management practices. An Alberta, Canada-based facility that currently treats biosolids was selected as a case study. Six different end-use strategies within the Alberta region were assessed and compared: lagoon storage, land application, composting, biosolids cake storage, thermal energy, and landfill disposal. Based on the model results, the order of emissions (from least to highest) is: land application < lagoon storage < biosolids cake storage < composting < thermal energy < landfill disposal. These results may not be entirely accurate, as estimates were used for input parameters instead of site-specific data and certain parameters in the BEAM, such as soil sequestration factor for compost, may not reflect real conditions. In addition, a conservative approach was taken for the lagoon storage emissions calculations. The BEAM may provide a good means for municipalities to determine GHG emissions, but in order to obtain more accurate emissions estimates for various biosolids management practices, on-site measurements and further model assessments are required.
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