Denver Metro District: Quantifying Energy and Greenhouse Gas Mitigation Opportunities for Biosolids

Abstract

Opportunities for wastewater utilities to reduce primary energy use and greenhouse gas emissions are discussed and quantified based on an evaluation that included the Metro Wastewater Reclamation District (Metro District) Robert W. Hite Treatment Facility. Targeted GHG reduction tips for wastewater treatment plant (WWTP) operators are detailed focusing on water reuse and efficiency, energy efficiency and recovery, nutrient cycling, and infrastructure design for various greenhouse gas (GHG) inventory boundaries (i.e., Scope 1, 2, and 3), with emphasis on the impacts of biosolids processing. For WWTPs in general, biogas CHP, followed by co-firing digested solids, electricity efficiency, and avoided fertilizer represent the best ways for WWTPs to reduce their carbon footprint, respectively.

Life Cycle Energy Use and Greenhouse Gas Emission Analysis for a Water Resource Recovery Facility in India

“…The focus of these studies range from process specific to whole facility energy and GHG LCA. The only LCA study from the above group to use actual WRRF operating data was done by Pitterle for WRRFs in the United States (Rogowski et al, 2010;Pitterle, 2008). Typically, for these developed world studies, energy and electricity use in WRRF operations dominate life cycle GHG emissions, whereas GHGs embodied in infrastructure materials are lower, followed by process GHGs.…”