Challenges in carbon footprint evaluations of state-of-the-art municipal wastewater resource recovery facilities

Autor: Maria Faragò, Anders Damgaard, Morten Rebsdorf, Per Henrik Nielsen, Martin Rygaard
Rok vydání: 2022
Předmět:
Zdroj: Faragó, M, Damgaard, A, Rebsdorf, M, Nielsen, P H & Rygaard, M 2022, ' Challenges in carbon footprint evaluations of state-of-the-art municipal wastewater resource recovery facilities ', Journal of Environmental Management, vol. 320, 115715 . https://doi.org/10.1016/j.jenvman.2022.115715
ISSN: 1095-8630
DOI: 10.1016/j.jenvman.2022.115715
Popis: Wastewater treatment is an important source of direct and indirect greenhouse gas (GHG) emissions, which some wastewater operators report and account for CO2-eq impacts through carbon footprint evaluations. We investigated the challenges with GHG emissions’ accounting of three state-of-the-art energy-efficient wastewater resource recovery facilities (WRRFs) and reviewed their CO2 accounting reports. Our study aimed to highlight the major contributors and factors to estimate emissions, including direct N2O and CH4 emissions and propose recommendations for public reporting of CO2 accounting of WRRFs. We categorised emissions as direct (scope 1), background (scope 2), downstream and avoided emissions (scope 3A and 3B) and evaluated how a change in emission factor may affect how close the WRRFs are to reaching CO2 neutrality. The results show that electricity consumption and direct emissions constitute between 20 and 70% of actual CO2-eq emissions and therefore need careful consideration.All three plants have increasingly offset scope 2 emissions over 2014–2019, resulting in a total reduction of approximately 3211 tons CO2-eq, corresponding to 72% of their needed cuts by 2030 set by the Danish government.No standard factors are used across the plants to estimate emissions. We propose some general recommendations that wastewater operators can apply to correctly report and account for CO2-eq emissions. We also recommend that operators move their long-term focus from CO2 neutrality to CO2-eq reduction and make an effort to measure and quantify scope 1 direct emissions properly. A tax on N2O emissions should be introduced in future policies.
Databáze: OpenAIRE
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