Carbon Emissions from Sludge Treatment in a Sewage Treatment Plant: Field Study Investigation in Guangzhou, China
Publication: Journal of Environmental Engineering
Volume 150, Issue 12
Abstract
The treatment of sludge is one of the main sources of carbon emissions throughout the entire life cycle of sewage treatment. This study conducted carbon emission analysis on the sludge treatment process of a sewage treatment plant in Guangzhou, China, and offered a carbon accounting boundary calculation process for the sludge called the deep dehydration–drying–incineration process. An international standard method was improved to offer a carbon emissions accounting method for direct carbon emissions, indirect carbon emissions, and carbon sink for the sludge treatment of the effluent treatment plant. Research has found that the amount of sludge treatment is directly proportional to carbon emissions and carbon sinks. When the sludge treatment capacity reaches 600 t or more, almost zero carbon emissions are achieved, and the carbon emissions generated during the incineration stage of sludge treatment are the highest in all process steps. In addition, there is a significant positive correlation between dry sludge treatment capacity and carbon emissions from drying/integration. There is a significant positive correlation between dry sludge treatment capacity and direct emissions caused by incineration, but there is no correlation with carbon emissions generated by the use of electricity/chemicals. This study offered important data support and technical reference for the resource development and low-carbon disposal regulation of sludge, and a basis for the calculation of carbon emissions throughout the entire process of sludge treatment.
Practical Applications
The paper explored the carbon emission accounting method for sludge treatment. An international standard method has been improved to offer an accounting method for direct carbon emissions, indirect carbon emissions, and carbon sequestration of sludge treatment in sewage treatment plants, providing possibilities for carbon accounting throughout the entire life cycle of sewage and sludge in sewage treatment plants. The results show that the sludge treatment capacity is directly proportional to carbon emissions and carbon sinks. When the sludge treatment capacity reaches 600 t or more, almost zero carbon emissions are achieved, and the carbon emissions generated during the sludge treatment incineration stage are the highest in all process steps. In addition, there is a significant positive correlation between dry sludge treatment capacity and carbon emissions from drying/integration. There is a significant positive correlation between dry sludge treatment capacity and direct emissions caused by incineration, but there is no correlation with carbon emissions generated by the use of electricity/chemicals. The research results contribute to the resource utilization and low-carbon disposal of sludge.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
The authors also would like to thank the project of Establishment of Carbon Emission Accounting Standards and Methodology for Guangzhou’s Sewage Industry (10492022000002). This research is financially supported by the project of Establishment of Carbon Emission Accounting Standards and Methodology for Guangzhou’s Sewage Industry (10492022000002).
Authors contributions: Yaning Wang: Conceptualization; Investigation; Methodology; Data curation; Writing–original draft; Writing–review and editing; Visualization; Supervision. Dong Luo: Conceptualization; Investigation; Methodology; Data curation; Writing–review and editing; Visualization; Supervision; Translation.
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Published In
Journal of Environmental Engineering
Volume 150 • Issue 12 • December 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Dec 4, 2023
Accepted: Jun 26, 2024
Published online: Sep 26, 2024
Published in print: Dec 1, 2024
Discussion open until: Feb 26, 2025
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