Carbon emission accounting， influencing factors， and carbon reduction pathways in typical A<sup>2</sup>/O process municipal wastewater treatment plants

ZHENG Xiaoying; HU Tianxing; DENG Xiongcheng; TAO Jiaqing; GONG Yiping; YAO Xinyu; FAN Yi; LIN Tao; CHEN Wei; WANG Dawei

doi:10.13205/j.hjgc.202603016

Volume 44 Issue 3

Mar. 2026

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Article Navigation > ENVIRONMENTAL ENGINEERING > 2026 > 44(3): 177-188

ZHENG Xiaoying, HU Tianxing, DENG Xiongcheng, TAO Jiaqing, GONG Yiping, YAO Xinyu, FAN Yi, LIN Tao, CHEN Wei, WANG Dawei. Carbon emission accounting， influencing factors， and carbon reduction pathways in typical A2/O process municipal wastewater treatment plants[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 177-188. doi: 10.13205/j.hjgc.202603016

Citation:

ZHENG Xiaoying, HU Tianxing, DENG Xiongcheng, TAO Jiaqing, GONG Yiping, YAO Xinyu, FAN Yi, LIN Tao, CHEN Wei, WANG Dawei. Carbon emission accounting， influencing factors， and carbon reduction pathways in typical A²/O process municipal wastewater treatment plants[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 177-188. doi: 10.13205/j.hjgc.202603016

Citation:

ZHENG Xiaoying, HU Tianxing, DENG Xiongcheng, TAO Jiaqing, GONG Yiping, YAO Xinyu, FAN Yi, LIN Tao, CHEN Wei, WANG Dawei. Carbon emission accounting， influencing factors， and carbon reduction pathways in typical A²/O process municipal wastewater treatment plants[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 177-188. doi: 10.13205/j.hjgc.202603016

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Carbon emission accounting， influencing factors， and carbon reduction pathways in typical A²/O process municipal wastewater treatment plants

doi: 10.13205/j.hjgc.202603016

1. Key Laboratory of Comprehensive Management and Resource Development of Shallow Lakes，Ministry of Education，School of Environment，Hohai University，Nanjing 210098，China;
2. Suzhou Water Authority，Suzhou 215011，China;
3. Suzhou Water Supply and Drainage Management Office，Suzhou 215004，China

Received Date: 2025-07-13
Available Online: 2026-04-11
Publish Date: 2026-03-01

Abstract

Abstract

Under the context of global warming， it is imperative to advance the synergistic efficiency of pollution reduction and carbon mitigation in the wastewater treatment industry. This study is based on the 2023 operational data from three typical municipal wastewater treatment plants （WWTPs） in Jiangsu Province employing A²/O and its modified processes. Using the emission factor method， carbon emission accounting and characteristic analysis were conducted. and explored the impact of influent characteristics and operational parameters on the carbon emissions of WWTPs through path analysis. From an indirect control perspective， this study assessed the carbon reduction potential of measures such as photovoltaic power generation and water-source heat pumps. The results indicate that： The total carbon emission intensity of the three typical WWTPs ranged from 0.578 kg/m³ to 0.671 kg/m³， with total carbon emissions between 18890 t and 28150 t. The indirect carbon emissions account for a relatively high proportion （71.7%） of the total carbon emissions in A²/O wastewater treatment plant， with electricity consumption contributing the most （53.3%） to the carbon emissions. The carbon emissions attributed to carbon source dosage accounted for the largest proportion of chemical consumption， reaching 36.9% to 59.5% of the total chemical carbon emissions. The operation of wastewater treatment plants with lower influent concentrations requires higher energy and material consumption， resulting in greater indirect carbon emissions. Furthermore， the influent water quality characteristics and operational parameters of typical A²/O process wastewater treatment plants all have direct or indirect impacts on various types of carbon emission intensities. To effectively control carbon emissions， plants can actively optimize process operational parameter adjustments， implement equipment upgrades and retrofits， adopt intelligent/smart control systems， and implement various carbon-alternative measures. By adopting PV power generation and water-source heat pumps， WWTP2 could theoretically achieve 22.7% and 100.2% carbon displacement rates， respectively， demonstrating significant carbon reduction potential.
- wastewater treatment plant,
- A²/O,
- carbon accounting,
- path analysis,
- carbon reduction

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References(55)

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