Revisiting China's domestic greenhouse gas emission from wastewater treatment: A quantitative process life-cycle assessment

Dengting Guo; Bing Li; Wei Yu; Jing-Cheng Han; Yang Zhou; Zhilong Ye; Xiaofeng Wu; Brent Young; Yuefei Huang

doi:10.1016/j.scitotenv.2023.162597

Revisiting China's domestic greenhouse gas emission from wastewater treatment: A quantitative process life-cycle assessment

Sci Total Environ. 2023 Jun 10:876:162597. doi: 10.1016/j.scitotenv.2023.162597. Epub 2023 Mar 5.

Authors

Dengting Guo¹, Bing Li², Wei Yu³, Jing-Cheng Han⁴, Yang Zhou⁴, Zhilong Ye⁵, Xiaofeng Wu⁶, Brent Young³, Yuefei Huang⁷

Affiliations

¹ Water Research Center, Tsinghua Shenzhen International Graduate School, Tsinghua, Shenzhen 518055, China; Department of Chemical & Materials Engineering, University of Auckland, 0926, New Zealand.
² Water Research Center, Tsinghua Shenzhen International Graduate School, Tsinghua, Shenzhen 518055, China. Electronic address: [email protected].
³ Department of Chemical & Materials Engineering, University of Auckland, 0926, New Zealand.
⁴ Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
⁵ Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
⁶ Water Research Center, Tsinghua Shenzhen International Graduate School, Tsinghua, Shenzhen 518055, China.
⁷ Water Research Center, Tsinghua Shenzhen International Graduate School, Tsinghua, Shenzhen 518055, China; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, Qinghai 810016, China.

PMID: 36871740
DOI: 10.1016/j.scitotenv.2023.162597

Abstract

The wastewater treatment industry could alleviate water pollution but consume a large amount of energy and resources. China has over 5000 centralized domestic wastewater treatment plants and produces an unignorable amount of greenhouse gases (GHG). By considering the wastewater treatment, wastewater discharge, and sludge disposal processes, and employing the modified process-based quantification method, this study quantifies wastewater treatment's on-site and off-site GHG emissions across China. Results showed that the total GHG emission was 67.07 Mt CO₂-eq in 2017, with approximately 57% of on-site emissions. The top seven cosmopolis and metropolis (top 1%) emitted nearly 20% of the total GHG emission, while their emission intensity was relatively low due to the huge population. This means that a high urbanization rate may be a feasible way to mitigate GHG emissions in the wastewater treatment industry in the future. Furthermore, GHG reduction strategies can also focus on process optimization and improvement at WWTPs as well as the nationwide promotion of onsite thermal conversion technologies for sludge management.

Keywords: Greenhouse gas emission; Process life-cycle assessment; Sludge management; Wastewater treatment.