Greenhouse gas emissions associated with urban water infrastructure: What we have learnt from China's practice

Abstract

Municipal water and wastewater services have complicated sources of greenhouse gas (GHG) emissions, and quantifying their roles is critical for tackling global environmental challenges. In this study we provide a systematic review of the state‐of‐the‐art on GHG emission characterizations of China's urban water infrastructure with the aim of shedding light on global implications for sustainable development. We started by synthesizing a framework on GHG emissions associated with water and wastewater infrastructure. Then we analyzed the different sources of GHG emissions in drinking water and wastewater treatment systems. In drinking water services, electricity consumption is the largest source of GHG emissions. A particular concern in China is the common use of secondary pumping for high‐rise buildings. Optimized pressure management with an efficient pumping system should be prioritized. In wastewater services, non‐CO2 emissions such as methane (CH4) and nitrous oxide (N2O) emissions are substantial, but vary greatly depending on regional and technological differences. Further research directions may include GHG inventory development for urban water systems at the plant level, quantifications of GHG emissions from sewer systems, emission reduction measures via water reclamation, renewable energy recovery, energy efficiency improvement, cost–benefit analyses, and characterizations of Scope 3 emissions. This article is categorized under: Engineering Water > Sustainable Engineering of Water Science of Water > Water and Environmental Change Engineering Water > Planning Water

Investigating high methane emissions from urban areas detected by TROPOMI and their association with untreated wastewater

“…In the global wastewater database, 65% of wastewater produced in China was collected, and 100% of that was treated. One of the particularities of China is the extensive pretreatment of wastewater due to tight controls on pollutant discharges to municipal sewers [48]. Although the pretreatment of wastewater has been hypothesized to lead to extra methane emissions, we do not see a signature in the TROPOMI retrievals.…”

Mitigating greenhouse gas emissions from municipal wastewater treatment in China

“…Urban wastewater systems are a complex source of GHG emissions, characterized by intricate interactions between water and energy [ [9] , [10] , [11] ]. Recognizing the urban water sector's role in GHG emissions is imperative for addressing the challenges posed by global warming [ 6 , 12 ]. GHG emissions from wastewater treatments are primarily derived from direct productions (e.g., N 2 O and CH 4 ) and indirect CO 2 emissions from energy and chemical consumptions [ 13 ].…”

Water, Energy, and Emissions Nexus: Effect of Inflows in Urban Drainage Systems

“…The GHG emissions associated with energy consumption in the wastewater sector are substantial. Direct and indirect GHG emissions integrate CO 2 emissions related to energy consumption and others not linked to energy consumption, such as methane (CH 4 ) and nitrous oxide (N 2 O) emissions, mainly in wastewater systems [8,15,[23][24][25]. Specific data on the water, energy, and emissions nexus in the sector, reported for individual regions or countries, can be found in the literature e.g., [1,8,9,17,24].…”