Municipal wastewater treatment plays an indispensable role in enhancing water quality by eliminating contaminants. While the process is vital, its environmental footprint, especially in terms of greenhouse gas (GHG) emissions, remains underexplored. Here we offer a comprehensive assessment of GHG emissions from wastewater treatment plants (WWTPs) across China. Our analyses reveal an estimated 1.54 (0.92–2.65) × 10⁴ Gg release of GHGs (CO₂-eq) in 2020, with a dominant contribution from N₂O emissions and electricity consumption. We can foresee a 60–65% reduction potential in GHG emissions with promising advancements in wastewater treatment, such as cutting-edge biological techniques, intelligent wastewater strategies, and a shift towards renewable energy sources.

The substrate modified by GO could greatly improve water flux, whereas the GO-functionalized active layer is favorable for biofouling mitigation.