Quantification of the water, energy and carbon footprints of wastewater treatment plants in China considering a water-energy nexus perspective

- We use footprint methodologies to quantify the water-energy nexus in WWTPs.
- A new indicator “gray water footprint reduction” is proposed.
- The energy intensity in most WWTPs is 0.4-0.5 kWh/m3 in China.
- 6.78 m3 gray water footprint is reduced when 1 m3 domestic sewage is treated.
- 0.28 kg CO2 are produced when electricity is used to treat 1 m3 domestic sewage.