The journey of a bag of household trash becomes even more revealing. Trucks first descend to an unloading platform eight meters underground. Waste is then stored in a bunker reaching 23 meters below ground, where it is left for about seven to 10 days before the huge crane grabs mix it and feed it into incinerators. There, temperatures exceed 900 C.

　　A technician at the waste treatment plant monitors the flames inside the incinerator, where the flame temperature exceeds 900 C. Photo: Li Hao/GT

　　The heat produces steam, which drives turbines to generate electricity. Part of that power is consumed by the park itself, while the remainder is fed into the grid. Zhang said the facility can save roughly 70,000 tons of standard coal.

　　Even the material left after burning is given another life. Bottom ash is processed into recycled aggregate that can be used in municipal construction and road building. Residues from food waste, sludge and medical-waste treatment can be sent for incineration, while biogas produced in related processes is reused as supplementary fuel.

　　Flue gas generated during incineration undergoes multi-stage purification before being discharged up to standard, Zhang told the Global Times. The plant"s emission standards are stricter than both national and EU benchmarks. For instance, its dioxin emission concentration is only half of the limits set by China and the EU. All residual waste from the treatment of kitchen waste, sludge and medical waste is also sent to incinerators for harmless disposal.

　　In a sense, the facility functions like the city"s "stomach," taking in different kinds of waste, treating them safely, and turning what it can into useful resources.

　　In the central digital control room, this circular system is translated into numbers.