As night falls, citizens leisurely stroll in the park above the Qingshan Reclaimed Water Plant. At the same time, the gurgling clear stream undergoes layers of purification and flows into the Nanming River, quietly nourishing this mother river that has be

A meandering river with rippling blue waves, the Nanming River flows through the city and into the lives of the citizens of Guiyang. Riverside trails, urban parks, and internet famous street scenes are full of vitality for citizens to leisurely stroll, exercise, and keep fit. The first sunken reclaimed water plant in Guizhou, Qingshan Reclaimed Water Plant, is located in this vibrant area.

In 2014, there were only six sewage treatment plants in Guiyang city, with silt accumulation, black and odorous water bodies, and almost extinct fish... At that time, the urban population exceeded 3 million, and the sewage treatment capacity was seriously insufficient. That year, Nanming River was a "lifeless river". In the same year, Qingshan Reclaimed Water Plant, as the first sunken reclaimed water plant in Guizhou Province, started construction amidst the busy schedule and doubts from surrounding residents.

Liu Song, an engineer from the Guizhou business area of China Water Environment Group, said, "Construction started in early 2014 and water will be available by the end of the year. The construction period is tight. Nearby residents heard that a sewage treatment plant is going to be built at their doorstep, and they felt that it would have a smell and affect their lives. There are many voices opposing it." The governance is urgent, but the new sewage treatment plant faces many challenges such as difficult site selection and long construction period. For this purpose, they visited more than 200 households and explained door-to-door that the sunken reclaimed water plant is "silent and odorless", does not have any impact on the surrounding environment, and can return the ground to the people and the park to the people.

The reclaimed water plant adopts a 'fresh' multi-dimensional air constant purification system, which removes harmful gases collected from pre-treatment, biochemical treatment, and sludge treatment through microbial decomposition and activated carbon adsorption, achieving first-class exhaust emissions in the plant area, and almost no odor can be smelled in the plant, "said Cao Yonghui, the director of Qingshan Reclaimed Water Plant." Each treatment unit of the sunken water plant adopts a fully enclosed design, just like building the plant in a closed box and burying the entire box underground. "All equipment in the reclaimed water plant is underground and adopts noise reduction measures, which can achieve good sound insulation effect.

The purified water from Qingshan Reclaimed Water Plant flows into Nanming River. Yunnan Vocational College of Technology and Yao/Photo

The Qingshan Reclaimed Water Plant can treat 50000 tons of sewage per day, serving approximately 267000 people and covering an area of 10.86 square kilometers. The effluent quality shall comply with the Class A standard, with COD and ammonia nitrogen meeting the Class IV surface standard. If we build a traditional surface sewage plant, it would require an area of over 70 acres, but in reality, we only used 30 acres, saving nearly 40 acres of land, "Cao Yonghui said." More importantly, traditional surface sewage plants usually require a safety protection distance of 200-300 meters, while underground sewage plants do not need to set such a protection distance because there is no problem of odor and noise overflow, thus saving an additional 900 acres of isolation land

The upper part of Qingshan Reclaimed Water Plant has built a landscape park and the first water environment science popularization museum in the western region that is green, ecological, and low-carbon. The waterfront landscape belt built along the river has become a "popular check-in spot" for citizens' leisure and recreation, truly realizing the composite function of "land intensive, environmentally friendly, and resource reuse".

The Nanming River runs through the city. Yunnan Vocational College of Technology and Yao/Photo

The water treated by the reclaimed water plant maintains a temperature of 19-20 ℃ throughout the year. Water source heat pump technology is used to extract the tail water temperature (4-5 ℃), and the medium temperature is raised to 50 ℃ through compressors, heat transfer, etc. It is then transported to the surrounding urban buildings of the reclaimed water plant to provide centralized heating; When cooling, using end of pipe refrigeration equipment can lower the room temperature to about 21 ℃. The office building on the ground of our Qingshan factory uses this system, which provides heating in winter and cooling in summer, is environmentally friendly and energy-saving, "said Cao Yonghui." Recycled water is also used for municipal sanitation and ecological landscape water replenishment, realizing the recycling of water resources. "This successful practice of" one factory, multiple energy, one location, multiple uses "provides a replicable and promotable model for the management of the entire Nanming River basin. As of now, a total of 34 sewage treatment facilities have been established in the Nanming River Basin, of which 17 are designed in a sunken manner. The total daily processing capacity of sewage treatment facilities reaches 1.855 million tons, providing an average of about 450 million cubic meters of ecological water replenishment to Nanming River annually.

As night falls, citizens leisurely stroll in the park above the Qingshan Reclaimed Water Plant. At the same time, the gurgling clear stream undergoes layers of purification and flows into the Nanming River, quietly nourishing this mother river that has been reborn.