The purification journey of a drop of sewage

In early summer, on Guangyang Island in Chongqing, fish play in the gurgling stream and dragonflies dance among the numerous flowers.

This is the largest eco-island in the middle of the Yangtze River in terms of area. Before the Yangtze River was protected, over-development led to serious ecological deterioration. Today, a Bayu pastoral landscape painting is slowly unfolding on Guangyang Island.

*** Focus on large-scale protection, not large-scale development. In recent years, focusing on the main theme of ecological priority and green development, many cities along the Yangtze River have explored urban smart water stewards, launched a battle against pipe networks, and transformed sewage treatment plants into resource factories to innovate urban sewage treatment. The latest data from the Ministry of Ecology and Environment show that the state-controlled section of the main stream of the Yangtze River has reached Class II water quality for three consecutive years. The mother river of the Yangtze River is full of vitality.

In the past few days, reporters have traveled down the Yangtze River and visited relevant provinces and cities, and experienced the scientific and technological content of the Yangtze River Protection through the purification journey of a drop of sewage.

In Lu'an, Anhui, at the centralized control center of Lu'an Water Steward Company of Yangtze River Environmental Protection Group, a subsidiary of China Three Gorges Corporation, the constantly beating data on the large screen of the smart control system marks the "journey" of a drop of sewage in the city——

Whenever water consumption increases during holidays, the "Water Steward" issues water diversion instructions and summons nearby water plants for "reinforcement" to ease the water supply pressure; at the same time, the "Water Steward" estimates the drainage volume based on water consumption. If it exceeds The sewage treatment capacity of the area will direct the sewage to other sewage treatment plants to ensure the healthy "metabolism" of the city. In the event of rainfall, the "Water Steward" will quickly generate a precipitation model, predict the areas most likely to accumulate water based on the direction of surface water, make plans in advance, turn on the corresponding drainage pumps, and "unscrew" the drainage valves of rivers in the city to free up storage capacity and avoid waterlogging. .

“We learn from the way we manage the power system to manage urban sewage, and use ‘one network’ to promote the city’s integration of supply and drainage, factory-factory linkage, and factory-network linkage to reconstruct the urban water system and transform into fragmented governance. In order to coordinate precise water control," said Huang Rongmin, executive general manager of the Anhui Regional Company of Yangtze River Environmental Protection Group.

As of April, Lu'an has built more than 100 kilometers of rainwater and sewage pipe networks, and completed the renovation of rainwater and sewage diversion in 111 residential areas. The water environment is undergoing turning changes - in three years, the centralized collection rate of urban domestic sewage has increased from 44.8 increased to 67.72; sewage treatment capacity increased from 185,000 tons/day to 415,000 tons/day; 14 black and odorous water bodies have all been remediated and passed review and cancellation by the Ministry of Housing and Urban-Rural Development, and 22 waterlogging points have been remediated.

In view of the problems existing in cities along the Yangtze River such as low sewage collection rate, backward pipe network and other infrastructure, inefficient operation of sewage treatment plants, separation of factories and networks, and "fragmentation and fragmentation" of the industrial chain, "We We have signed 'Water Steward' cooperation agreements with 23 cities and counties along the Yangtze River, and have registered 'Water Steward' companies in Lu'an, Yueyang, Yichang, Xiantao, Jiujiang, Wuhu and other places, with the goal of 'one city, one blueprint, One mechanism, one steward, to restore the ecology and protect the environment from the source," said Wang Dianchang, Secretary of the Party Committee and Chairman of the Yangtze River Environmental Protection Group.

Pollution is in the water, its source is on the shore, and the key lies in the pipe network. Only when the pipeline network is healthy can rivers and lakes be healthy. Qu Jiuhui, an academician of the Chinese Academy of Engineering, said that the pipe network is the artery of the city, an important infrastructure and "lifeline" for the operation of the city, and it is also a key link and prominent issue in improving the quality and efficiency of urban sewage treatment. Systematic pollution control thinking is the focus of the government’s efforts to protect the Yangtze River.

We targeted the pipe network, a shortcoming in urban sewage treatment, to implement comprehensive management of the urban water environment focusing on the pipe network, and used 70 Yangtze River protection-related investments in the construction of factory networks. "Wang Dianchang said.

Every drop of sewage flows into the sewage treatment plant, where it transforms turbidity into clean water.

In the suburbs of Yixing on the lower reaches of the Yangtze River, there is a complex of avant-garde designed buildings , green plants and flowers cover the small pond and cafe, the air is fresh, the birds are singing and the flowers are fragrant. From time to time, citizens come here for a walk. This is not a city park but my country's first urban sewage resource concept plant.

“We are trying to reinterpret the relationship between sewage plants and cities, expanding the traditional sewage treatment plant from the basic function of reducing pollutants to various application scenarios such as urban energy, water sources, fertilizer plants, etc., conveying that 'sewage is a resource' "The concept of sewage treatment plant is a resource factory, which integrates ecology, life and production, eliminates the 'NIMBY effect', and creates a new urban space that is open and enjoyable," Zhang Yifei, chairman of Zhongchi Water Co., Ltd., introduced. Open a bottle of "sustainable water" produced by the water factory to quench your thirst.

Sustainable water quality, energy self-sufficiency, resource recycling, and environmental friendliness." Yixing Concept Water Plant explains this operational goal with a set of data - producing 20,000 cubic meters of recycled water and 8,000 cubic meters of biogas every day , 23 tons of organic fertilizer, and 18,000 kilowatt-hours of electricity. At the same time, the dried biogas residue is used for landscaping and brick-making soil, demonstrating the "water magic" of turning sewage into resources and sludge into a sea of ??flowers.

“The sewage treatment plant is also a laboratory. It has a 20,000-ton/day water purification center, a 100-ton/day organic matter collaborative processing center, and a production-oriented R&D center. Here, cutting-edge technologies from the laboratory can also be directly applied to real-life scenarios to promote the transformation of scientific and technological achievements. " said Li Ji, a professor at the School of Environmental and Civil Engineering of Jiangnan University, one of the members of the Yixing Concept Water Plant Expert Committee.

Currently, the Three Gorges Group has participated in the comprehensive protection of the Yangtze River and has completed a total investment of approximately 95 billion yuan. , a total of 325 sewage plants have been put into operation, with a sewage treatment capacity of 4.26 million cubic meters per day, and a pipeline network length of 18,000 kilometers under construction and operation. Black and odorous water bodies within the cooperation scope of the pilot cities have been completely eliminated, and outstanding ecological and environmental problems in the cooperation area have been basically eliminated. .