Sewage treatment has always been an environmental issue of great concern to the government and society. In recent years, driven by national industrial policies and market demand, the sewage treatment industry has advanced by leaps and bounds. The overall development is in a rapid growth period. The sewage treatment capacity has expanded rapidly, the sewage treatment rate has steadily increased, and the sewage treatment volume has increased rapidly. However, it also faces sewage treatment plants. Problems such as upgrading of standards, old pipe networks, and substandard water quality.

In this regard, people in the industry believe that the sewage treatment industry should accelerate the completion of shortcomings, and promote the industry's transformation from scale growth to quality and efficiency.

Intensive introduction of multiple policies

In order to speed up the development of the "short board" of the sewage treatment industry, policies on improving the quality and efficiency of sewage treatment have been intensively introduced.

In early April, the Sichuan Provincial Department of Ecology and Environment and other eight departments jointly issued the "Three-year Promotion Plan for Rural Domestic Sewage Treatment in Sichuan Province", which proposed that by the end of 2020, more than 50% of domestic sewage in administrative villages in Sichuan Province will be effectively treated and treated. The rate and utilization rate of resources have been significantly increased, and the phenomenon of disorderly discharge of domestic sewage has been significantly reduced; by the end of 2021, more than 60% of domestic sewage in administrative villages in Sichuan Province has been effectively treated, and the phenomenon of disorderly discharge of domestic sewage has been effectively controlled; by 2022 By the end of the year, strive to effectively treat more than 65% of domestic sewage in administrative villages in Sichuan Province, and improve the quality of the rural human settlement environment, and embark on the road of rural sewage treatment with Sichuan characteristics.

On April 20, it was learned from the Promotion Conference on Quality Improvement and Efficiency of Urban Sewage Treatment in Zhejiang Province that Hangzhou Province will build 67 urban sewage treatment plants by 2020-2021, with a daily treatment capacity of more than 3 million tons , Completed 104 urban sewage treatment plant clean discharge technical transformation, newly constructed and reconstructed sewage pipe network more than 2,300 kilometers.

On April 21, the Hubei Provincial Department of Housing and Urban-Rural Development issued the "Hubei Province Urban Sewage Treatment Quality and Efficiency Improvement Action Plan" proposed that by 2021, Hubei Province, cities above the prefecture-level cities basically have no direct sewage discharge, basically eliminated In the urban villages, old urban areas and urban-rural junctions, the domestic sewage collection and treatment facilities are in the blank area, and the efficiency of centralized collection of urban sewage is significantly improved.

Prior to this, provinces such as Anhui, Jiangsu, Gansu, and Jilin also successively issued relevant policies and plans for sewage treatment to improve quality and increase efficiency. Industry insiders believe that with the continuous implementation of local policies, the sewage treatment industry will be accelerated to improve quality and efficiency. At the same time, it will also increase the scale of the sewage treatment market.

Sewage treatment "pain" on the pipe network

"The problem is in the water, the roots are on the shore, and the core is in the pipe network." This has become a general consensus reached in the industry. People in the industry believe that the upgrading of the pipeline network is a key part of the sewage treatment industry to improve quality and efficiency. "If the pipeline network is not treated, everything is in vain."

"The invisible pipe network that has been buried in the ground, its'pain points' have gradually emerged in recent years." Jing Yuanyuan, head of the E20 Environmental Platform Water Industry Research Center and chief industry analyst, said: "Due to a long period of time in the past, We generally pay attention to the construction of sewage treatment plants, and ignore the construction of pipeline networks, the phenomenon of'heavy plant light network' is serious. At the same time, the planning and design of the pipeline network is not scientific, the construction is not standardized, and the quality of the materials is uneven, resulting in pipeline damage and sewage. Problems such as extravasation, and a large gap in funding requirements for repairs. Therefore, it is difficult to pay off the debt of the pipeline network in a short time."

"Through the construction of the pipe network, the pollutants are sent to the sewage treatment plant, rather than just the water to the sewage treatment plant." Zhang Chen, chief engineer of Shanghai Municipal Engineering Design and Research Institute (Group) Co., Ltd. said that at present, the drainage pipe network The management risk is greater, and the dredging method is backward; the structural and functional'disease' of the drainage pipe is serious, and the damaged and misplaced drainage pipe causes serious leakage of the pipe. "Taking the drainage pipeline in a district of Shanghai as an example in 2011, pipelines above moderate siltation accounted for 18.45% of the total pipeline length. On average, there was one structural ‘disease’ such as rupture and leakage every 1 kilometer.”

An industry source said that the sewage pipe network undertakes the task of collecting and transporting sewage, which is the key to the entire process of sewage treatment. Due to the relatively backward construction and management of sewage pipelines, there are problems such as pipeline leakage, misconnection, mixed connection, overflow pollution, and inadequate industrial wastewater. The effective collection efficiency of the pipeline network is relatively low, and some collections are not real. Sewage, sewage treatment plant low influent concentration. At the same time, there is a large investment in the construction and renovation of the sewage pipe network system, and the spatial data of the layout of the sewage pipe network is missing in many places, making it difficult to rebuild.

Innovate the "factory-network-river integration" governance model

Sewage treatment is a systematic and comprehensive task. Sewage treatment quality and efficiency enhancement can never be solved by a single factor, but the result of a variety of factors. It involves the improvement of sewage plant standards, the transformation of rain and sewage diversion, sewage Mud treatment and disposal.

"Although the sewage treatment capacity, treatment volume and treatment rate have been continuously improved, it does not mean that the sewage treatment effect will increase simultaneously." Jing Yuanyuan said that the sewage treatment industry needs to innovate the "factory-network-river integration" system governance 3. Specialized management model, which is conducive to the overall planning and coordination of sewage treatment planning, and is also conducive to improving the operational efficiency of sewage treatment.

Li An, an expert from the China Municipal Environmental Protection Industry Association Urban Sewage Treatment Branch, also said that the sewage treatment quality and efficiency transformation has changed from the initial sewage treatment plant standard upgrade to the pipe network, pump station, plant and other system-wide quality improvement and efficiency. "The implementation of the "factory-network-river integration" governance model provides assurance for the safe and efficient operation of sewage treatment and maximizes environmental, economic, and social benefits."

Why should we implement the "factory-network-river integration" model? An industry insider believes that sewage collection, treatment, and discharge is a systematic process in itself, but the current drainage pipe network and sewage treatment operation are managed separately. This system design leads to Issues such as different rights and responsibilities of various parties and lack of systematic management have emerged.

At the same time, due to the serious "heavy water and light sludge" phenomenon in the past, sludge treatment and disposal progressed slowly, and sludge treatment and disposal is an indispensable and important part of the sewage treatment process. Zhang Chen said that the current sludge treatment and disposal technology is single, and most of them are landfilled only after simple concentration and dehydration treatment; the technical route is imperfect, and the scientific treatment technology route system oriented to the final safe disposal of sludge has not yet been formed; The utilization rate is low, and biomass energy is not effectively utilized. "It is urgent to build a technical route system oriented to safe disposal and resource utilization to improve the top design level of sludge treatment."

In addition, key technological breakthroughs can also boost the quality and efficiency of the wastewater treatment industry. Li An believes that it is necessary to intensify technical research and development in areas such as accurate detection of drainage pipes, dredging treatment and in-situ repair, and aerobic granular sludge technology to provide strong technical support for improving the quality and efficiency of sewage treatment. At the same time, it is necessary to build an efficient supervision platform for urban drainage and sewage treatment systems, clarify the supervision indicator system, and implement source monitoring and alarm, operation quality supervision of urban sewage treatment plants, operation and maintenance management supervision of sewage collection pipe networks, etc.