Technical guide for water purification of constructed wetlands

A few days ago, the Ministry of Ecology and Environment issued the "Technical Guide for Water Purification of Constructed Wetlands" (hereinafter referred to as the "Guide"), which is used to guide the relevant work of water purification of constructed wetlands. Relevant responsible comrades of the Department of Water Ecology and Environment of the Ministry of Ecology and Environment answered questions from reporters on the background, principles and main contents of the formulation of the Guide.

Q: What is the background and significance of the Guidelines?

A: The 14th Five-Year Plan is the first five-year plan to embark on a new journey to comprehensively build a modern socialist country and promote the building of a beautiful China. To further strengthen ecological protection and restoration of rivers and lakes, The Technical Outline for the preparation of the 14th Five-Year Plan for Water Ecological Environment Protection in Key River Basins and the Guide to the Storage of the Central Ecological Environment Fund Project Reserve (2020) issued by the Ministry of Finance and the Ministry of Agriculture both regard constructed wetlands as an important measure to improve the ecological environment of rivers and lakes. The "Guiding Opinions on Promoting the Utilization of Sewage Resources" jointly issued by ten ministries and commissions also regards constructed wetlands as an important way to realize the utilization of sewage resources.

In recent years, Shandong, Anhui, Yunnan, Shanghai, Qinghai and other places have taken the lead in building constructed wetlands in key nodes such as the downstream of sewage treatment plant outfalls, river inlets into lakes, and branches into main streams according to local conditions, using ecological methods to further improve the drainage and micro-polluted river water after treatment standards, and achieving good environmental, ecological and social benefits. At present, the above places have raised the relevant practice to local standards.

At the national level, the former Ministry of Environmental Protection and the Ministry of Housing and Urban-Rural Development respectively issued industry standards such as the "Technical Specifications for Constructed Wetland Sewage Treatment Engineering" and "Technical Regulations for Natural Sewage Treatment Engineering" in 2010 and 2017, but the above standards regard constructed wetlands as high-concentration sewage treatment facilities. It has not adapted to the new requirements of improving the water quality of wastewater treatment plants to meet the standard of drainage and micro-pollution, achieving the water environment target of rivers and lakes, or the reuse of reclaimed water under the current new situation; In addition, the above standards focus on design, and the operation and maintenance of constructed wetlands are not considered enough.

Therefore, it is necessary to summarize local beneficial experience in a timely manner, formulate and introduce relevant technical documents, and better guide the relevant work of water purification of constructed wetlands in the country.

Q: What is the main purpose of the Guide?

A: The main consideration of the "Guide" is from the perspective of "effective, easy to use and solve problems", through the systematic guidance of the whole process of the water purification project of constructed wetlands from design, construction, acceptance to operation and maintenance, to prevent and dispose of common problems of constructed wetlands, stabilize the water purification effect of constructed wetlands, and achieve long-term effective operation.

Q: Everyone is interested in the compilation of the Guide. Could you briefly introduce the main contents of the Guide?

A: The Guide consists of four chapters: The first chapter is the general provisions, which clarifies the purpose, scope of application and basic principles of the Guide, and defines the main terms. The second chapter to the fourth chapter is the main part, which is the design, construction, acceptance, operation and maintenance of the constructed wetland water purification. The chapter "Water purification design of constructed wetland" mainly makes detailed provisions on the overall design, process design, auxiliary engineering, etc., including the standard specifications to be implemented, the applicable process types and design parameters. In the chapter "Construction and Acceptance", the requirements and standards for the construction process of the main project, auxiliary project and supporting facilities are systematically specified, and the management and technical requirements for the completion of environmental protection acceptance are clearly defined. The "Operation and maintenance" chapter puts forward the ability and qualification requirements for the operation and maintenance units and operation management personnel of constructed wetlands, and stipulates the conditions and standards that should be met in production debugging, daily operation and maintenance, safety production, emergency management, monitoring and recording, etc. In addition, a list of suggested measures is put forward for the classification of common problems of constructed wetlands.