From September 2 to 7, the 2021 China Service Trade Fair was held in Beijing. As one of the series of activities of the service trade fair, the white paper release and seminar on enterprises in the new development pattern of double circulation, sponsored by Xinhuanet and the Economic Research Institute of the Academy of Social Sciences, was held on the same time on the 3rd. At the meeting, the white paper on enterprises with dual cycle new development pattern (hereinafter referred to as the "white paper") was officially released. Beikong water sludge double return AOA deep nitrogen and phosphorus removal technology (hereinafter referred to as "AOA new technology") is an innovative case of high-quality development of environmental industry, which has become a case selected in the white paper in the environmental protection industry.

Building a new development pattern is a major strategic task related to China's overall development as proposed in the 14th five year plan and the 2035 long-term goal outline. In this context, Xinhuanet and the Economic Research Institute of the Chinese Academy of Social Sciences set up a research group to go deep into the industry *, carry out research and exchange, collect typical cases of representative enterprises in helping to build a new development pattern, and form the research results of the white paper of enterprises in a double cycle new development pattern. The purpose is to condense industrial wisdom and provide reference and inspiration for helping to build a new development pattern.

With the proposal of the "double carbon" goal, the low-carbon water industry is on the way. Improving the efficiency of water treatment is an indispensable link to improve the efficiency of domestic large-scale circulation. The academician workstation jointly built by Beikong water affairs and Peng Yongzhen, academician of the * Engineering Institute, based on the characteristics of domestic water treatment, has successfully developed AOA new technology for 6 years and carried out large-scale production applications in Shandong, Guangdong and other places. The overall effect is good. Under the background of the "30 · 60" double carbon target, it has a broader application prospect and practical promotion value.

Different from the characteristics of foreign sewage, most of China's water pipelines are of mixed flow system. AOA new technology is a technology to effectively solve the nitrogen removal of water with low carbon nitrogen ratio under the background of mixed flow system, aiming at the unstable sewage concentration.

At present, the activated sludge process is the core technology of sewage treatment. The conventional process is limited by the sludge reflux ratio, and the total nitrogen removal rate is a difficult problem in the industry. The AOA new technology places the anoxic zone behind, and the sewage flows through the anaerobic aerobic anoxic (A-O-A) biological reaction tank in turn. The TN removal efficiency is significantly improved, the effluent effect is stable and better than the a standard, and the NH3-N and TN are stable and better than the Beijing standard a standard.

This technology can recycle the carbon source in the sludge, reduce the aeration volume of biochemical treatment while saving the cost of chemical input, and achieve the dual treatment effect of nitrogen and phosphorus removal and energy saving and emission reduction. It is a powerful support technology for the sewage treatment plant to achieve the goal of "carbon neutralization".

In addition, the application of this technology will also effectively reduce the output of sludge, treat the "pain of sludge" from the source, further reduce the carbon emissions in the whole life cycle of sewage treatment, and increase the water treatment efficiency by 50% on average, thus promoting the construction of a green industrial chain.

Technological innovation is the key to achieving green and low-carbon development, and also the key to achieving the "double carbon" goal. Under the background of carbon neutralization, the new energy-saving and consumption reduction technology for nitrogen and phosphorus removal is the demand orientation of the whole industry. It is understood that AOA new technology now has the technical conditions for large-scale engineering promotion. At the same time, in the process of large-scale application, it can further overcome the technical problems of software and hardware, and form technologies and products with independent intellectual property rights.

(responsible editors: Zhao Zhuqing, Chen Jian)