This technical achievement focuses on solving the technical problems caused by low BOD5/TN ratio, high SS/BOD5 ratio, low temperature in winter, and land shortage. It innovatively develops and demonstrates the application of "enhanced pretreatment → efficient primary sedimentation fermentation tank → (ring ditch type) improved A2/O → suspended filler enhanced nitrification (IFAS) → chemical collaborative phosphorus removal → mechanical filtration" urban sewage treatment system Level A stable compliance technology and key equipment products. This technical achievement was first integrated and continuously improved in the standard upgrading and renovation project of Lucun Sewage Treatment Plant in Wuxi City with a design scale of 200,000 m3/d. After the standard upgrading and renovation, the effluent water stably reached the first-level A emission standard. This technical achievement has been authorized for 3 invention patents.

 The   popularization and application of this technical achievement has promoted the smooth progress of upgrading and upgrading urban sewage treatment plants in key river basins across the country. At present, the engineering application scale of core process technologies and equipment products has accumulated to more than 10 million m3/d, which has improved the level of first-level A compliance for treated effluent. and operational stability have greatly reduced the emissions of nitrogen and phosphorus pollutants into rivers and lakes, saved project land, and reduced project investment and operating costs. It will produce more significant social and environmental benefits in the future construction and upgrading of sewage treatment plants.