The wastewater treatment plant of the Project was former Datong Yudong Wastewater Treatment Project, whose biochemical treatment systems (including the previous #5 tank, i.e. the FSBBR flow bed biological reaction tank, the previous #4 tank, i.e. hydrolysis acidification +HAF anaerobic reaction tank) were to undergo renovation and optimization to meet the needs due to economic development and higher water quality standard in its service area. After the renovation, the maximum standalone capacity of #5 tank reaches 30,000m³/d, while its process is changed from FSBBR to BioDopp; the maximum standalone capacity of #4 tank is preferably no higher than 40,000m³/d. The maximum capacity of biochemical treatment in parallel is 60,000m³/d. The maximum capacity of #4 tank (including the hydrolysis acidification tank) and #5 tank running in series is no less than 40,000m³/d.