Ecological and Economic Benefits

• The composite artificial wetland system of Wastewater Purification Terraces in Handan Garden Expo Park has shown significant water purification and cost optimization capabilities, with water quality improving from poor Class V to Class II (GB 3838-2002), with the best effects in summer.
• Different types of wetlands have their own advantages in pollutant removal. Horizontal Surface Flow wetlands have the best purification effects on COD and BOD₅, and open water surfaces increase the concentration of dissolved oxygen; Upflow Vertical Subsurface Flow wetlands optimize the nitrification and denitrification processes by extending the length of buried pipes, showing significant effects on the removal of NH₃-N; Horizontal Subsurface Flow wetlands increase the removal rate of TP by extending the water flow path; TN purification requires the series connection of multiple types of wetlands (alternating aerobic and anaerobic) to achieve the best results.
• The optimized T3 system wetland design parameters show that the area of Horizontal Surface Flow wetland is 452 m², the area of Horizontal Subsurface Flow wetland is 3129.57 m², and the area of Upflowed Vertical Subsurface Flow wetland is 1545.44 m², with the total project cost reduced from 2.46 million yuan to 1.87 million yuan.

Data Source:

Han J. Water Purification Effects and Cost Optimization of Different Types of Artificial Wetlands - A Case Study of Wastewater Purification Terraces in Handan Garden Expo Park [M]. Peking University, 2024.