XiaoyiRiver in Xiongan New Area is one of the eight rivers flowing into Baiyang Lake. In order to purify water in Xiaoyi River, the river estuary constructed wetland project was constructed, the treatment capacity of which was 20×104m3/d. The treatment process was combined by“pre-precipitation ecological pond + subsurface wetland + surface wetland + submerged plant pond ”, the project would become the second largest horizontal subsurface wetland in China. Prediction based on design specification and engineering experience, if the wetland inflow could meet the class Ⅳ standard of Environmental Quality Standards for Surface Water (GB 3838-2002), total phosphorus(TP) removal would be required not lower than 30% in winter; if the inflow could meet the class Ⅴ standard, the effluent should meet the class Ⅳ standard;if the inflow quality is worse than the class Ⅴ standard, TP removal should be above 30% in winter, and the other major over-standard pollutants removal ought to be more than 20%. The area of this project was 1.98 km2, the construction cost of this project was 2 150 yuan/m3, and the operation cost was 0.098 yuan/m3.
