Optimization of hydrophyte configuration route in constructed wetlands in China based on literature analysis

The constructed wetland has been widely used in the remediation of water environment pollution due to its low investment cost, efficient water purification and harmonious landscape. However, there is a lack of complete standardized route for the configuration of plants in constructed wetlands under different conditions. 465 hydrophyte combination data in 210 constructed wetland literatures were screened and analyzed by using the method of literature retrieval and analysis. Based on the analysis results, a five-step hydrophyte configuration route for constructed wetland was constructed, including single species determination, configuration and collocation, system construction, landscape configuration, and space configuration. The technical content of each configuration step and the proposed list of the available hydrophytes were put forward. In the step of single species determination, five species of aquatic plants (Acorus calamus, Canna indica, Phragmites communis, Typha orientalis, Iris tectorum) were identified as the predominant functional hydrophyte. In the step of configuration and collocation, hydrophyte combinations were made according to the nutrient salt concentration of incoming water. In the step of system construction, different types or winter hydrophyte were supplemented. In the step of landscape configuration, hydrophyte was supplemented according to flower color, flowering period, height and ornamental characteristics. In the step of space configuration, the space configuration of hydrophyte was made from nutrient salt removal effect, landscape effect, biodiversity of artificial wetland system, and resistance to hydraulic scouring. This hydrophyte configuration route can provide a reference for the standardization of the hydrophyte configuration during constructed wetland design.