Plant disposition in surface flow wetlands affects the purification of eutrophicated water. In a study at the Beijing Wildlife Rescue Center, it was found that Eichhornia crassipes is most effective at removing total phosphorus and total nitrogen, while Nymphoides peltatum and Oenanthe javanica are less efficient. The removal rates of total phosphorus, total nitrogen, chemical oxygen demand, and total suspended solids varied among different plant species. The pH values of certain plants were notably lower than others. Overall, the study showed that plant arrangement plays a significant role in the purification of circulating water in wetlands.