Constructed wetlands in frost-free areas can effectively remove nitrogen and phosphorus from wastewater. A study in Guangdong Province, China, found that plant uptake plays a significant role in nutrient removal, with Arundo donax being particularly efficient. The longer a wetland has been operating and the higher the wastewater volume it treats, the better the nutrient removal. Plant biomass contributes to removing nitrogen and phosphorus, with aboveground plant organs having high uptake concentrations. The study showed that influent concentrations and plant biomass are key factors influencing nutrient removal efficiency in constructed wetlands.