A study looked at how well wetlands with different plants and materials can clean up nitrogen and phosphorus from sewage. They found that wetlands with zeolite and anthracite were better at removing these pollutants than those without. Wetlands with Typha orientalis, Nelumbo nucifera, and Canna glauca plants were the most effective, with Canna glauca being the best. Nymphaea alba-Ceratophyllum demersum wetlands worked better than Eichhornia crassipes-Ceratophyllum demersum ones. The researchers suggest using Canna glauca first, followed by Typha orientalis, Nelumbo nucifera, and Phragmites australis, and ending with Eichhornia crassipes-Ceratophyllum demersum for the best results.