The researchers modified a wavy constructed wetland by adding aeration tubes to improve the removal of ammonium nitrogen. By increasing dissolved oxygen levels and promoting nitrification, they achieved over 90% nitrification efficiency. Recirculating the effluent back into the wetland significantly increased total nitrogen removal rates, reaching up to 50%. This method enhanced the wetland's ability to handle high hydraulic loads and organic loads, making it more effective in treating wastewater.