A vertical subsurface flow constructed wetland was studied for treating wastewater. It effectively removed organic matter, with a 71%-87% removal rate. However, it had a low removal rate for ammonia (NH3-N), less than 10%. Temperature didn't affect phosphorus removal much, with a 52%-77% removal rate. But soil pH and oxygen levels limited phosphorus removal capacity. The wetland's performance was influenced by factors like COD loading, reaeration, and operation parameters.