The researchers explored ways to improve the efficiency of vertical flow constructed wetlands for treating household wastewater. They tested different methods like adding special materials to absorb nutrients, adjusting water levels, and using a new type of wetland design. They found that adding certain materials can help remove pollutants, but some methods were more effective than others. For example, a new wetland design called Cyclic Batch Subsurface Wetland showed the best results in removing nitrogen and preventing clogs. Overall, these enhancements can make the wetlands better at cleaning wastewater and protecting the environment.