Study on the Application and Sustainable Benefits of Greywater Management Integrate with Green Walls

In the context of global climate change, population growth and socio-economic development, many cities are facing increasing water stress and water scarcity. Greywater, which makes up a substantial proportion of domestic wastewater, has the potential to be reused for non-potable purposes. Therefore, greywater management has received increasing attention in recent years and combining it with green walls is considered an innovative approach. Based on the perspective of sustainable development and by reviewing a series of existing studies, this paper analyzes the technology, application, and perpetual benefits of using green walls for greywater management. The feasibility of this approach is confirmed by modular and standing green wall facilities and systems that have been commercially applied. Greywater treatment with green walls provides a range of environmental benefits by removing more than half of the major pollutants and meeting local non-potable water quality standards in a cost-effective manner. At the same time, the use of greywater to irrigate green wall plants could benefit their growth to a certain extent, which can also have positive socio-economic benefits. However, the lack of infrastructure, technology, or policy support in some developing or underdeveloped regions may have a negative impact on its application. Nevertheless, in the future, the combination of greywater management and green walls has a relatively wide application and promotion prospects in water-scarce urban areas.