Utilizing Green Walls for In-Situ Greywater Treatment

Abstract

Agricultural industrialization in the 21st century has presented acute strains on freshwater globally, and population growth has driven modern farming practices towards the overuse of already scarce water resources. This coupled with the increased popularity of water-intensive green infrastructure has led to the focus of this project: integrating greywater recycling through vegetated walls to minimize freshwater use and promote sustainable wastewater management. By selecting wetland species accustomed to a saturated environment, we designed walls that were well suited to absorbing the varied contaminants of greywater, which was modeled after effluent from sources like laundry machines, showers, and dishwashers. We evaluated the treatment performance of the walls through the U.S. Environmental Protection Agency (EPA) and Maryland Department of the Environment (MDE) guidelines for pH, turbidity, total organic carbon (TOC/NPOC), total nitrogen (TN), chemical oxygen demand (COD), and plant health was monitored through qualitative metrics. The development of green walls with region-specific native plants may allow for greater accessibility in communities local to Maryland, and may be used in future applications of green infrastructure planning.