A compact, modular wastewater treatment system for non-potable reuse of household greywater

Triangle Environmental proposes a compact, modular system for rapid, fully-automated treatment of domestic greywater for non-potable onsite reuse. There is an expected 40% global shortfall between supply and demand of water by 2030. The current standard of household water use, in which potable water is used for all applications, is therefore unsustainable. Alternate water sources can be used for a variety of non-potable uses within and outside a building. Replacing just the demand for toilet flushing with non-potable water can offset approximately 25% of the total potable water use in a residential building, and up to 75% in a commercial building. Other potential non?potable demands include irrigation, cooling/heating applications, process water, and clothes washing. This project focuses on modifying a technology already well-developed for onsite blackwater treatment towards rapid greywater treatment and implementing it at the household scale for applications with a high likelihood of rapid adoption (toilet flushing and laundry), thereby reducing household consumption of potable water by ~40% (73,000 L per year for a family of four). Preliminary data demonstrates the feasibility of using this three-stage treatment process for greywater; the studies in this Phase I proposal are aimed at making specific modifications to each subprocess to 1) increase energy efficiency and lower operating cost, 2) specify design parameters for greywater applications to improve component performance and lifetime, and 3) ensure reliability of the disinfection process. Global water recycling and reuse markets were projected to double from $12.2 billion in 2016 to $22.3 billion in 2021. Greywater reuse regulations in the United States are expanding to allow for more onsite non-potable reuse applications driven by the increasing pressure on water resources. The proposed greywater system provides an in?residence, on-demand alternative to existing cost-prohibitive and high-maintenance greywater treatment systems. In addition, many of these existing decentralized greywater treatment systems are installed in rural or peri-urban areas where there is greater access to land for larger footprint systems. Therefore, there is a quickly emerging market opportunity for an appliance-like greywater treatment system that can be utilized by residences and businesses in dense, urban settings.