Modular System for Waste Treatment, Water Recycling, and Resource Recovery

Because resupply of commodities for long duration space missions would be prohibitively expensive and could take an extensive length of time to reach habitats in orbit around or on other planetary bodies, it is critical that astronauts have the ability to recycle and reuse local waste streams to provide resources such as clean water, fuel, and nutrients for growing plants. Scientists at Kennedy Space Center and the University of South Florida have developed a technology that addresses this critical mission need. The modular system design incorporates all wastewater streams and some food waste including urine water, hygiene water, humidity condensate, Sabatier water, fecal waste, laundry water, and organic food waste. These sources are fed simultaneously into the system, and a function-driven, sequential purification process occurs. The primary processes include carbon conversion, phase separation (solid/liquid/gas), disinfection, nutrient/salts management, and salts balancing to generate a clean water stream. The heart of the closed-loop bio-regenerative system is an anaerobic membrane bioreactor (AnMBR), which takes raw wastewater streams and utilizes an anaerobic microbial consortium to carry out the breakdown of the organic matter. An ultrafiltration membrane captures and destroys pathogenic bacteria and viruses. The AnMBR system generates a clean water stream containing fertilizer constituents which can be used to cultivate either microalgae (for food, pharma/nutraceuticals, fuel or bioplastics) in photobioreactors or crops in hydroponic systems. The system also generates methane and hydrogen gas which can be used for fuel (or conversion to bioplastics), and CO2 which can be used to support plant growth. Current water recovery and purification systems aboard the International Space Station are open loop (requiring external inputs) and inefficient. Additionally, organic wastes (i.e., fecal and food wastes) are currently not recycled, thus adding additional waste processing and hazardous conditions for astronauts. This is not a viable approach for long duration space habitats and missions. The Modular System for Waste Treatment, Water Recycling, and Resource Recovery technology addresses these problems using a completely closed-loop system of modular subsystems that combine to treat and recycle wastewater streams and organic food waste to produce clean water, gases that can be used for fuel, and fertilizer constituents that can be utilized for plant growth.