Modular System for Waste Treatment, Water Recycling, and Resource Recovery
Environment
Modular System for Waste Treatment, Water Recycling, and Resource Recovery (KSC-TOPS-100)
Compact modular system can perform waste treatment, water recycling, and resource recovery in small spaces
Overview
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.
The Technology
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.
Benefits
- Compact design.
- Modular design can be easily transported and rapidly reassembled onsite.
- EXPRESS rack system is a universal design that can used for space vehicles and habitats.
Applications
- Space stations
- Surface habitats
- Space crew transit vehicles (e.g., capsules)
- Ships
- Buildings
- Homes
- Remote outposts
Similar Results
Contaminated Water Treatment
This invention is a system and associated method that is a two step process. It provides a contaminant treatment pouch, referred to as a urine cell or contaminant cell that converts urine or another liquid containing contaminants into a fortified drink, engineered to meet human hydration, electrolyte and caloric requirements. It uses a variant of forward osmosis (FO) to draw water from a urine container into the concentrated fortified drink as part of a recycling stage. An activated carbon pretreatment removes most organic molecules. Salinity of the initial liquid mix (urine plus other) is synergistically used to enhance the precipitation of organic molecules so that activated carbon can remove most of the organics. A functional osmotic bag is then used to remove inorganic contaminants. If a contaminant is processed for which the saline content is different than optimal for precipitating organic molecules, the saline content of the liquid should be adjusted toward the optimal value for that contaminant.
Wastewater Treatment and Remediation
NASA's system was developed for smaller-scale, space-based applications. However, the technology is scalable for larger industrial and municipal water treatment applications. Implementation of the Ammonia Recovery System could significantly reduce nitrogen content from water treatment processes, meaningfully improving the quality of water. This system offers a novel way to reduce nitrogen water pollutants, while allowing for the nitrogen to be collected and reused- reducing environmental and public health risks and providing an environmentally friendly fertilizer option. NASAs environmental solutions work to sustain life on earth through space based technology
The adaptable nature of this system gives it potentially broad applications in a wide variety of industries; it is particularly ideal for on-site remediation of wastewater in places like condo complexes, hotels and water parks. Current methods of ammonia recovery could not meet NASAs mission requirements, so a new process was devised to optimize for high ammonia selectivity, simplicity, low volume , low power usage and zero contaminants in the effluent. To do this, NASA designed a novel regenerable struvite-formation system for the capture of ammonia. This system has three primary functions:
1) Removal of ammonia from wastewater using a media that is highly selective for ammonia
2) Capture of the ammonia for later use (e.g., as a fertilizer)
3) Regeneration of the capture media for reuse in the system
Air Revitalization for Vacuum Environments
The NASA life support system uses a regenerable vacuum swing adsorption process, known as Sorbent-Based Air Revitalization (SBAR), to separate water and carbon dioxide for disposal. The SBAR system is an adsorbent-based swing bed system that has been optimized to provide both humidity and carbon dioxide control for a spacecraft cabin atmosphere.
The system comprises composite silica gel and zeolite-packed beds for adsorption and a bypass system for flow control. Under normal operating conditions, the disposal system would require a high-quality vacuum environment to operate. Improvements to the SBAR system include an enhanced inherent capacitance that extends the operation time within a non-vacuum environment for up to 4.5 hours. Flight time can be further expanded with multiple SBAR systems to allow for system regeneration. By scheduling periodic thermal regenerations—nominally during sleep periods—the SBAR technology may be suitable for missions of unlimited duration.
Microwave-Based Water Decontamination System
Bacterial contamination of water systems used in microgravity is a major issue for NASA because biofilms can clog or interfere with water system functions and bacterial ingestion can be harmful to astronaut health. To address this problem, NASA innovators developed a microwave based technology to purify contaminated water by eradicating and eliminating bacteria that grows in systems that generate potable water, in equipment utilizing cooling loops and heat exchangers, and removing bacterial contamination that is present on a variety of surfaces. This decontamination system is chemical free and requires minimal to no consumables.
Initial testing identified a specific microwave frequency band and exposure times for killing bacteria (Burkholderia cepacia) and biofilm. Test results show that exposing static water to microwave energy for 90 seconds can effectively kill waterborne bacteria and biofilm within a water filtration system. Additional testing, using a circulating water test bed, demonstrated that microwave energy at the selected frequency can effectively eradicate waterborne bacteria within 30 seconds. This technology could be further developed into a portable, lightweight system for use in remote locations as well as commercial space applications. The microwave decontamination system could also be added to existing water systems to extend the life of the system.
Algae Photobioreactor Using Floating Enclosures With Semi-Permeable Membranes
The photobioreactors allow light to enter through their transparent upper surface and optimizes the efficiency of light utilization with a light-reflective lower surface inside. Deployed in the marine environment, the gradient between the freshwater inside the system and the saltwater outside drives forward osmosis. The water removed through semi-permeable (forward osmosis) membranes is cleaned as it is released into the marine environment. In addition, this process concentrates nutrients in the algae medium to stimulate growth, and concentrates the algae to facilitate harvesting. The harvested algae can be used to make biofuels, fertilizer, animal food, or other products. The photobioreactors are intended for use in naturally or artificially protected marine environments with small waves and gentle currents. The system can also be used in artificial brine pools and freshwater basins or reservoirs, however in freshwater the forward osmosis feature cannot be used.
