Browsing by Author "Taylor, E. Jennings"
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Item In-Situ Electrochemical Generation and Utilization of Hydrogen Peroxide for Disinfection(51st International Conference on Environmental Systems, 7/10/2022) Vijapur, Santosh; Hall, Timothy; Taylor, E. Jennings; More, Santosh; Sweterlitsch, Jeffrey; Ewert, Michael; L. Castro-Wallace, Sarah; Byrne, Vicky; Dunbar, Brandon; Nguyen, Hang; Smith, MelanieDisinfection needs to meet personal hygiene requirements at the International Space Station (ISS) is currently accomplished through the use of pre-packaged, disposable, wetted wipes, which represent an appreciable carry-along mass and disposal burden. However, as human missions travel further into the solar system the availability of resources to resupply will be diminished. Therefore, next-generation system should use onboard utilities to create on demand disinfectants thereby reducing the dependence on earth-based supplies and further eliminating storage and disposal problems. Accordingly, we are developing an in-situ approach to electrochemically generate hydrogen peroxide disinfecting solution utilizing onboard life support supplies (Air/Water) to neutralize surface microorganisms present in closed living systems. As discussed within our 2019 and 2021 ICES papers (ICES-2019-38; ICES-2021-273), we have continued to improve our TRL by scaling the electrochemical generation production process and validating the system in a zero-gravity parabolic loop flight test. In this paper/presentation we will demonstrate a system that can achieve over 1 L of 2 w/w% peroxide per day with DI water and air reactor feeds. These electrolytes were then sent to NASA for microbial control property characterization. Overall, the electrochemical peroxide generation system offers a more economical and practical alternative, with the disinfectant being generated on demand and in-situ (using available life support materials (Air/Water)); and applied to reusable cloths. The specific application of interest to this program is crew contact surfaces in space vehicles, but this approach could be utilized for waste water disinfection, heat exchanger biofouling remediation, and laundry applications. The peroxide generation system will also be able to address Earth-based needs in various settings such as field hospitals, restaurants, military, warehouses, movie theatres, among many others. Acknowledgements: Financial support of NASA Contracts No. NNX16CA43P and NNX17CJ12C are acknowledged.Item In-Situ Resource Utilization for Electrochemical Generation of Hydrogen Peroxide for Disinfection(50th International Conference on Environmental Systems, 7/12/2021) Vijapur, Santosh; Hall, Timothy; Taylor, E. Jennings; Radhakrishnan, Rajeswaran; Wang, Dan; Snyder, Stephen; Skinn, Brian; Cabrera, Carlos; Duarte, Armando Pe�aDisinfection needs to meet the personal hygiene requirements of interplanetary travel community in space vehicles is currently accomplished through the use of pre-packaged, disposable, wetted wipes, which represent an appreciable carry-along mass and disposal burden. There is a stated need to develop a system that could use onboard utilities to create on demand disinfectants thereby reducing the astronaut�s dependence on earth-based supplies and further eliminating storage and disposable problems. Within this context, we are developing an in-situ approach to electrochemically generate hydrogen peroxide disinfectant utilizing onboard life support supplies (Air/Water) to eliminate many of the surface contaminants present in closed living systems. As discussed within our 2018 paper we have demonstrated the potential to produce up to 1 w/w% peroxide with DI water and oxygen utilizing our optimized system. This paper will build upon that work and discuss the results from our zero-gravity flight test and system scale-up activities. Furthermore, the system has been shown to be amenable to utilize various water streams (DI, RO, and Tap water) with or without I or Ag additions as well as air or pure oxygen supplies. Finally, we have scaled the system to produce up to 6 L per day of 1 w/w% peroxide and are working to increase the output concentration up to 6 w/w% peroxide. The peroxide generation system offers a more economical and practical alternative, with the disinfectant solution being generated on demand and in-situ; and applied to reusable cloths, reducing both the carried and disposed mass associated with the disinfection process. The peroxide generation system demonstrates a strong potential to address a critical need of disinfection within ISS and will also be able to address Earth-based needs in various settings such as hospitals, restaurants, movie theatres, among many others. Acknowledgements: Financial support of NASA Contracts NNX16CA43P, NNX17CJ12C, and 80NSSC20C0070.Item In-Situ Resource Utilization for Electrochemical Generation of Hydrogen Peroxide for Disinfection(49th International Conference on Environmental Systems, 2019-07-07) Vijapur, Santosh; Hall, Timothy; Taylor, E. Jennings; Wang, Dan; Snyder, Stephen; Skinn, Brian; Cabrera, Carlos; Peña Duarte, Armando; Sweterlitsch, JeffreyTechnological innovations are essential to enable energy-efficient maintenance of closed air, water, and waste systems for interplanetary travel with limited resupply options and microgravity living conditions. One particular need for the interstellar travel community is disinfection to meet personal hygiene requirements. At present, surface disinfection in space vehicles is accomplished through the use of pre-packaged, disposable, wetted wipes, which represent an appreciable carry-along mass and disposal burden. Therefore, next-generation system should use onboard utilities to create on demand disinfectants thereby reducing the astronaut’s dependence on earth based supplies and further eliminating storage and disposable problems. Within this context, we are demonstrating a technology to generate disinfectants that can neutralize or eliminate many of the contaminants while improving system maintenance and disinfection. Specifically, we are exploring an electrochemical system for generating hydrogen peroxide, a well-established disinfectant with non-toxic decomposition products (viz., oxygen and water), that is safe enough for human contact to be sold commercially as a 3 w/w% solution. This concept is founded on the electrochemical reduction of oxygen to hydrogen peroxide using readily available on-board supplies of oxygen and water. Initial trials confirmed that the developed system utilizing oxygen and RO water can generate >1 w/w% peroxide concentration. The proposed hydrogen peroxide generation system offers a more economical and practical alternative, with the disinfectant solution being generated on demand and in-situ; and applied to reusable cloths, reducing both the carried and disposed mass associated with the disinfection process. A zero gravity flight test is scheduled for March 2019 to validate the technology in microgravity environments. The specific application of interest to this program is crew contact surfaces in space vehicles, but this approach could be utilized for waste water disinfection, heat exchanger biofouling remediation, and laundry applications. Acknowledgements: Financial support of NASA Contracts No. NNX16CA43P and NNX17CJ12C are acknowledged.Item Next Generation Water Recovery for a Sustainable Closed Loop Living(50th International Conference on Environmental Systems, 7/12/2021) Vijapur, Santosh; Hall, Timothy; Taylor, E. Jennings; Liu, Danny; Snyder, Stephen; Cabrera, Carlos; Vazquez, Delmaliz Barreto; Cardona, Wilfredo; Perez, Arnulfo RojasThe Environmental Control and Life Support System (ECLSS) within the International Space Station (ISS) recovers and recycles up to 85% water from human waste with lifetime/durability limitations requiring the supply of hazardous chemicals and filter units to treat the system components to maintain their targeted performance. However, as human missions travel further into the solar system the availability of resources to resupply will be diminished. Therefore, next-generation system is required to reduce waste, recover water, and improve efficiency. Accordingly, Faraday Technology and the University of Puerto Rico (UPR) are developing a bio-electrochemical system to efficiently treat urine waste streams with ~95% urea to improve the water recovery system�s efficiency/durability. Within this system, a bioreactor will convert urea from the waste water to ammonia by hydrolysis: NH2(CO)NH2 + H2O ? 2NH3 + CO2 (1) The effluent of the bioreactor will then flow through the ammonia oxidation reactor: 2NH3 ? N2 + 3H2 (2) thus, generating urea free waste water effluent for further enhancement. Faraday and UPR have (1) leveraged existing knowledge to design and test the bio-electrochemical reactor; (2) explored the efficacy of (P. Vulgaris) bacteria for bioreactor, (3) evaluated electrocatalyst for ammonia reactor, (4) optimized the efficiency and waste water treatment rate with urine simulants. By doing so, the ammonia reactor demonstrated nearly 100% ammonia removal during optimized operation. The data from bench scale system was utilized to design and build a demonstration-scale bio-electrochemical reactor capable of meeting NASA specifications. A zero-gravity flight test is scheduled for May 2021 to validate the technology in microgravity. Furthermore, this technology has the potential to be compatible with the existing ECLSS infrastructure and be an integral part of the closed loop living systems required for long term life support on NASA�s manned space missions. Acknowledgements: Financial support of NASA Contract NNX17CA30P and 80NSSC18C0222.Item Removal of Urea and Ammonia from Real Human Urine using Bio-electrochemical Reactor system for Closed Loop Environments.(51st International Conference on Environmental Systems, 7/10/2022) Cardona Vélez, Wilfredo J; Cabrera Matinez, Carlos R.; Toranzos, Gary A; Vijapur, Santosh H; Hall, Tim; Taylor, E. JenningsWater recycling system with improved efficiencies to satisfy the water demand in a closed loop environment is required by NASA's Environmental Control and Life Support Systems (ECLSS). Wastewater recycling system in the ECLSS has a water reclamation efficiency limitation of approximately 90%. Therefore, next-generation technologies are required to improve the ECLSS in spacecraft and future planetary space stations for the Moon or Mars. Accordingly, the University of Puerto Rico, in collaboration with Faraday Technology, are developing a sustainable continuous bio-electrochemical process for urea and ammonia removal from wastewater. that will aid the water reclamation process by limiting precipitation events that result from the presence of urea in the urine. This approach will convert the urea to ammonia in a continuous enzyme-based bioreactor, then the bioreactor effluent will travel through an electrochemical oxidation reactor where the ammonia would be oxidized to H2 and N2. The bioreactor uses P. vulgaris microbial enzyme that consumes the urea, through urease catalyzed hydrolysis. Urease hydrolysis generates an ammonia rich bioreactor effluent that can be electrochemically treated . Our work has demonstrated that the resulting effluent from the bio-electrochemical system has significantly reduced ammonia and urea concentration, when testing synthetic urine feed streams. Furthermore, the semi-continuous operation of the bio-electrochemical system has been validated during a zero-gravity parabolic loop flight test flown in May 2021. Recently, the bio-electrochemical system was evaluated with real human urine, and we intend to report those results at ICES. Overall, this project demonstrates the potential of a bio-electrochemical system that can improve the lifetime and durability of the water recovery system used in closed loop living environments. Acknowledgements: This project is partially supported by the National Aeronautics and Space Administration (NASA) Training Grant No. NNX15AI11H. Also, NASA Contract NNX17CA30P, 80NSSC18C0222.Item Reversible Electrochemical Mirror for Thermal Management Systems(50th International Conference on Environmental Systems, 7/12/2021) Garich, Holly; Taylor, E. Jennings; Liu, Danny; Peng, Thomas; Tench, Morgan; Davis, JamesReversible electrochemical mirror devices function through reversible redox reactions that alternate between deposition of a highly reflective thin metallic film (hence the term mirror) and complete oxidation of the metallic film during the erasure cycle. These devices generally utilize transparent, conductive substrates such as those based on indium tin oxide type films applied to glass or plastic transparent substrates, though other substrate materials could be used in the build of these devices. Reversible electrochemical mirror devices may be built to either facilitate reflection and transmission or reflection and absorption of radiation sources depending on the nature of the counter electrode used. Reversible electrochemical mirror devices may be used in space based thermal management systems as well as terrestrial applications including auto-dimming mirrors for the automotive industry, electrochromic windows for the aviation industry, and smart glass for the architectural industry. Room temperature ionic liquid electrolytes are an attractive for reversible electrochemical mirror devices used in space-based systems due to their ability to facilitate reversible electrodeposition reactions in addition to their negligible vapor pressure, excellent chemical and thermal stability and their large electrochemical windows. Simple, two electrode cells were built using transparent electrodes with electrically conductive films (i.e. indium tin oxide, platinum and silver) and air and moisture stable room temperature ionic liquid electrolytes for development of operating conditions that facilitate long cycle lifetimes in simple reversible electrochemical mirror devices. In this work, use of pulsed electric fields have been demonstrated to promote high cycle lifetimes when compared to operation under steady state (constant voltage electric fields). By tuning the pulse electric field, the mass transport properties and crystallization process are controlled, yielding fine grained silver deposits, which is expected to be important for the subsequent stripping process, which leads to long cycle lifetimes in comparison to steady state operation.