Browsing by Author "Vijapur, Santosh"
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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 Urea Removal and Ammonia Detection Evaluation through Synthetic Urine Continuous Bio-Electrochemical Reactor for Closed Loop Environments(50th International Conference on Environmental Systems, 7/12/2021) V�lez, Wilfredo J Cardona; Perez, Arnulfo Rojas; Barreto-Vazquez, Delmaliz; Pag�n-Jim�nez, �ngel S.; Toranzos, Gary; Cabrera, Carlos R.; Vijapur, Santosh; Hall, Timothy D.; Taylor, E. JenningA wastewater recycling system with enhanced efficiencies is needed to satisfy the water need in a closed loop environment required by NASA�s Environmental Control and Life Support Systems (ECLSS). Wastewater treatment and water-recovery system within the ECLSS has an efficiency limitation of approximately 90% of water reclamation. To provide self-sustainable technology that would enhance the ECLSS in spacecraft and future space-bases in the Moon and Mars, this project focuses on urea removal and conversion to ammonia from wastewater by using a bioreactor system. As such, the University of Puerto Rico (UPR), in collaboration with Faraday Technology, are designing a fully automated continuous bio-electrochemical process. That will aid on water reclamation process improving the removal of urea through a continuous flow bioreactor in series with an electrochemical reactor for the ammonia oxidation. The prototype of the bioreactor model is being based on a shake-flask reactor and the advantage of P. vulgaris to metabolize urea. The automated bioreactor process continuously feds basal synthetic human urine (BSHU) using microbial enzymes to convert urea to ammonia through urease catalyzed hydrolysis. Thus, generating an ammonia rich effluent as by product, that can be further treated through an electrochemical reactor (e.g., alkaline ammonia fuel cell or electrolyzer). This later electrochemical reactor may be integrated to the downstream bioreactor process for the proper ammonia oxidation reaction to nitrogen from the bioreactor�s effluent. This will produce an effluent with significantly reduced ammonia and urea concentration in the water stream. Resulting data from a bench bioreactor system will be utilized to design a zero-gravity flight test to be flown on May 2021, evaluating the electrochemical results from bacteria and BSHU matrix in microgravity environment. This provides further understanding and innovative development for future integration of our bioreactor in a ECLSS system for closed loop environment interactions for water reclamation.