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Madidrop for Passive Silver DosingMadidrop is a rectangular ceramic tablet originally designed to dose a 10-20-liter volume of water with silver to act as a biocide for remote communities with unreliable water sources. Silver as a biocide is a proposed method to control bacteria on the International Space Station or future Artemis missions. This would replace iodine currently used due to issues with a dual biocide system in place between Russian and US segments and the extra cost of iodine removal required before consumption. NASA has been reviewing this Madidrop technology and its potential application with a water reclamation system on orbit to dose silver after purifying the water. While there are a couple alternative methods to dosing silver on station, this method is like the existing passive dosing method used currently to dose iodine. Tests conducted characterize the manufacturer’s original intent to leave the tablet in a tank for a specified amount of time before removing and testing alternative passive flow-through methods. Passive flow testing involved two options: keeping the tablet intact or crushing the tablet into smaller particle sizes to increase the surface area while varying particle sizes. The results of these tests revealed a large amount of silver output at first that quickly reduced to a constant lower output within a reasonable dosing concentration range. The initial high concentration peaks after a couple days of quiescence and could be useful for shocking the initial tank water contents. Madidrop used as a passive particle doser could act as a stand-in replacement for iodine in future spaceflight water reclamation systems.
Document ID
20240004192
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Ryan Ogilvie
(Johnson Space Center Houston, Texas, United States)
Date Acquired
April 8, 2024
Subject Category
Man/System Technology and Life Support
Report/Patent Number
ICES-2024-131
Meeting Information
Meeting: 53rd International Conference on Environmental Systems (ICES)
Location: Louisville, KY
Country: US
Start Date: July 21, 2024
End Date: July 25, 2024
Sponsors: Leidos (United States), International Conference on Environmental Systems
Funding Number(s)
WBS: 830724.06.01.02.06
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Technical Review
External Peer Committee
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