Date of Graduation
12-2021
Document Type
Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
Degree Level
Graduate
Department
Chemical Engineering
Advisor/Mentor
Beitle, Robert R. Jr.
Committee Member
Wickramasinghe, S. Ranil
Second Committee Member
Roe, Larry A.
Third Committee Member
Muirhead, Dean
Keywords
biocide dosing system; long-term space mission; silver biocide; space exploration; spacecraft water management; water recovery system
Abstract
The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in the WPA to inhibit the growth of microorganisms in the product water. The dialysis-membrane-based system has to supply silver ions into the potable water at concentrations ranging from 200 to 400 parts per billion during the entire water processing time. The silver ion delivery system has been prototyped by repurposing dialysis membranes used for the separation/purification of low molecular weight solutes. Consequently, the low molecular weight cutoff of the dialysis membrane controls the silver ion release from a concentrated silver ion reservoir and does not require any power. Both computational and experimental studies were conducted to examine the performance of the silver ion delivery and the feasibility of integrating this technology in future spacecraft water recovery units. The preliminary results from this investigation show that the dialysis-membrane-based passive biocide delivery system can supply sufficient silver ions to a stream of deionized water. Nevertheless, the outflow might require dilution, and the membrane may need to undergo preconditioning for optimal performance, especially for reuse.
Citation
Garcia Fernandez, R. E. (2021). Preliminary Development of The Dialysis-Membrane-based Passive Biocide Delivery System for Spacecraft Water Recovery Units. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/4322
Included in
Aerodynamics and Fluid Mechanics Commons, Space Vehicles Commons, Transport Phenomena Commons