Date of Graduation
5-2019
Document Type
Thesis
Degree Name
Bachelor of Science in Chemical Engineering
Degree Level
Undergraduate
Department
Chemical Engineering
Advisor/Mentor
Ackerson, Michael
Committee Member/Reader
Beitle, Robert R.
Committee Member/Second Reader
Penney, William R.
Abstract
As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team decided to design a controlled release system capable of meeting the constraints listed in the problem statement. By using a membrane similar to those within dialysis devices a system was designed to deliver silver ions to a stream of water that requires arguably no power and is exceptionally lightweight. While the silver delivery system fulfilled the constraints of the WERC problem statement, our team also examined the use of resins like those contained in the current Microbial Check Valve (MCV). Resin substitutes capable of selective silver sorption are recommended as replacements for those within the current MCV to prevent backwards microbial diffusion through the system. Multiple designs will be presented in this paper. First, our membrane-controlled release silver delivery system (SDS) is presented to specifically address the WERC Task 1 deliverables. Second, a proposed upgrade to the ISS water system is described that replaces the ion exchange resin beds with silver-selective media prevent microbial contamination of water in the potable water system of the spacecraft. Given the extreme lightweight nature of the SDS, nil power requirement, and minor modification to the existing system, Hogs In Space has delivered a highly effective method to deliver and control silver based on the WERC Task 1 requirements.
Keywords
water filter system; spacecraft water system; service learning
Citation
Garcia, R. E. (2019). Silver-based Microbial Check Valve for Spacecraft Potable Water Systems. Chemical Engineering Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/cheguht/151
Honor Thesis Summary
Included in
Environmental Engineering Commons, Service Learning Commons, Space Habitation and Life Support Commons
