Electrolytic water sterilizer controls microbial contamination in manned spacecraft. Individual sterilizer cells are self-contained and require no external power or control. The sterilizer generates silver ions which do not impart an unpleasant taste to water

Albright, C. F.

Gillerman, J. B.

English

NASA Technical Reports Server

December 1968	 Brief 68-10555 
NASA TECH BRIEF 
NASA Teèh Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Electrolytic Silver Ion Cell Sterilizes Water Supply 
An electrolytic water sterilizer has been developed 
for control of microbial contamination in manned 
spacecrafts. Individual sterilizer cells are self-contained 
and require no external power or control. The com-
pactness and light weight of the units (measuring 2.5 
inches in diameter x 4 inches in length and weighing 
0.6 pound) and absence of external mechanisms make 
it possible to integrate such sterilizers with the potable 
water supply or waste water system in confined areas. 
The sterilizer generates silver ions in concentra-
tions of 50 ppb. (parts per billion) to 100 ppb in the 
water flow system, the desired concentration being 
adjusted as a function of the average water flow rate. 
After installation of a unit, no maintenance is re-
quired. Operation of the unit is self-limiting, preclud-
ing damage to the system if water ceases to flow. A 
shunt is provided for on-off functions and monitoring 
of current flow. Unit life expectancy is 9000 hours 
without a change of the power supply batteries. 
Laboratory tests of the sterilizer under simulated 
conditions have demonstrated essentially complete kill 
within 8 hours of Staphylococcus aureus and Escherichia 
co/i bacteria presnt in initial concentrations of ap-
proximately 5 xlO organisms per milliliter. 
Silver ions in concentrations of 50 to 100 ppb, which 
are nontoxic when ingested, have been recognized for 
many years as an effective bactericide. Since a steriliza-
tion unit for spacecraft water systems must operate in 
zero gravity, consume little electrical power, and require
no heat, elaborate controls, or material replacement, 
the use of silver ions in a spacecraft sterilizer has many 
advantages over other possible sterilization methods. 
Many of the advantages of the new sterilizer, including 
the advantage that the silver ions do not impart an un-
pleasant taste to the water, can be realized also in non-
space applications. This water sterilizer should also be 
of value to biological laboratories, pharmaceutical 
companies, and underwater craft. 
Note: 
Design details and test results are contained in Report 
NASA-CR-65738 which is available from: 
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Price $3.00 
Reference: B68-10555 
Patent status: 
This invention is owned by NASA, and a patent ap-

plication has been filed. Royalty-free, nonexclusive
licenses for its commercial use will be granted by

NASA. Inquiries concerning license rights should be

made to NASA, Code GP, Washington, D.C. 20546.
Source: J.B. Gillerman and C.F. Albright 
of The Garrett Corporation (AiResearch Mfg. Div.) 
under contract to

Manned Spacecraft Center 
(MSC-1 1827) 
Category 01 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19680000511 2020-03-12T06:28:34+00:00Z


Electrolytic silver ion cell sterilizes water supply

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