VOLUME III, Number 5, May 1973


Russian scientists working on water recycling and purification problems
for the Soviet space ship and orbiting station program have decided on
silver as the best long-term sanitizing agent. Researching the problems
of water storage over periods of several months, as well as purification
for immediate use, they determined that ionized silver provides the
safest and longest lasting method of transforming polluted waste in
potable water.

A significant fact in support of their decision to use silver for
purification was their experimental confirmation of the absence of
toxicity in the silver treated water. In lengthy experiments on animals
they found that 100 parts and 200 parts of silver per billion in
drinking water does not accumulate in the organism and does not produce
any detrimental effect on the functioning of the organs or systems of
the experimental animals.
This was also confirmed by year long experiments on volunteer human
subjects. The concentration of silver used in these tests . . . 100
parts and 200 parts per billion . . . is in striking comparison with the
10 to 50 parts per billion of silver found in potable water and in
swimming pools treated by silver purification systems in the United

The scientists, Drs.. S. V. Chizhov. S. P. Pak, N. N. Sitnikova and Y.
U. Koloskova. tried many methods of purifying regenerated water but all
except the silver system proved unsatisfactory over the long run.
Ultra-violet rays and ultra-high-frequency sound reduced micro-organisms
by as much as 97% but water thus treated failed to meet standards of
acceptibility if the water were stored for any considerable period of
time. Chlorine, which is widely used to kill bacteria, requires dosages
in thousands of parts per billion compared to the 100 ppb and 200 ppb
used in the Russian tests; the chlorine itself is a pollutant for
certain water uses and it often is dangerous to store or handle. In sum,
the Russians found silver to be the safest sterilizing agent, stable,
and long-lasting.

The research also showed that decontaminated water may change in
reaction to its container. They concluded that polyethylene containers
are suitable for the short-term storage of silver-ionized water. For
long-term storage of a few months or more, they decided it is better to
use a vessel made of polymers of the fluorine plastic group, or metal
containers of vitreous enameled aluminum alloy (for lightness in a space

Included among the many experiments conducted by Dr. Chizhov and his
associates were those designed to assay the purification of water
condensed from the atmosphere inside a simulated space vehicle. The
quantity of microorganisms in the regenerated water before the
introduction of the ionized silver varied from 200 to 1,900
microbiological parts per milliliter. Tests of the water made 15 to 20
minutes after contact with the ionized silver showed in most cases that
in this 15 to 20 minute period, full sterilization had occurred. In a
few cases, complete purity was achieved only after 30 to 40 minutes of
exposure. Study of controlled samples of the water after 24 to 72 hours
showed the continned and complete absence of microorganisms.

The Russians also suggested that the regeneration of water from the
byproducts of human activity seems feasible through the use of silver
ions as the decontamination agent. In this application they found it
desirable to introduce silver ions into the water with the aid of
various filtering materials in order to provide the slow dissolving of
the silver. Designing the filter and selecting the form in which silver
is introduced will allow engineers to establish any desired
concentration of silver ions in a given volume of water, they believe.

Pioneers' Use of Silver